Reorganize all.

40 files changed, 0 insertions, 3592 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
deleted file mode 100644
index 1764764..0000000
--- a/kernel/Makefile
+++ /dev/null
@@ -1,38 +0,0 @@
-
-AS = nasm
-ASFLAGS = -felf -g
-
-CC = i586-elf-gcc
-CFLAGS = -ffreestanding -O2 -std=gnu99 -Wall -Wextra -I . -I ./include -g -Wno-unused-parameter
-# CXX = i586-elf-g++
-# CXFLAGS = -ffreestanding -O3 -Wall -Wextra -I . -I ./include -fno-exceptions -fno-rtti
-LD = i586-elf-gcc
-LDFLAGS = -T linker.ld -ffreestanding -O2 -nostdlib -lgcc -Xlinker -Map=kernel.map
-
-OBJ = lib/string.o lib/printf.o lib/slab_alloc.o lib/mutex.o \
-	lib/hashtbl.o lib/buffer.o\
-	l0/loader.o l0/kmain.o l0/dbglog.o l0/sys.o \
-	l0/gdt.o l0/idt.o l0/interrupt.o l0/context_switch.o l0/thread.o \
-	l0/frame.o l0/paging.o l0/region.o l0/kmalloc.o
-OUT = kernel.bin
-
-all: $(OUT)
-
-$(OUT): $(OBJ)
-	$(LD) $(LDFLAGS) -o $@ $^
-
-%.o: %.s
-	$(AS) $(ASFLAGS) -o $@ $<
-
-%.o: %.c
-	$(CC) -c $< -o $@ $(CFLAGS)
-
-# %.o: %.cpp
-#	$(CXX) -c $< -o $@ $(CXFLAGS)
-
-clean:
-	rm */*.o || true
-mrproper: clean
-	rm $(OUT) || true
-
-rebuild: mrproper all
diff --git a/kernel/config.h b/kernel/config.h
deleted file mode 100644
index a0e59d3..0000000
--- a/kernel/config.h
+++ /dev/null
@@ -1,27 +0,0 @@
-#if !defined(__cplusplus)
-#include <stdbool.h>
-#endif
-
-#include <stddef.h>
-#include <stdint.h>
- 
-#if defined(__linux__)
-#error "This kernel needs to be compiled with a cross-compiler."
-#endif
- 
-#if !defined(__i386__)
-#error "This kernel needs to be compiled with a ix86-elf compiler"
-#endif
-
-#define IN_KERNEL
-
-#define K_HIGHHALF_ADDR ((size_t)0xC0000000)
-
-#define OS_NAME "macrO.Scope"
-#define OS_VERSION "0.0.1"
-
-// Comment to disable either form of debug log output
-#define DBGLOG_TO_SERIAL
-#define DBGLOG_TO_SCREEN
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/buffer.h b/kernel/include/buffer.h
deleted file mode 100644
index c47e2b4..0000000
--- a/kernel/include/buffer.h
+++ /dev/null
@@ -1,40 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-#include <stddef.h>
-
-// The buffer_t type is a simple reference-counted buffer type
-// enabling the creation, sharing, slicing and concatenation of buffers
-// without having to copy everything each time
-
-// Buffers are always allocated on the core kernel heap (kmalloc/kfree)
-
-// Once a buffer is allocated, its contents is immutable
-
-// Encoding and decoding functions for buffer contents are provided in
-// a separate file (encode.h)
-
-struct buffer;
-typedef struct buffer buffer_t;
-
-void buffer_ref(buffer_t*);				// increase reference counter
-void buffer_unref(buffer_t*);			// decrease reference counter
-
-size_t buffer_len(buffer_t* buf);
-size_t read_buffer(buffer_t* buf, char* to, size_t begin, size_t n);	// returns num of bytes read
-
-buffer_t* buffer_from_bytes(const char* data, size_t n);	// bytes are COPIED
-buffer_t* buffer_from_bytes_nocopy(const char* data, size_t n, bool own_bytes);	// bytes are NOT COPIED
-
-// these functions GIVE the buffer in order to create the new buffer, ie they do not increase RC
-// the buffer is NOT GIVED if the new buffer could not be created (ie retval == 0)
-buffer_t* buffer_slice(buffer_t* b, size_t begin, size_t n);
-buffer_t* buffer_concat(buffer_t* a, buffer_t* b);
-
-// these functions KEEP a reference on the buffer (ie RC is incremented)
-// the RC is NOT INCREMENTED if the new buffer cannot be created
-buffer_t* buffer_slice_k(buffer_t* b, size_t begin, size_t n);
-buffer_t* buffer_concat_k(buffer_t* a, buffer_t* b);
-
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/dbglog.h b/kernel/include/dbglog.h
deleted file mode 100644
index 2f670e8..0000000
--- a/kernel/include/dbglog.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#pragma once
-
-#include <config.h>
-
-void dbglog_setup();
-void dbg_print(const char* str);
-void dbg_printf(const char* format, ...);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/frame.h b/kernel/include/frame.h
deleted file mode 100644
index 9ffafb3..0000000
--- a/kernel/include/frame.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#pragma once
-
-#include <sys.h>
-
-// frame.h : physical memory allocator
-
-void frame_init_allocator(size_t total_ram, void** kernel_data_end);
-
-uint32_t frame_alloc(size_t n);		// allocate n consecutive frames (returns 0 on failure)
-void frame_free(uint32_t base, size_t n);
-
-void dbg_print_frame_stats();
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/gdt.h b/kernel/include/gdt.h
deleted file mode 100644
index a62d0db..0000000
--- a/kernel/include/gdt.h
+++ /dev/null
@@ -1,17 +0,0 @@
-#pragma once
-
-#include <stddef.h>
-#include <stdint.h>
-
-/*	The GDT is one of the x86's descriptor tables. It is used for memory segmentation.
-	Here, we don't use segmentation to separate processes from one another (this is done with paging).
-	We only use segmentation to make the difference between kernel mode (ring 3) and user mode (ring 0) */
-
-void gdt_init();
-
-#define K_CODE_SEGMENT 0x08
-#define K_DATA_SEGMENT 0x10
-#define U_CODE_SEGMENT 0x18
-#define U_DATA_SEGMENT 0x20
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/hashtbl.h b/kernel/include/hashtbl.h
deleted file mode 100644
index 16dfefb..0000000
--- a/kernel/include/hashtbl.h
+++ /dev/null
@@ -1,34 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-#include <stddef.h>
-#include <stdbool.h>
-
-// Simple hashtable structure (key -> void*)
-// Supports adding, seeking, removing
-// When adding a binding to the table, the previous binding for same key (if exists) is removed
-
-// TODO : possibility to allocate the hashtbl structure on any heap
-// (currently uses kmalloc/kfree)
-
-struct hashtbl;
-typedef struct hashtbl hashtbl_t;
-
-typedef size_t hash_t;
-typedef hash_t (*hash_fun_t)(const void*);
-typedef bool (*key_eq_fun_t)(const void*, const void*);
-
-hashtbl_t* create_hashtbl(key_eq_fun_t ef, hash_fun_t hf, size_t initial_size);	// 0 -> default size
-void delete_hashtbl(hashtbl_t* ht);
-
-int hashtbl_add(hashtbl_t* ht, void* key, void* v);	// non-null on error (OOM for instance)
-void* hashtbl_find(hashtbl_t* ht, void* key);		// null when not found
-void hashtbl_remove(hashtbl_t* ht, void* key);
-size_t hashtbl_count(hashtbl_t* ht);
-
-hash_t id_hash_fun(const void* v);
-hash_t str_hash_fun(const void* v);
-bool id_key_eq_fun(const void* a, const void* b);
-bool str_key_eq_fun(const void* a, const void* b);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/idt.h b/kernel/include/idt.h
deleted file mode 100644
index 8e84cea..0000000
--- a/kernel/include/idt.h
+++ /dev/null
@@ -1,79 +0,0 @@
-#pragma once
-
-/*	The IDT is the system descriptor table that tells the CPU what to do when an interrupt fires.
-	There are three categories of interrupts :
-	- Exceptions ; eg page fault, divide by 0
-	- IRQ : interrupts caused by hardware
-	- System calls : when an applications asks the system to do something */
-
-#include <config.h>
-
-#define IRQ0  0
-#define IRQ1  1
-#define IRQ2  2
-#define IRQ3  3
-#define IRQ4  4
-#define IRQ5  5
-#define IRQ6  6
-#define IRQ7  7
-#define IRQ8  8
-#define IRQ9  9
-#define IRQ10 10
-#define IRQ11 11
-#define IRQ12 12
-#define IRQ13 13
-#define IRQ14 14
-#define IRQ15 15
-
-#define EX_DIVIDE_ERROR                  0         // No error code
-#define EX_DEBUG                         1         // No error code
-#define EX_NMI_INTERRUPT                 2         // No error code
-#define EX_BREAKPOINT                    3         // No error code
-#define EX_OVERFLOW                      4         // No error code
-#define EX_BOUND_RANGE_EXCEDEED          5         // No error code
-#define EX_INVALID_OPCODE                6         // No error code
-#define EX_DEVICE_NOT_AVAILABLE          7         // No error code
-#define EX_DOUBLE_FAULT                  8         // Yes (Zero)
-#define EX_COPROCESSOR_SEGMENT_OVERRUN   9         // No error code
-#define EX_INVALID_TSS                  10         // Yes
-#define EX_SEGMENT_NOT_PRESENT          11         // Yes
-#define EX_STACK_SEGMENT_FAULT          12         // Yes
-#define EX_GENERAL_PROTECTION           13         // Yes
-#define EX_PAGE_FAULT                   14         // Yes
-#define EX_INTEL_RESERVED_1             15         // No
-#define EX_FLOATING_POINT_ERROR         16         // No
-#define EX_ALIGNEMENT_CHECK             17         // Yes (Zero)
-#define EX_MACHINE_CHECK                18         // No
-#define EX_INTEL_RESERVED_2             19         // No
-#define EX_INTEL_RESERVED_3             20         // No
-#define EX_INTEL_RESERVED_4             21         // No
-#define EX_INTEL_RESERVED_5             22         // No
-#define EX_INTEL_RESERVED_6             23         // No
-#define EX_INTEL_RESERVED_7             24         // No
-#define EX_INTEL_RESERVED_8             25         // No
-#define EX_INTEL_RESERVED_9             26         // No
-#define EX_INTEL_RESERVED_10            27         // No
-#define EX_INTEL_RESERVED_11            28         // No
-#define EX_INTEL_RESERVED_12            29         // No
-#define EX_INTEL_RESERVED_13            30         // No
-#define EX_INTEL_RESERVED_14            31         // No
-
-#define EFLAGS_IF		(0x1 << 9)
-
-typedef struct registers {
-	uint32_t ds;                  // Data segment selector
-	uint32_t edi, esi, ebp, useless_esp, ebx, edx, ecx, eax; // Pushed by pusha.
-	uint32_t int_no, err_code;    // Interrupt number and error code (if applicable)
-	uint32_t eip, cs, eflags, esp, ss; // Pushed by the processor automatically.
-} registers_t;
-
-typedef void (*isr_handler_t)(registers_t*);
-
-void idt_init();
-
-void idt_set_ex_handler(int number, isr_handler_t func);	//Set exception handler
-void idt_set_irq_handler(int number, isr_handler_t func);	//Set IRQ handler
-
-void dbg_dump_registers(registers_t*);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/kmalloc.h b/kernel/include/kmalloc.h
deleted file mode 100644
index a409865..0000000
--- a/kernel/include/kmalloc.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-#include <stddef.h>
-
-// Kernel memory allocator : one slab allocator for shared memory
-// Thread-safe.
-
-void kmalloc_setup();
-
-void* kmalloc(size_t sz);
-void kfree(void* ptr);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/multiboot.h b/kernel/include/multiboot.h
deleted file mode 100644
index 581337a..0000000
--- a/kernel/include/multiboot.h
+++ /dev/null
@@ -1,63 +0,0 @@
-#pragma once
-
-#define MULTIBOOT_HEADER_MAGIC          0x1BADB002
-#define MULTIBOOT_BOOTLOADER_MAGIC      0x2BADB002
-
-struct  multiboot_header_t{
-	unsigned long magic;
-	unsigned long flags;
-	unsigned long checksum;
-	unsigned long header_addr;
-	unsigned long load_addr;
-	unsigned long load_end_addr;
-	unsigned long bss_end_addr;
-	unsigned long entry_addr;
-};
-
-struct aout_symbol_table_t {
-	unsigned long tabsize;
-	unsigned long strsize;
-	unsigned long addr;
-	unsigned long reserved;
-};
-
-struct elf_section_header_table_t {
-	unsigned long num;
-	unsigned long size;
-	unsigned long addr;
-	unsigned long shndx;
-};
-
-struct multiboot_info_t {
-	unsigned long flags;
-	unsigned long mem_lower;
-	unsigned long mem_upper;
-	unsigned long boot_device;
-	unsigned long cmdline;
-	unsigned long mods_count;
-	unsigned long mods_addr;
-	union {
-		struct aout_symbol_table_t aout_sym;
-		struct elf_section_header_table_t elf_sec;
-	} u;
-	unsigned long mmap_length;
-	unsigned long mmap_addr;
-};
-
-struct module_t {
-	unsigned long mod_start;
-	unsigned long mod_end;
-	unsigned long string;
-	unsigned long reserved;
-};
-
-struct memory_map_t {
-	unsigned long size;
-	unsigned long base_addr_low;
-	unsigned long base_addr_high;
-	unsigned long length_low;
-	unsigned long length_high;
-	unsigned long type;
-};
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/mutex.h b/kernel/include/mutex.h
deleted file mode 100644
index 6814adf..0000000
--- a/kernel/include/mutex.h
+++ /dev/null
@@ -1,21 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-#define MUTEX_LOCKED 1
-#define MUTEX_UNLOCKED 0
-
-
-typedef uint32_t mutex_t;
-
-void mutex_lock(mutex_t* mutex);	//wait for mutex to be free
-int mutex_try_lock(mutex_t* mutex);	//lock mutex only if free, returns !0 if locked, 0 if was busy
-void mutex_unlock(mutex_t* mutex);
-
-// the mutex code assumes a yield() function is defined somewhere
-void yield();
-
-#define STATIC_MUTEX(name) static mutex_t name __attribute__((section("locks"))) = MUTEX_UNLOCKED;
-	
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/paging.h b/kernel/include/paging.h
deleted file mode 100644
index 44014a2..0000000
--- a/kernel/include/paging.h
+++ /dev/null
@@ -1,31 +0,0 @@
-#pragma once
-
-#include <sys.h>
-#include <stdbool.h>
-
-struct page_directory;
-typedef struct page_directory pagedir_t;
-
-
-void paging_setup(void* kernel_data_end);
-
-pagedir_t *get_current_pagedir();
-pagedir_t *get_kernel_pagedir();
-
-void switch_pagedir(pagedir_t *pd);
-
-// these functions are always relative to the currently mapped page directory
-uint32_t pd_get_frame(void* vaddr);		// get physical frame for virtual address
-int pd_map_page(void* vaddr, uint32_t frame_id, bool rw);		// returns nonzero on error
-void pd_unmap_page(void* vaddr);	// does nothing if page not mapped
-
-// Note on concurrency : we expect that multiple threads will not try to map/unmap
-// pages in the same region at the same time. It can nevertheless happen that
-// several threads try to map pages that belong to the same 4M-section, and in that
-// case both might require the allocation of a new PT at the same location. These
-// cases are well-handled (the pagedir_t type contains a mutex used for this)
-
-pagedir_t *create_pagedir();		// returns zero on error
-void delete_pagedir(pagedir_t *pd);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/printf.h b/kernel/include/printf.h
deleted file mode 100644
index b4e1c1b..0000000
--- a/kernel/include/printf.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#pragma once
-
-#include <stddef.h>
-#include <stdint.h>
-#include <stdarg.h>
-
-int snprintf(char* s, size_t n, const char* format, ...);
-int vsnprintf(char* s, size_t n, const char* format, va_list arg);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/region.h b/kernel/include/region.h
deleted file mode 100644
index 1fef582..0000000
--- a/kernel/include/region.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#pragma once
-
-// Kernel virtual memory region allocator
-
-// This is entirely thread-safe
-
-#include <sys.h>
-#include <paging.h>
-
-struct region_info;
-typedef void (*page_fault_handler_t)(pagedir_t *pd, struct region_info *r, void* addr);
-
-typedef struct region_info {
-	void* addr;
-	size_t size;
-	char* type;
-	page_fault_handler_t pf;
-} region_info_t;
-
-void region_allocator_init(void* kernel_data_end);
-
-void* region_alloc(size_t size, char* type, page_fault_handler_t pf);	// returns 0 on error
-region_info_t *find_region(void* addr);
-void region_free(void* addr);
-
-// some usefull PF handlers
-// default_allocator_pf_handler : just allocates new frames on page faults
-void default_allocator_pf_handler(pagedir_t *pd, struct region_info *r, void* addr);
-
-// some functions for freeing regions and frames
-// region_free_unmap_free : deletes a region and frees all frames that were mapped in it
-void region_free_unmap_free(void* addr);
-// region_free_unmap : deletes a region and unmaps all frames that were mapped in it, without freeing them
-void region_free_unmap(void* addr);
-
-void dbg_print_region_info();
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/slab_alloc.h b/kernel/include/slab_alloc.h
deleted file mode 100644
index eb9588d..0000000
--- a/kernel/include/slab_alloc.h
+++ /dev/null
@@ -1,44 +0,0 @@
-#pragma once
-
-// Self-contained piece of library : a slab allocator...
-// Depends on page_alloc_fun_t and page_free_fun_t : a couple of functions
-// that can allocate/free multiples of one page at a time
-
-#include <stdint.h>
-#include <stddef.h>
-#include <stdbool.h>
-
-#if defined(__linux__)
-//redefine necessary stuff
-#include <assert.h>
-#define ASSERT assert
-#define PAGE_SIZE 0x1000
-#include <stdio.h>
-#define dbg_printf printf
-#else
-#include <sys.h>	// this is macroscope
-#include <dbglog.h>
-#endif
-
-// expected format for the array of slab_type_t given to slab_create :
-// an array of slab_type descriptors, with last descriptor full of zeroes
-// and with obj_size increasing (strictly) in the array
-typedef struct slab_type {
-	const char *descr;
-	size_t obj_size;
-	size_t pages_per_cache;
-} slab_type_t;
-
-struct mem_allocator;
-typedef struct mem_allocator mem_allocator_t;
-
-typedef void* (*page_alloc_fun_t)(size_t bytes);
-typedef void (*page_free_fun_t)(void* ptr);
-
-mem_allocator_t* create_slab_allocator(const slab_type_t *types, page_alloc_fun_t af, page_free_fun_t ff);
-void destroy_slab_allocator(mem_allocator_t*);
-
-void* slab_alloc(mem_allocator_t* a, size_t sz);
-void slab_free(mem_allocator_t* a, void* ptr);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/string.h b/kernel/include/string.h
deleted file mode 100644
index 682b25a..0000000
--- a/kernel/include/string.h
+++ /dev/null
@@ -1,17 +0,0 @@
-#pragma once
-
-#include <stddef.h>
-#include <stdint.h>
-
-void *memcpy(void *dest, const void *src, size_t count);
-void *memset(void *dest, int val, size_t count);
-int memcmp(const void *s1, const void *s2, size_t n);
-void *memmove(void *dest, const void *src, size_t count);
-
-size_t strlen(const char *str);
-char *strchr(const char *str, char c);
-char *strcpy(char *dest, const char *src);
-char *strcat(char *dest, const char *src);
-int strcmp(const char *s1, const char *s2);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/sys.h b/kernel/include/sys.h
deleted file mode 100644
index c8721ec..0000000
--- a/kernel/include/sys.h
+++ /dev/null
@@ -1,57 +0,0 @@
-#pragma once
-
-#include <config.h>
-
-static inline void outb(uint16_t port, uint8_t value) {
-	asm volatile("outb %1, %0" : : "dN"(port), "a"(value));
-}
-
-static inline void outw(uint16_t port, uint16_t value) {
-	asm volatile("outw %1, %0" : : "dN"(port), "a"(value));
-}
-
-static inline uint8_t inb(uint16_t port) {
-	uint8_t ret;
-	asm volatile("inb %1, %0" : "=a"(ret) : "dN"(port));
-	return ret;
-}
-
-static inline uint16_t inw(uint16_t port) {
-	uint16_t ret;
-	asm volatile("inw %1, %0" : "=a"(ret) : "dN"(port));
-	return ret;
-}
-
-static inline void invlpg(void* addr) {
-	asm volatile("invlpg (%0)" : : "r"(addr) : "memory");
-}
-
-void panic(const char* message, const char* file, int line);
-void panic_assert(const char* assertion, const char* file, int line);
-#define PANIC(s) panic(s, __FILE__, __LINE__);
-#define ASSERT(s) { if (!(s)) panic_assert(#s, __FILE__, __LINE__); }
-
-#define BOCHS_BREAKPOINT asm volatile("xchg %bx, %bx")
-
-
-// Utility functions for memory alignment
-
-#define PAGE_SIZE		0x1000
-#define PAGE_MASK		0xFFFFF000
-#define PAGE_ALIGN_DOWN(x)	(((size_t)x) & PAGE_MASK) 
-#define PAGE_ALIGN_UP(x)  	((((size_t)x)&(~PAGE_MASK)) == 0 ? ((size_t)x) : (((size_t)x) & PAGE_MASK) + PAGE_SIZE)
-#define PAGE_ID(x)			(((size_t)x) / PAGE_SIZE)
-#define PAGE_SHIFT		12
-#define PT_SHIFT		10
-// PAGE_SHIFT + PT_SHIFT + PT_SHIFT = 32
-#define N_PAGES_IN_PT		1024
-#define PD_MIRROR_ADDR	0xFFC00000		// last 4MB used for PD mirroring
-#define LAST_KERNEL_ADDR	PD_MIRROR_ADDR
-#define FIRST_KERNEL_PT	(K_HIGHHALF_ADDR >> (PAGE_SHIFT+PT_SHIFT))	// must be 768
-
-#define MASK4			0xFFFFFFFC
-#define ALIGN4_UP(x)	((((size_t)x)&(~MASK4)) == 0 ? ((size_t)x) : (((size_t)x) & MASK4) + 4)
-#define ALIGN4_DOWN(x)	(((size_t)x)&MASK4)
-
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/thread.h b/kernel/include/thread.h
deleted file mode 100644
index 757ba00..0000000
--- a/kernel/include/thread.h
+++ /dev/null
@@ -1,46 +0,0 @@
-#pragma once
-
-#include <sys.h>
-#include <paging.h>
-#include <region.h>
-
-#define T_STATE_RUNNING		1
-#define T_STATE_PAUSED	 	2
-#define T_STATE_FINISHED	3
-
-#define KPROC_STACK_SIZE 0x8000	// 8Kb
-
-#define TASK_SWITCH_FREQUENCY	100		// in herz
-
-typedef struct saved_context {
-	uint32_t *esp;
-	void (*eip)();
-} saved_context_t;
-
-struct process;
-typedef struct thread {
-	saved_context_t ctx;
-	pagedir_t *current_pd_d;
-
-	uint32_t state;
-
-	region_info_t *stack_region;
-
-	struct process *proc;		// process : L1 data structure
-
-	struct thread *next_in_queue;
-} thread_t;
-
-typedef void (*entry_t)(void*);
-
-void threading_setup(entry_t cont, void* data);		// never returns
-thread_t *new_thread(entry_t entry, void* data);	// thread is PAUSED, and must be resume_thread'ed
-
-extern thread_t *current_thread;
-
-void yield();
-void pause();
-
-void resume_thread(thread_t *thread, bool run_at_once);
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/context_switch.s b/kernel/l0/context_switch.s
deleted file mode 100644
index 6738a03..0000000
--- a/kernel/l0/context_switch.s
+++ /dev/null
@@ -1,58 +0,0 @@
-[EXTERN kernel_stack_top]
-[EXTERN run_scheduler]
-
-[GLOBAL save_context_and_enter_scheduler]
-; void save_context_and_enter_scheduler(struct saved_context *ctx);
-save_context_and_enter_scheduler:
-	pushf
-	cli
-	pusha					; Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax
-
-	mov eax, cr3
-	push eax
-
-	mov eax, [esp+44]		; get address of saved_context structure
-	mov [eax], esp			; save esp
-	mov dword [eax+4], resume_saved_context		; save eip
-
-	mov esp, kernel_stack_top
-	jmp run_scheduler
-
-resume_saved_context:
-	pop eax
-	mov cr3, eax
-
-	popa
-	popf
-	ret
-
-[GLOBAL irq0_save_context_and_enter_scheduler]
-; meant to be called on IRQ0
-; general registers already saved by IRQ handler stub
-; flags already saved by interruption and interruptions disabled
-; only saves CR3
-irq0_save_context_and_enter_scheduler:
-	mov eax, cr3
-	push eax
-
-	mov eax, [esp+8]		; get address of saved_context structure
-	mov [eax], esp			; save esp
-	mov dword [eax+4], resume_saved_irq0_context		; save eip
-
-	mov esp, kernel_stack_top
-	jmp run_scheduler
-
-resume_saved_irq0_context:
-	pop eax
-	mov cr3, eax
-	ret
-
-
-[GLOBAL resume_context]
-resume_context:
-	mov eax, [esp+4]		; get address of saved context
-	mov esp, [eax]			; resume esp
-	mov ecx, [eax+4]		; jump to specified eip
-	jmp ecx
-
-; vim: set ts=4 sw=4 tw=0 noet :
diff --git a/kernel/l0/dbglog.c b/kernel/l0/dbglog.c
deleted file mode 100644
index e042625..0000000
--- a/kernel/l0/dbglog.c
+++ /dev/null
@@ -1,159 +0,0 @@
-#include <stdarg.h>
-#include <string.h>
-#include <printf.h>
-#include <mutex.h>
-
-#include <dbglog.h>
-#include <config.h>
-#include <sys.h>
-
-// ==================================================================
-
-#ifdef DBGLOG_TO_SCREEN
-
-static const size_t VGA_WIDTH = 80;
-static const size_t VGA_HEIGHT = 25;
-
-static uint8_t vga_color = 7;
-static uint16_t* vga_buffer = 0;
-static uint16_t vga_row = 0, vga_column = 0;
-
-static uint16_t make_vgaentry(char c, uint8_t color) {
-	uint16_t c16 = c;
-	uint16_t color16 = color;
-	return c16 | color16 << 8;
-}
-
-static void vga_putentryat(char c, uint8_t color, size_t x, size_t y) {
-	const size_t index = y * VGA_WIDTH + x;
-	vga_buffer[index] = make_vgaentry(c, color);
-}
-
-static void vga_update_cursor() {
-	uint16_t cursor_location = vga_row * 80 + vga_column;
-	outb(0x3D4, 14);	//Sending high cursor byte
-	outb(0x3D5, cursor_location >> 8);
-	outb(0x3D4, 15);	//Sending high cursor byte
-	outb(0x3D5, cursor_location);
-}
- 
-static void vga_init() {
-	vga_row = 0;
-	vga_column = 0;
-	vga_buffer = (uint16_t*) (K_HIGHHALF_ADDR + 0xB8000);
-
-	for (size_t y = 0; y < VGA_HEIGHT; y++) {
-		for (size_t x = 0; x < VGA_WIDTH; x++) {
-			vga_putentryat(' ', vga_color, x, y);
-		}
-	}
-
-	vga_update_cursor();
-}
-
-static void vga_scroll() {
-	for (size_t i = 0; i < VGA_WIDTH * (VGA_HEIGHT - 1); i++) {
-		vga_buffer[i] = vga_buffer[i + VGA_WIDTH];
-	}
-	for (size_t x = 0; x < VGA_WIDTH; x++) {
-		vga_putentryat(' ', vga_color, x, VGA_HEIGHT - 1);
-	}
-	vga_row--;
-}
-
-static void vga_newline() {
-	vga_column = 0;
-	if (++vga_row == VGA_HEIGHT) {
-		vga_scroll();
-	}
-}
- 
-static void vga_putc(char c) {
-	if (c == '\n') {
-		vga_newline();
-	} else if (c == '\t') {
-		vga_putc(' ');
-		while (vga_column % 4 != 0) vga_putc(' ');
-	} else {
-		vga_putentryat(c, vga_color, vga_column, vga_row);
-		if (++vga_column == VGA_WIDTH) {
-			vga_newline();
-		}
-	}
-}
- 
-static void vga_puts(const char* data) {
-	size_t datalen = strlen(data);
-	for (size_t i = 0; i < datalen; i++)
-		vga_putc(data[i]);
-
-	vga_update_cursor();
-}
-
-#endif	// DBGLOG_TO_SCREEN
-
-// ==================================================================
-
-#ifdef DBGLOG_TO_SERIAL
-
-#define SER_PORT 0x3F8		// COM1
-
-static void serial_init() {
-	outb(SER_PORT + 1, 0x00);		// disable interrupts
-	outb(SER_PORT + 3, 0x80);		// set baud rate
-	outb(SER_PORT + 0, 0x03);		// set divisor to 3 (38400 baud)
-	outb(SER_PORT + 1, 0x00);
-	outb(SER_PORT + 3, 0x03);		// 8 bits, no parity, one stop bit
-	outb(SER_PORT + 2, 0xC7);		// enable FIFO, clear them, with 14-byte threshold
-}
-
-static void serial_putc(const char c) {
-	while (!(inb(SER_PORT + 5) & 0x20));
-	outb(SER_PORT, c);
-}
-
-static void serial_puts(const char *c) {
-	while (*c) {
-		serial_putc(*c);
-		c++;
-	}
-}
-
-#endif	// DBGLOG_TO_SERIAL
-
-// ==================================================================
-
-STATIC_MUTEX(dbglog_mutex);
-
-void dbglog_setup() {
-	mutex_lock(&dbglog_mutex);
-#ifdef DBGLOG_TO_SCREEN
-	vga_init();
-#endif
-#ifdef DBGLOG_TO_SERIAL
-	serial_init();
-#endif
-	mutex_unlock(&dbglog_mutex);
-}
-
-void dbg_print(const char* str) {
-#ifdef DBGLOG_TO_SCREEN
-	vga_puts(str);
-#endif
-#ifdef DBGLOG_TO_SERIAL
-	serial_puts(str);
-#endif
-}
-
-void dbg_printf(const char* fmt, ...) {
-	va_list ap;
-	char buffer[256];
-
-	va_start(ap, fmt);
-	vsnprintf(buffer, 256, fmt, ap);
-	va_end(ap);
-
-	dbg_print(buffer);
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/frame.c b/kernel/l0/frame.c
deleted file mode 100644
index 489d010..0000000
--- a/kernel/l0/frame.c
+++ /dev/null
@@ -1,85 +0,0 @@
-#include <frame.h>
-#include <dbglog.h>
-
-#include <mutex.h>
-
-// TODO: buddy allocator
-// this is a simple bitmap allocator
-	
-#define INDEX_FROM_BIT(a) ((a)/(8*4))
-#define OFFSET_FROM_BIT(a) ((a)%(8*4))
-
-static uint32_t *frame_bitset;
-static uint32_t nframes, nused_frames;
-static uint32_t begin_search_at;
-
-void frame_init_allocator(size_t total_ram, void** kernel_data_end) {
-	nframes = PAGE_ID(total_ram);
-
-	frame_bitset = (uint32_t*)ALIGN4_UP((size_t)*kernel_data_end);
-	*kernel_data_end = (void*)frame_bitset + ALIGN4_UP(nframes / 8);
-
-	for (size_t i = 0; i < ALIGN4_UP(nframes / 8)/4; i++)
-		frame_bitset[i] = 0;
-
-	nused_frames = 0;
-
-	size_t kernel_pages = PAGE_ALIGN_UP((size_t)*kernel_data_end - K_HIGHHALF_ADDR)/PAGE_SIZE;
-	for (size_t i = 0; i < kernel_pages; i++) {
-		size_t idx = INDEX_FROM_BIT(i);
-		size_t ofs = OFFSET_FROM_BIT(i);
-		frame_bitset[idx] |= (0x1 << ofs);
-		nused_frames++;
-	}
-	begin_search_at = INDEX_FROM_BIT(kernel_pages);
-}
-
-STATIC_MUTEX(frame_allocator_mutex);
-
-uint32_t frame_alloc(size_t n) {
-	if (n > 32) return 0;
-
-	mutex_lock(&frame_allocator_mutex);
-	for (uint32_t i = begin_search_at; i < INDEX_FROM_BIT(nframes); i++) {
-		if (frame_bitset[i] == 0xFFFFFFFF) {
-			if (i == begin_search_at) begin_search_at++;
-			continue;
-		}
-
-		for (uint32_t j = 0; j < 32 - n + 1; j++) {
-			uint32_t to_test = (0xFFFFFFFF >> (32 - n)) << j;
-			if (!(frame_bitset[i]&to_test)) {
-				frame_bitset[i] |= to_test;
-				nused_frames += n;
-
-				mutex_unlock(&frame_allocator_mutex);
-				return i * 32 + j;
-			}
-		}
-	}
-	mutex_unlock(&frame_allocator_mutex);
-	return 0;
-}
-
-void frame_free(uint32_t base, size_t n) {
-	mutex_lock(&frame_allocator_mutex);
-
-	for (size_t i = 0; i < n; i++) {
-		uint32_t idx = INDEX_FROM_BIT(base + i);
-		uint32_t ofs = OFFSET_FROM_BIT(base + i);
-		if (frame_bitset[idx] & (0x1 << ofs)) {
-			frame_bitset[idx] &= ~(0x1 << ofs);
-			nused_frames--;
-		}
-	}
-	if (INDEX_FROM_BIT(base) < begin_search_at)
-		begin_search_at = INDEX_FROM_BIT(base);
-
-	mutex_unlock(&frame_allocator_mutex);
-}
-
-void dbg_print_frame_stats() {
-	dbg_printf("Used frames: %d/%d\n", nused_frames, nframes);
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/gdt.c b/kernel/l0/gdt.c
deleted file mode 100644
index eadde5f..0000000
--- a/kernel/l0/gdt.c
+++ /dev/null
@@ -1,90 +0,0 @@
-#include <gdt.h>
-#include <string.h>
-
-#define GDT_ENTRIES 6	// The contents of each entry is defined in gdt_init.
-
-/* 	One entry of the table */
-struct gdt_entry {
-	uint16_t limit_low;
-	uint16_t base_low;
-	uint8_t base_middle;
-	uint8_t access;
-	uint8_t granularity;
-	uint8_t base_high;
-} __attribute__((packed));
-typedef struct gdt_entry gdt_entry_t;
-
-/*	Structure defining the whole table : address and size (in bytes). */
-struct gdt_ptr {
-	uint16_t limit;
-	uint32_t base;
-} __attribute__((packed));
-typedef struct gdt_ptr gdt_ptr_t;
-
-/*	The TSS is used for hardware multitasking.
-	We don't use that, but we still need a TSS so that user mode process exceptions
-	can be handled correctly by the kernel.	*/
-struct tss_entry {
-	uint32_t prev_tss;   // The previous TSS - if we used hardware task switching this would form a linked list.
-	uint32_t esp0;       // The stack pointer to load when we change to kernel mode.
-	uint32_t ss0;        // The stack segment to load when we change to kernel mode.
-	uint32_t esp1;       // Unused...
-	uint32_t ss1;
-	uint32_t esp2;
-	uint32_t ss2;
-	uint32_t cr3;
-	uint32_t eip;
-	uint32_t eflags;
-	uint32_t eax;
-	uint32_t ecx;
-	uint32_t edx;
-	uint32_t ebx;
-	uint32_t esp;
-	uint32_t ebp;
-	uint32_t esi;
-	uint32_t edi;
-	uint32_t es;         // The value to load into ES when we change to kernel mode.
-	uint32_t cs;         // The value to load into CS when we change to kernel mode.
-	uint32_t ss;         // The value to load into SS when we change to kernel mode.
-	uint32_t ds;         // The value to load into DS when we change to kernel mode.
-	uint32_t fs;         // The value to load into FS when we change to kernel mode.
-	uint32_t gs;         // The value to load into GS when we change to kernel mode.
-	uint32_t ldt;        // Unused...
-	uint16_t trap;
-	uint16_t iomap_base;
-} __attribute__((packed));
-typedef struct tss_entry tss_entry_t;
-
-// ========================= //
-// Actual definitions
-
-static gdt_entry_t gdt_entries[GDT_ENTRIES];
-static gdt_ptr_t gdt_ptr;
-
-/*	For internal use only. Writes one entry of the GDT with given parameters. */
-static void gdt_set_gate(int num, uint32_t base, uint32_t limit, uint8_t access, uint8_t gran) {
-	gdt_entries[num].base_low = (base & 0xFFFF);
-	gdt_entries[num].base_middle = (base >> 16) & 0xFF;
-	gdt_entries[num].base_high = (base >> 24) & 0xFF;
-
-	gdt_entries[num].limit_low = (limit & 0xFFFF);
-	gdt_entries[num].granularity = (limit >> 16) & 0x0F;
-	gdt_entries[num].granularity |= gran & 0xF0;
-	gdt_entries[num].access = access;
-}
-
-/*	Write data to the GDT and enable it. */
-void gdt_init() {
-	gdt_ptr.limit = (sizeof(gdt_entry_t) * GDT_ENTRIES) - 1;
-	gdt_ptr.base = (uint32_t)&gdt_entries;
-
-	gdt_set_gate(0, 0, 0, 0, 0);					//Null segment
-	gdt_set_gate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF);		//Kernel code segment	0x08
-	gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);		//Kernel data segment	0x10
-	gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);		//User code segment		0x18
-	gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);		//User data segment		0x20
-
-	asm volatile ("lgdt %0"::"m"(gdt_ptr):"memory");
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/idt.c b/kernel/l0/idt.c
deleted file mode 100644
index 2f244e3..0000000
--- a/kernel/l0/idt.c
+++ /dev/null
@@ -1,253 +0,0 @@
-#include <idt.h>
-#include <gdt.h>
-#include <sys.h>
-#include <string.h>
-#include <dbglog.h>
-
-struct idt_entry {
-	uint16_t base_lo;		//Low part of address to jump to
-	uint16_t sel;			//Kernel segment selector
-	uint8_t always0;
-	uint8_t type_attr;			//Type
-	uint16_t base_hi;		//High part of address to jump to
-} __attribute__((packed));
-typedef struct idt_entry idt_entry_t;
-
-struct idt_ptr {
-	uint16_t limit;
-	uint32_t base;
-} __attribute__((packed));
-typedef struct idt_ptr idt_ptr_t;
-
-#define GATE_TYPE_INTERRUPT 14		// IF is cleared on interrupt
-#define GATE_TYPE_TRAP 15			// IF stays as is
-
-#define GATE_PRESENT (1<<7)
-#define GATE_DPL_SHIFT 5
-
-
-void isr0();
-void isr1();
-void isr2();
-void isr3();
-void isr4();
-void isr5();
-void isr6();
-void isr7();
-void isr8();
-void isr9();
-void isr10();
-void isr11();
-void isr12();
-void isr13();
-void isr14();
-void isr15();
-void isr16();
-void isr17();
-void isr18();
-void isr19();
-void isr20();
-void isr21();
-void isr22();
-void isr23();
-void isr24();
-void isr25();
-void isr26();
-void isr27();
-void isr28();
-void isr29();
-void isr30();
-void isr31();
-
-void irq0();
-void irq1();
-void irq2();
-void irq3();
-void irq4();
-void irq5();
-void irq6();
-void irq7();
-void irq8();
-void irq9();
-void irq10();
-void irq11();
-void irq12();
-void irq13();
-void irq14();
-void irq15();
-
-void syscall64();
-
-// ************************************************************
-// Handler code
-
-static idt_entry_t idt_entries[256];
-static idt_ptr_t idt_ptr;
-
-static isr_handler_t irq_handlers[16] = {0};
-static isr_handler_t ex_handlers[32] = {0};
-
-/*	Called in interrupt.s when an exception fires (interrupt 0 to 31) */
-void idt_exHandler(registers_t *regs) {
-	if (ex_handlers[regs->int_no] != 0) {
-		ex_handlers[regs->int_no](regs);
-	} else {
-		//TODO: make sure all exceptions happenning in userspace do not cause kernel panic...
-		dbg_printf("Unhandled exception: %i\n", regs->int_no);
-		dbg_dump_registers(regs);
-		PANIC("Unhandled exception");
-	}
-} 
-
-/*	Called in interrupt.s when an IRQ fires (interrupt 32 to 47) */
-void idt_irqHandler(registers_t *regs) {
-	if (regs->err_code > 7) {
-		outb(0xA0, 0x20);
-	}
-	outb(0x20, 0x20);
-
-	dbg_printf("IRQ %i\n", regs->err_code);
-	if (irq_handlers[regs->err_code] != 0) {
-		irq_handlers[regs->err_code](regs);
-	}
-}
-
-/* Caled in interrupt.s when a syscall is called */
-void idt_syscallHandler(registers_t *regs) {
-	dbg_printf("Syscall %i\n", regs->int_no);
-	// do nothing, yet.
-}
-
-/*	For internal use only. Sets up an entry of the IDT with given parameters. */
-static void idt_set_gate(uint8_t num, void (*fun)(), uint8_t type) {
-	uint32_t base = (uint32_t)fun;
-
-	idt_entries[num].base_lo = base & 0xFFFF;
-	idt_entries[num].base_hi = (base >> 16) & 0xFFFF;
-
-	idt_entries[num].sel = K_CODE_SEGMENT;
-	idt_entries[num].always0 = 0;
-	idt_entries[num].type_attr = GATE_PRESENT
-				| (3 << GATE_DPL_SHIFT)		// accessible from user mode
-				| type;
-}
-
-static const struct {
-	uint8_t num;
-	void (*fun)();
-	uint8_t type;
-} gates[] = {
-	// Most processor exceptions are traps and handling them
-	// should be preemptible
-	{ 0,	isr0,	GATE_TYPE_TRAP },
-	{ 1,	isr1,	GATE_TYPE_TRAP },
-	{ 2,	isr2,	GATE_TYPE_TRAP },
-	{ 3,	isr3,	GATE_TYPE_TRAP },
-	{ 4,	isr4,	GATE_TYPE_TRAP },
-	{ 5,	isr5,	GATE_TYPE_TRAP },
-	{ 6,	isr6,	GATE_TYPE_TRAP },
-	{ 7,	isr7,	GATE_TYPE_TRAP },
-	{ 8,	isr8,	GATE_TYPE_TRAP },
-	{ 9,	isr9,	GATE_TYPE_TRAP },
-	{ 10,	isr10,	GATE_TYPE_TRAP },
-	{ 11,	isr11,	GATE_TYPE_TRAP },
-	{ 12,	isr12,	GATE_TYPE_TRAP },
-	{ 13,	isr13,	GATE_TYPE_TRAP },
-	{ 14,	isr14,	GATE_TYPE_INTERRUPT },	// reenables interrupts later on
-	{ 15,	isr15,	GATE_TYPE_TRAP },
-	{ 16,	isr16,	GATE_TYPE_TRAP },
-	{ 17,	isr17,	GATE_TYPE_TRAP },
-	{ 18,	isr18,	GATE_TYPE_TRAP },
-	{ 19,	isr19,	GATE_TYPE_TRAP },
-	{ 20,	isr20,	GATE_TYPE_TRAP },
-	{ 21,	isr21,	GATE_TYPE_TRAP },
-	{ 22,	isr22,	GATE_TYPE_TRAP },
-	{ 23,	isr23,	GATE_TYPE_TRAP },
-	{ 24,	isr24,	GATE_TYPE_TRAP },
-	{ 25,	isr25,	GATE_TYPE_TRAP },
-	{ 26,	isr26,	GATE_TYPE_TRAP },
-	{ 27,	isr27,	GATE_TYPE_TRAP },
-	{ 28,	isr28,	GATE_TYPE_TRAP },
-	{ 29,	isr29,	GATE_TYPE_TRAP },
-	{ 30,	isr30,	GATE_TYPE_TRAP },
-	{ 31,	isr31,	GATE_TYPE_TRAP },
-
-	// IRQs are not preemptible ; an IRQ handler should do the bare minimum
-	// (communication with the hardware), and then pass a message to a worker
-	// process in order to do further processing
-	{ 32,	irq0,	GATE_TYPE_INTERRUPT },
-	{ 33,	irq1,	GATE_TYPE_INTERRUPT },
-	{ 34,	irq2,	GATE_TYPE_INTERRUPT },
-	{ 35,	irq3,	GATE_TYPE_INTERRUPT },
-	{ 36,	irq4,	GATE_TYPE_INTERRUPT },
-	{ 37,	irq5,	GATE_TYPE_INTERRUPT },
-	{ 38,	irq6,	GATE_TYPE_INTERRUPT },
-	{ 39,	irq7,	GATE_TYPE_INTERRUPT },
-	{ 40,	irq8,	GATE_TYPE_INTERRUPT },
-	{ 41,	irq9,	GATE_TYPE_INTERRUPT },
-	{ 42,	irq10,	GATE_TYPE_INTERRUPT },
-	{ 43,	irq11,	GATE_TYPE_INTERRUPT },
-	{ 44,	irq12,	GATE_TYPE_INTERRUPT },
-	{ 45,	irq13,	GATE_TYPE_INTERRUPT },
-	{ 46,	irq14,	GATE_TYPE_INTERRUPT },
-	{ 47,	irq15,	GATE_TYPE_INTERRUPT },
-
-	// Of course, syscalls are preemptible
-	{ 64,	syscall64,	GATE_TYPE_TRAP },
-
-	{ 0, 0, 0 }
-};
-
-/*	Remaps the IRQs. Sets up the IDT. */
-void idt_init() {
-	memset((uint8_t*)&idt_entries, 0, sizeof(idt_entry_t) * 256);
-
-	//Remap the IRQ table
-	outb(0x20, 0x11);
-	outb(0xA0, 0x11);
-	outb(0x21, 0x20);
-	outb(0xA1, 0x28);
-	outb(0x21, 0x04);
-	outb(0xA1, 0x02);
-	outb(0x21, 0x01);
-	outb(0xA1, 0x01);
-	outb(0x21, 0x0);
-	outb(0xA1, 0x0);
-
-	for (int i = 0; gates[i].type != 0; i++) {
-		idt_set_gate(gates[i].num, gates[i].fun, gates[i].type);
-	}
-
-	idt_ptr.limit = (sizeof(idt_entry_t) * 256) - 1;
-	idt_ptr.base = (uint32_t)&idt_entries;
-
-	asm volatile ("lidt %0"::"m"(idt_ptr):"memory");
-	
-	// Some setup calls that come later on are not preemptible,
-	// so we wait until then to enable interrupts.
-}
-
-/*	Sets up an IRQ handler for given IRQ. */
-void idt_set_irq_handler(int number, isr_handler_t func) {
-	if (number < 16 && number >= 0) {
-		irq_handlers[number] = func;
-	}
-}
-
-/*	Sets up a handler for a processor exception */
-void idt_set_ex_handler(int number, isr_handler_t func) {
-	if (number >= 0 && number < 32) {
-		ex_handlers[number] = func;
-	}
-}
-
-void dbg_dump_registers(registers_t *regs) {
-	dbg_printf("/ Exception %i\n", regs->int_no);
-	dbg_printf("| EAX: 0x%p   EBX: 0x%p   ECX: 0x%p   EDX: 0x%p\n", regs->eax, regs->ebx, regs->ecx, regs->edx);
-	dbg_printf("| EDI: 0x%p   ESI: 0x%p   ESP: 0x%p   EBP: 0x%p\n", regs->edi, regs->esi, regs->esp, regs->ebp);
-	dbg_printf("| EIP: 0x%p   CS : 0x%p   DS : 0x%p   SS : 0x%p\n", regs->eip, regs->cs, regs->ds, regs->ss);
-	dbg_printf("\\ EFl: 0x%p   I# : 0x%p   Err: 0x%p\n", regs->eflags, regs->int_no, regs->err_code);
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
-
diff --git a/kernel/l0/interrupt.s b/kernel/l0/interrupt.s
deleted file mode 100644
index d40fff0..0000000
--- a/kernel/l0/interrupt.s
+++ /dev/null
@@ -1,126 +0,0 @@
-;************************************************************************************
-
-%macro COMMONSTUB 1
-[EXTERN idt_%1Handler]
-%1_common_stub:
-
-	pusha                    ; Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax
-
-	mov ax, ds               ; Lower 16-bits of eax = ds.
-	push eax                 ; save the data segment descriptor
-
-	mov ax, 0x10  ; load the kernel data segment descriptor
-	mov ds, ax
-	mov es, ax
-	mov fs, ax
-	mov gs, ax
-
-	; pass the register data structure as a pointer to the function
-	; (passing it directly results in GCC trashing the data when doing optimisations)
-	mov eax, esp
-	push eax
-	call idt_%1Handler
-	add esp, 4
-
-	pop eax        ; reload the original data segment descriptor
-	mov ds, ax
-	mov es, ax
-	mov fs, ax
-	mov gs, ax
-
-	popa                     ; Pops edi,esi,ebp...
-	add esp, 8     ; Cleans up the pushed error code and pushed ISR number
-	iret
-%endmacro
-
-COMMONSTUB ex
-COMMONSTUB irq
-COMMONSTUB syscall
-
-;************************************************************************************
-
-%macro EX_NOERRCODE 1  ; define a macro, taking one parameter
-	[GLOBAL isr%1]        ; %1 accesses the first parameter.
-	isr%1:
-		push byte 0
-		push byte %1
-		jmp ex_common_stub
-%endmacro
-
-%macro EX_ERRCODE 1
-	[GLOBAL isr%1]
-	isr%1:
-		push byte %1
-		jmp ex_common_stub
-%endmacro
-
-%macro IRQ 2
-	[GLOBAL irq%1]
-	irq%1:
-		push byte %1	;push irq number
-		push byte %2	;push int number
-		jmp irq_common_stub
-%endmacro
-
-%macro SYSCALL 1
-	[GLOBAL syscall%1]
-	syscall%1:
-		cli
-		push byte 0
-		push byte %1
-		jmp syscall_common_stub
-%endmacro
-
-EX_NOERRCODE 0
-EX_NOERRCODE 1
-EX_NOERRCODE 2
-EX_NOERRCODE 3
-EX_NOERRCODE 4
-EX_NOERRCODE 5
-EX_NOERRCODE 6
-EX_NOERRCODE 7
-EX_ERRCODE 8
-EX_NOERRCODE 9
-EX_ERRCODE 10
-EX_ERRCODE 11
-EX_ERRCODE 12
-EX_ERRCODE 13
-EX_ERRCODE 14
-EX_NOERRCODE 15
-EX_NOERRCODE 16
-EX_NOERRCODE 17
-EX_NOERRCODE 18
-EX_NOERRCODE 19
-EX_NOERRCODE 20
-EX_NOERRCODE 21
-EX_NOERRCODE 22
-EX_NOERRCODE 23
-EX_NOERRCODE 24
-EX_NOERRCODE 25
-EX_NOERRCODE 26
-EX_NOERRCODE 27
-EX_NOERRCODE 28
-EX_NOERRCODE 29
-EX_NOERRCODE 30
-EX_NOERRCODE 31
-
-IRQ	0,	32
-IRQ	1,	33
-IRQ	2,	34
-IRQ	3,	35
-IRQ	4,	36
-IRQ	5,	37
-IRQ	6,	38
-IRQ	7,	39
-IRQ	8,	40
-IRQ	9,	41
-IRQ	10,	42
-IRQ	11,	43
-IRQ	12,	44
-IRQ	13,	45
-IRQ	14,	46
-IRQ	15,	47
-
-SYSCALL 64
-
-; vim: set ts=4 sw=4 tw=0 noet :
diff --git a/kernel/l0/kmain.c b/kernel/l0/kmain.c
deleted file mode 100644
index 826fa14..0000000
--- a/kernel/l0/kmain.c
+++ /dev/null
@@ -1,214 +0,0 @@
-#include <multiboot.h>
-#include <config.h>
-#include <dbglog.h>
-#include <sys.h>
-
-#include <gdt.h>
-#include <idt.h>
-#include <frame.h>
-#include <paging.h>
-#include <region.h>
-#include <kmalloc.h>
-
-#include <thread.h>
-
-#include <slab_alloc.h>
-#include <hashtbl.h>
-
-extern const void k_end_addr;	// defined in linker script : 0xC0000000 plus kernel stuff
-
-void breakpoint_handler(registers_t *regs) {
-	dbg_printf("Breakpoint! (int3)\n");
-	BOCHS_BREAKPOINT;
-}
-
-void region_test1() {
-	void* p = region_alloc(0x1000, "Test region", 0);
-	dbg_printf("Allocated one-page region: 0x%p\n", p);
-	dbg_print_region_info();
-	void* q = region_alloc(0x1000, "Test region", 0);
-	dbg_printf("Allocated one-page region: 0x%p\n", q);
-	dbg_print_region_info();
-	void* r = region_alloc(0x2000, "Test region", 0);
-	dbg_printf("Allocated two-page region: 0x%p\n", r);
-	dbg_print_region_info();
-	void* s = region_alloc(0x10000, "Test region", 0);
-	dbg_printf("Allocated 16-page region: 0x%p\n", s);
-	dbg_print_region_info();
-	region_free(p);
-	dbg_printf("Freed region 0x%p\n", p);
-	dbg_print_region_info();
-	region_free(q);
-	dbg_printf("Freed region 0x%p\n", q);
-	dbg_print_region_info();
-	region_free(r);
-	dbg_printf("Freed region 0x%p\n", r);
-	dbg_print_region_info();
-	region_free(s);
-	dbg_printf("Freed region 0x%p\n", s);
-	dbg_print_region_info();
-}
-
-void region_test2() {
-	// allocate a big region and try to write into it
-	dbg_printf("Begin region test 2...");
-	const size_t n = 200;
-	void* p0 = region_alloc(n * PAGE_SIZE, "Test big region", default_allocator_pf_handler);
-	for (size_t i = 0; i < n; i++) {
-		uint32_t *x = (uint32_t*)(p0 + i * PAGE_SIZE);
-		x[0] = 12;
-		x[1] = (i * 20422) % 122;
-	}
-	// unmap memory
-	for (size_t i = 0; i < n; i++) {
-		void* p = p0 + i * PAGE_SIZE;
-		uint32_t *x = (uint32_t*)p;
-		ASSERT(x[1] == (i * 20422) % 122);
-
-		uint32_t f = pd_get_frame(p);
-		ASSERT(f != 0);
-		pd_unmap_page(p);
-		ASSERT(pd_get_frame(p) == 0);
-
-		frame_free(f, 1);
-	}
-	region_free(p0);
-	dbg_printf("OK\n");
-}
-
-void kmalloc_test(void* kernel_data_end) {
-	// Test kmalloc !
-	dbg_print_region_info();
-	dbg_printf("Begin kmalloc test...\n");
-	const int m = 200;
-	uint16_t** ptr = kmalloc(m * sizeof(uint32_t));
-	for (int i = 0; i < m; i++) {
-		size_t s = 1 << ((i * 7) % 11 + 2);
-		ptr[i] = (uint16_t*)kmalloc(s);
-		ASSERT((void*)ptr[i] >= kernel_data_end && (size_t)ptr[i] < 0xFFC00000);
-		*ptr[i] = ((i * 211) % 1024);
-	}
-	dbg_printf("Fully allocated.\n");
-	dbg_print_region_info();
-	for (int i = 0; i < m; i++) {
-		for (int j = i; j < m; j++) {
-			ASSERT(*ptr[j] == (j * 211) % 1024);
-		}
-		kfree(ptr[i]);
-	}
-	kfree(ptr);
-	dbg_printf("Kmalloc test OK.\n");
-	dbg_print_region_info();
-}
-
-void test_hashtbl_1() {
-	// hashtable test
-	hashtbl_t *ht = create_hashtbl(str_key_eq_fun, str_hash_fun, 0);
-	hashtbl_add(ht, "test1", "Hello, world [test1]");
-	hashtbl_add(ht, "test2", "Hello, world [test2]");
-	dbg_printf("ht[test1] = %s\n", hashtbl_find(ht, "test1"));
-	dbg_printf("ht[test] = %s\n", hashtbl_find(ht, "test"));
-	dbg_printf("ht[test2] = %s\n", hashtbl_find(ht, "test2"));
-	dbg_printf("adding test...\n");
-	hashtbl_add(ht, "test", "Forever alone");
-	dbg_printf("ht[test1] = %s\n", hashtbl_find(ht, "test1"));
-	dbg_printf("ht[test] = %s\n", hashtbl_find(ht, "test"));
-	dbg_printf("ht[test2] = %s\n", hashtbl_find(ht, "test2"));
-	dbg_printf("removing test1...\n");
-	hashtbl_remove(ht, "test1");
-	dbg_printf("ht[test1] = %s\n", hashtbl_find(ht, "test1"));
-	dbg_printf("ht[test] = %s\n", hashtbl_find(ht, "test"));
-	dbg_printf("ht[test2] = %s\n", hashtbl_find(ht, "test2"));
-	delete_hashtbl(ht);
-}
-
-void test_hashtbl_2() {
-	hashtbl_t *ht = create_hashtbl(id_key_eq_fun, id_hash_fun, 0);
-	hashtbl_add(ht, (void*)12, "Hello, world [12]");
-	hashtbl_add(ht, (void*)777, "Hello, world [777]");
-	dbg_printf("ht[12] = %s\n", hashtbl_find(ht, (void*)12));
-	dbg_printf("ht[144] = %s\n", hashtbl_find(ht, (void*)144));
-	dbg_printf("ht[777] = %s\n", hashtbl_find(ht, (void*)777));
-	dbg_printf("adding 144...\n");
-	hashtbl_add(ht, (void*)144, "Forever alone");
-	dbg_printf("ht[12] = %s\n", hashtbl_find(ht, (void*)12));
-	dbg_printf("ht[144] = %s\n", hashtbl_find(ht, (void*)144));
-	dbg_printf("ht[777] = %s\n", hashtbl_find(ht, (void*)777));
-	dbg_printf("removing 12...\n");
-	hashtbl_remove(ht, (void*)12);
-	dbg_printf("ht[12] = %s\n", hashtbl_find(ht, (void*)12));
-	dbg_printf("ht[144] = %s\n", hashtbl_find(ht, (void*)144));
-	dbg_printf("ht[777] = %s\n", hashtbl_find(ht, (void*)777));
-	delete_hashtbl(ht);
-}
-
-void test_thread(void* a) {
-	for(int i = 0; i < 120; i++) {
-		dbg_printf("b");
-		for (int x = 0; x < 100000; x++) asm volatile("xor %%ebx, %%ebx":::"%ebx");
-		if (i % 8 == 0) yield();
-	}
-}
-void kernel_init_stage2(void* data) {
-	dbg_print_region_info();
-	dbg_print_frame_stats();
-
-	test_hashtbl_1();
-	test_hashtbl_2();
-
-	thread_t *tb = new_thread(test_thread, 0);
-	resume_thread(tb, false);
-
-	for (int i = 0; i < 120; i++) {
-		dbg_printf("a");
-		for (int x = 0; x < 100000; x++) asm volatile("xor %%ebx, %%ebx":::"%ebx");
-	}
-	PANIC("Reached kmain end! Falling off the edge.");
-}
- 
-void kmain(struct multiboot_info_t *mbd, int32_t mb_magic) {
-	dbglog_setup();
-
-	dbg_printf("Hello, kernel world!\n");
-	dbg_printf("This is %s, version %s.\n", OS_NAME, OS_VERSION);
-
-	ASSERT(mb_magic == MULTIBOOT_BOOTLOADER_MAGIC);
-
-	gdt_init(); dbg_printf("GDT set up.\n");
-
-	idt_init(); dbg_printf("IDT set up.\n");
-	idt_set_ex_handler(EX_BREAKPOINT, breakpoint_handler);
-	asm volatile("int $0x3");	// test breakpoint
-
-	size_t total_ram = ((mbd->mem_upper + mbd->mem_lower) * 1024);
-	dbg_printf("Total ram: %d Kb\n", total_ram / 1024);
-
-	// used for allocation of data structures before malloc is set up
-	// a pointer to this pointer is passed to the functions that might have
-	// to allocate memory ; they just increment it of the allocated quantity
-	void* kernel_data_end = (void*)&k_end_addr;
-
-	frame_init_allocator(total_ram, &kernel_data_end);
-	dbg_printf("kernel_data_end: 0x%p\n", kernel_data_end);
-	dbg_print_frame_stats();
-
-	paging_setup(kernel_data_end);
-	dbg_printf("Paging seems to be working!\n");
-
-	BOCHS_BREAKPOINT;
-
-	region_allocator_init(kernel_data_end);
-	region_test1();
-	region_test2();
-
-	kmalloc_setup();
-	kmalloc_test(kernel_data_end);
-
-	// enter multi-threading mode
-	// interrupts are enabled at this moment, so all
-	// code run from now on should be preemtible (ie thread-safe)
-	threading_setup(kernel_init_stage2, 0);
-	PANIC("Should never come here.");
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/kmalloc.c b/kernel/l0/kmalloc.c
deleted file mode 100644
index e356ada..0000000
--- a/kernel/l0/kmalloc.c
+++ /dev/null
@@ -1,52 +0,0 @@
-#include <kmalloc.h>
-
-#include <slab_alloc.h>
-#include <mutex.h>
-
-#include <frame.h>
-#include <paging.h>
-#include <region.h>
-
-static void* page_alloc_fun_for_kmalloc(size_t bytes) {
-	void* addr = region_alloc(bytes, "Core kernel heap", default_allocator_pf_handler);
-	return addr;
-}
-
-static slab_type_t slab_sizes[] = {
-	{ "8B kmalloc objects", 8, 2 },
-	{ "16B kmalloc objects", 16, 2 },
-	{ "32B kmalloc objects", 32, 2 },
-	{ "64B kmalloc objects", 64, 4 },
-	{ "128B kmalloc objects", 128, 4 },
-	{ "256B kmalloc objects", 256, 4 },
-	{ "512B kmalloc objects", 512, 8 },
-	{ "1KB kmalloc objects", 1024, 8 },
-	{ "2KB kmalloc objects", 2048, 16 },
-	{ "4KB kmalloc objects", 4096, 16 },
-	{ 0, 0, 0 }
-};
-
-static mem_allocator_t *kernel_allocator = 0;
-STATIC_MUTEX(kmalloc_mutex);
-
-void kmalloc_setup() {
-	kernel_allocator =
-	  create_slab_allocator(slab_sizes, page_alloc_fun_for_kmalloc,
-										region_free_unmap_free);
-}
-
-void* kmalloc(size_t sz) {
-	void* res = 0;
-
-	mutex_lock(&kmalloc_mutex);
-	res = slab_alloc(kernel_allocator, sz);
-	mutex_unlock(&kmalloc_mutex);
-
-	return res;
-}
-
-void kfree(void* ptr) {
-	mutex_lock(&kmalloc_mutex);
-	slab_free(kernel_allocator, ptr);
-	mutex_unlock(&kmalloc_mutex);
-}
diff --git a/kernel/l0/loader.s b/kernel/l0/loader.s
deleted file mode 100644
index 447d82d..0000000
--- a/kernel/l0/loader.s
+++ /dev/null
@@ -1,86 +0,0 @@
-[EXTERN kmain]            ; kmain is defined in kmain.c
-[GLOBAL loader]           ; making entry point visible to linker
-[GLOBAL kernel_pd]   	  ; make kernel page directory visible
-[GLOBAL kernel_stack_protector] 		; used to detect kernel stack overflow
-[GLOBAL kernel_stack_top] 				; stack re-used by scheduler
-
-; higher-half kernel setup
-K_HIGHHALF_ADDR     equ 0xC0000000
-K_PAGE_NUMBER       equ (K_HIGHHALF_ADDR >> 22)
-
-; loader stack size
-LOADER_STACK_SIZE   equ 0x8000		; 8Kb
-
-; setting up the Multiboot header - see GRUB docs for details
-MODULEALIGN         equ 1<<0                   ; align loaded modules on page boundaries
-MEMINFO             equ 1<<1                   ; provide memory map
-FLAGS               equ MODULEALIGN | MEMINFO  ; this is the Multiboot 'flag' field
-MAGIC               equ 0x1BADB002           ; 'magic number' lets bootloader find the header
-CHECKSUM            equ -(MAGIC + FLAGS)        ; checksum required
-
-[section .setup]
-align 4
-multiboot_header:
-	dd MAGIC
-	dd FLAGS
-	dd CHECKSUM
-
-loader:	
-	; setup the boot page directory used for higher-half
-	mov ecx, kernel_pd
-	sub ecx, K_HIGHHALF_ADDR	; access its lower-half address
-	mov cr3, ecx
-
-	; Set PSE bit in CR4 to enable 4MB pages.
-	mov ecx, cr4
-	or ecx, 0x00000010
-	mov cr4, ecx
-
-	; Set PG bit in CR0 to enable paging.
-	mov ecx, cr0
-	or ecx, 0x80000000
-	mov cr0, ecx
-
-	; long jump required
-	lea ecx, [higherhalf]
-	jmp ecx
-
-[section .data]
-align 0x1000
-kernel_pd:
-	; uses 4MB pages
-	; identity-maps the first 4Mb of RAM, and also maps them with offset += k_highhalf_addr
-	dd 0x00000083
-	times (K_PAGE_NUMBER - 1) dd 0
-	dd 0x00000083
-	times (1024 - K_PAGE_NUMBER - 1) dd 0
-
-[section .text]
-higherhalf:		; now we're running in higher half
-	; unmap first 4Mb
-	mov dword [kernel_pd], 0
-	invlpg [0]
-
-	mov esp, kernel_stack_top   ; set up the stack
-
-	push eax                    ; pass Multiboot magic number
-	add ebx, K_HIGHHALF_ADDR    ; update the MB info structure so that it is in higher half
-	push ebx                    ; pass Multiboot info structure
-
-	call  kmain                 ; call kernel proper
-
-hang:
-	; halt machine should kernel return
-	cli
-	hlt
-	jmp   hang
-
-[section .bss]
-align 0x1000
-kernel_stack_protector:
-	resb 0x1000			; as soon as we have efficient paging, we WON'T map this page
-kernel_stack_bottom:
-	resb LOADER_STACK_SIZE
-kernel_stack_top:
-
-; vim: set ts=4 sw=4 tw=0 noet :
diff --git a/kernel/l0/paging.c b/kernel/l0/paging.c
deleted file mode 100644
index 683abe6..0000000
--- a/kernel/l0/paging.c
+++ /dev/null
@@ -1,298 +0,0 @@
-#include <paging.h>
-#include <frame.h>
-#include <idt.h>
-#include <dbglog.h>
-#include <region.h>
-#include <mutex.h>
-#include <thread.h>
-#include <kmalloc.h>
-
-#define PAGE_OF_ADDR(x)		(((size_t)x >> PAGE_SHIFT) % N_PAGES_IN_PT)
-#define PT_OF_ADDR(x)		((size_t)x >> (PAGE_SHIFT + PT_SHIFT))
-
-#define PTE_PRESENT			(1<<0)
-#define PTE_RW				(1<<1)
-#define PTE_USER			(1<<2)
-#define PTE_WRITE_THROUGH	(1<<3)
-#define PTE_DISABLE_CACHE	(1<<4)
-#define PTE_ACCESSED		(1<<5)
-#define PTE_DIRTY			(1<<6)		// only PTE
-#define PTE_SIZE_4M			(1<<7)		// only PDE
-#define PTE_GLOBAL			(1<<8)		// only PTE
-#define PTE_FRAME_SHIFT		12
-
-typedef struct page_table {
-	uint32_t page[1024];
-} pagetable_t;
-
-struct page_directory {
-	uint32_t phys_addr;		// physical address of page directory
-	// to modify a page directory, we first map it
-	// then we can use mirroring to edit it
-	// (the last 4M of the address space are mapped to the PD itself)
-
-	mutex_t mutex;
-};
-
-
-// access kernel page directory page defined in loader.s
-// (this is a correct higher-half address)
-extern pagetable_t kernel_pd;
-
-// pre-allocate a page table so that we can map the first 4M of kernel memory
-static pagetable_t __attribute__((aligned(PAGE_SIZE))) kernel_pt0;
-
-extern char kernel_stack_protector;
-
-static pagedir_t kernel_pd_d;
-
-#define current_pt ((pagetable_t*)PD_MIRROR_ADDR)
-#define current_pd ((pagetable_t*)(PD_MIRROR_ADDR + (N_PAGES_IN_PT-1)*PAGE_SIZE))
-
-void page_fault_handler(registers_t *regs) {
-	void* vaddr;
-	asm volatile("movl %%cr2, %0":"=r"(vaddr));
-
-	if ((size_t)vaddr >= K_HIGHHALF_ADDR) {
-		uint32_t pt = PT_OF_ADDR(vaddr);
-
-		if (current_pd != &kernel_pd && current_pd->page[pt] != kernel_pd.page[pt]) {
-			current_pd->page[pt] = kernel_pd.page[pt];
-			invlpg(&current_pt[pt]);
-			return;
-		}
-		if (regs->eflags & EFLAGS_IF) asm volatile("sti");	// from now on we are preemptible
-
-		if (vaddr >= (void*)&kernel_stack_protector && vaddr < (void*)&kernel_stack_protector + PAGE_SIZE) {
-			dbg_printf("Kernel stack overflow at 0x%p\n", vaddr);
-			PANIC("Kernel stack overflow.");
-		}
-
-		if ((size_t)vaddr >= PD_MIRROR_ADDR) {
-			dbg_printf("Fault on access to mirrorred PD at 0x%p\n", vaddr);
-			dbg_print_region_info();
-			PANIC("Unhandled kernel space page fault");
-		}
-
-		region_info_t *i = find_region(vaddr);
-		if (i == 0) {
-			dbg_printf("Kernel pagefault in non-existing region at 0x%p\n", vaddr);
-			dbg_dump_registers(regs);
-			PANIC("Unhandled kernel space page fault");
-		}
-		if (i->pf == 0) {
-			dbg_printf("Kernel pagefault in region with no handler at 0x%p\n", vaddr);
-			dbg_dump_registers(regs);
-			dbg_print_region_info();
-			PANIC("Unhandled kernel space page fault");
-		}
-		i->pf(get_current_pagedir(), i, vaddr);
-	} else {
-		if (regs->eflags & EFLAGS_IF) asm volatile("sti");	// userspace PF handlers should always be preemptible
-
-		dbg_printf("Userspace page fault at 0x%p\n", vaddr);
-		PANIC("Unhandled userspace page fault");
-		// not handled yet
-		// TODO
-	}
-}
-
-void paging_setup(void* kernel_data_end) {
-	size_t n_kernel_pages =
-		PAGE_ALIGN_UP((size_t)kernel_data_end - K_HIGHHALF_ADDR)/PAGE_SIZE;
-
-	ASSERT(n_kernel_pages <= 1024);	// we use less than 4M for kernel
-
-	// setup kernel_pd_d structure
-	kernel_pd_d.phys_addr = (size_t)&kernel_pd - K_HIGHHALF_ADDR;
-	kernel_pd_d.mutex = MUTEX_UNLOCKED;
-
-	// setup kernel_pt0
-	ASSERT(PAGE_OF_ADDR(K_HIGHHALF_ADDR) == 0);	// kernel is 4M-aligned
-	ASSERT(FIRST_KERNEL_PT == 768);
-	for (size_t i = 0; i < n_kernel_pages; i++) {
-		if ((i * PAGE_SIZE) + K_HIGHHALF_ADDR == (size_t)&kernel_stack_protector) {
-			kernel_pt0.page[i] = 0;	// don't map kernel stack protector page
-			frame_free(i, 1);
-		} else {
-			kernel_pt0.page[i] = (i << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW | PTE_GLOBAL;
-		}
-	}
-	for (size_t i = n_kernel_pages; i < 1024; i++){
-		kernel_pt0.page[i] = 0;
-	}
-
-	// replace 4M mapping by kernel_pt0
-	kernel_pd.page[FIRST_KERNEL_PT] =
-		(((size_t)&kernel_pt0 - K_HIGHHALF_ADDR) & PAGE_MASK) | PTE_PRESENT | PTE_RW;
-	// set up mirroring
-	kernel_pd.page[N_PAGES_IN_PT-1] =
-		(((size_t)&kernel_pd - K_HIGHHALF_ADDR) & PAGE_MASK) | PTE_PRESENT | PTE_RW;
-
-	invlpg((void*)K_HIGHHALF_ADDR);
-
-	// paging already enabled in loader, nothing to do.
-
-	// disable 4M pages (remove PSE bit in CR4)
-	uint32_t cr4;
-	asm volatile("movl %%cr4, %0": "=r"(cr4));
-	cr4 &= ~0x00000010;
-	asm volatile("movl %0, %%cr4":: "r"(cr4));
-
-	idt_set_ex_handler(EX_PAGE_FAULT, page_fault_handler);
-}
-
-pagedir_t *get_current_pagedir() {
-	if (current_thread == 0) return &kernel_pd_d;
-	return current_thread->current_pd_d;
-}
-
-pagedir_t *get_kernel_pagedir() {
-	return &kernel_pd_d;
-}
-
-void switch_pagedir(pagedir_t *pd) {
-	asm volatile("movl %0, %%cr3":: "r"(pd->phys_addr));
-	if (current_thread != 0) current_thread->current_pd_d = pd;
-}
-
-// ============================== //
-// Mapping and unmapping of pages //
-// ============================== //
-
-uint32_t pd_get_frame(void* vaddr) {
-	uint32_t pt = PT_OF_ADDR(vaddr);
-	uint32_t page = PAGE_OF_ADDR(vaddr);
-
-	pagetable_t *pd = ((size_t)vaddr >= K_HIGHHALF_ADDR ? &kernel_pd : current_pd);
-
-	if (!pd->page[pt] & PTE_PRESENT) return 0;
-	if (!current_pt[pt].page[page] & PTE_PRESENT) return 0;
-	return current_pt[pt].page[page] >> PTE_FRAME_SHIFT;
-}
-
-int pd_map_page(void* vaddr, uint32_t frame_id, bool rw) {
-	uint32_t pt = PT_OF_ADDR(vaddr);
-	uint32_t page = PAGE_OF_ADDR(vaddr);
-
-	ASSERT((size_t)vaddr < PD_MIRROR_ADDR);
-	
-	pagedir_t *pdd = ((size_t)vaddr >= K_HIGHHALF_ADDR || current_thread == 0
-							? &kernel_pd_d : current_thread->current_pd_d);
-	pagetable_t *pd = ((size_t)vaddr >= K_HIGHHALF_ADDR ? &kernel_pd : current_pd);
-	mutex_lock(&pdd->mutex);
-
-	if (!pd->page[pt] & PTE_PRESENT) {
-		uint32_t new_pt_frame = frame_alloc(1);
-		if (new_pt_frame == 0) {
-			mutex_unlock(&pdd->mutex);
-			return 1;	// OOM
-		}
-
-		current_pd->page[pt] = pd->page[pt] =
-			(new_pt_frame << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW;
-		invlpg(&current_pt[pt]);
-	}
-	current_pt[pt].page[page] =
-		(frame_id << PTE_FRAME_SHIFT)
-			| PTE_PRESENT
-			| ((size_t)vaddr < K_HIGHHALF_ADDR ? PTE_USER : PTE_GLOBAL)
-			| (rw ? PTE_RW : 0);
-	invlpg(vaddr);
-
-	mutex_unlock(&pdd->mutex);
-	return 0;
-} 
-
-void pd_unmap_page(void* vaddr) {
-	uint32_t pt = PT_OF_ADDR(vaddr);
-	uint32_t page = PAGE_OF_ADDR(vaddr);
-
-	pagetable_t *pd = ((size_t)vaddr >= K_HIGHHALF_ADDR ? &kernel_pd : current_pd);
-	// no need to lock the PD's mutex
-
-	if (!pd->page[pt] & PTE_PRESENT) return;
-	if (!current_pt[pt].page[page] & PTE_PRESENT) return;
-
-	current_pt[pt].page[page] = 0;
-	invlpg(vaddr);
-
-	// If the page table is completely empty we might want to free
-	// it, but we would actually lose a lot of time checking if
-	// the PT is really empty (since we don't store the
-	// number of used pages in each PT), so it's probably not worth it
-}
-
-// Creation and deletion of page directories
-
-pagedir_t *create_pagedir() {
-	uint32_t pd_phys = 0;
-	pagedir_t *pd = 0;
-	void* temp = 0;
-
-	pd_phys = frame_alloc(1);
-	if (pd_phys == 0) goto error;
-
-	pd = (pagedir_t*)kmalloc(sizeof(pagedir_t));
-	if (pd == 0) goto error;
-
-	temp = region_alloc(PAGE_SIZE, 0, 0);
-	if (temp == 0) goto error;
-
-	int error = pd_map_page(temp, pd_phys, true);
-	if (error) goto error;
-
-	pd->phys_addr = pd_phys * PAGE_SIZE;
-	pd->mutex = MUTEX_UNLOCKED;
-
-	// initialize PD with zeroes
-	pagetable_t *pt = (pagetable_t*)temp;
-	for (size_t i = 0; i < N_PAGES_IN_PT; i++) {
-		pt->page[i] = 0;
-	}
-	// use kernel page tables
-	for(size_t i = FIRST_KERNEL_PT; i < N_PAGES_IN_PT-1; i++) {
-		pt->page[i] = kernel_pd.page[i];
-	}
-	// set up mirroring
-	pt->page[N_PAGES_IN_PT-1] = pd->phys_addr | PTE_PRESENT | PTE_RW;
-
-	region_free_unmap(temp);
-
-	return pd;
-
-	error:
-	if (pd_phys != 0) frame_free(pd_phys, 1);
-	if (pd != 0) kfree(pd);
-	if (temp != 0) region_free(temp);
-	return 0;
-}
-
-void delete_pagedir(pagedir_t *pd) {
-	pagedir_t *restore_pd = get_current_pagedir();
-	if (restore_pd == pd) restore_pd = &kernel_pd_d;
-
-	// make a copy of page directory on the stack
-	switch_pagedir(pd);
-	pagetable_t backup;
-	for (size_t i = 0; i < N_PAGES_IN_PT; i++) {
-		backup.page[i] = current_pd->page[i];
-	}
-	switch_pagedir(restore_pd);
-	
-	// free the page tables
-	for (size_t i = 0; i < FIRST_KERNEL_PT; i++) {
-		if (backup.page[i] & PTE_PRESENT)
-			frame_free(backup.page[i] >> PTE_FRAME_SHIFT, 1);
-	}
-	// free the page directory page
-	uint32_t pd_phys = pd->phys_addr / PAGE_SIZE;
-	ASSERT(pd_phys == (backup.page[N_PAGES_IN_PT-1] >> PTE_FRAME_SHIFT));
-	frame_free(pd_phys, 1);
-	// free the pagedir_t structure
-	kfree(pd);
-
-	return;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/region.c b/kernel/l0/region.c
deleted file mode 100644
index 3127048..0000000
--- a/kernel/l0/region.c
+++ /dev/null
@@ -1,397 +0,0 @@
-#include <region.h>
-#include <dbglog.h>
-#include <frame.h>
-#include <mutex.h>
-
-typedef union region_descriptor {
-	struct {
-		union region_descriptor *next;
-	} unused_descriptor;
-	struct {
-		void* addr;
-		size_t size;
-		union region_descriptor *next_by_size, *first_bigger;
-		union region_descriptor *next_by_addr;
-	} free;
-	struct {
-		region_info_t i;
-		union region_descriptor *next_by_addr;
-	} used;
-} descriptor_t;
-
-#define N_RESERVE_DESCRIPTORS 2		// always keep at least 2 unused descriptors
-
-#define N_BASE_DESCRIPTORS 12		// pre-allocate memory for 12 descriptors
-static descriptor_t base_descriptors[N_BASE_DESCRIPTORS];
-
-static descriptor_t *first_unused_descriptor; 
-uint32_t n_unused_descriptors;
-static descriptor_t *first_free_region_by_addr, *first_free_region_by_size;
-static descriptor_t *first_used_region;
-
-STATIC_MUTEX(ra_mutex);	// region allocator mutex
-
-// ========================================================= //
-// HELPER FUNCTIONS FOR THE MANIPULATION OF THE REGION LISTS //
-// ========================================================= //
-
-static void add_unused_descriptor(descriptor_t *d) {
-	n_unused_descriptors++;
-	d->unused_descriptor.next = first_unused_descriptor;
-	first_unused_descriptor = d;
-}
-
-static descriptor_t *get_unused_descriptor() {
-	descriptor_t *r = first_unused_descriptor;
-	if (r != 0) {
-		first_unused_descriptor = r->unused_descriptor.next;
-		n_unused_descriptors--;
-	}
-	return r;
-}
-
-static void remove_free_region(descriptor_t *d) {
-	if (first_free_region_by_size == d) {
-		first_free_region_by_size = d->free.next_by_size;
-	} else {
-		for (descriptor_t *i = first_free_region_by_size; i != 0; i = i->free.next_by_size) {
-			if (i->free.next_by_size == d) {
-				i->free.next_by_size = d->free.next_by_size;
-				break;
-			}
-		}
-	}
-	if (first_free_region_by_addr == d) {
-		first_free_region_by_addr = d->free.next_by_addr;
-	} else {
-		for (descriptor_t *i = first_free_region_by_addr; i != 0; i = i->free.next_by_addr) {
-			if (i->free.next_by_addr == d) {
-				i->free.next_by_addr = d->free.next_by_addr;
-				break;
-			}
-		}
-	}
-}
-
-static void add_free_region(descriptor_t *d) {
-	/*dbg_printf("Add free region 0x%p - 0x%p\n", d->free.addr, d->free.size + d->free.addr);*/
-	// Find position of region in address-ordered list
-	// Possibly concatenate free region
-	descriptor_t *i = first_free_region_by_addr;
-	if (i == 0) {
-		ASSERT(first_free_region_by_size == 0);
-		first_free_region_by_addr = first_free_region_by_size = d;
-		d->free.next_by_size = d->free.first_bigger = d->free.next_by_addr = 0;
-		return;
-	} else if (d->free.addr + d->free.size == i->free.addr) {
-		// concatenate d . i
-		remove_free_region(i);
-		d->free.size += i->free.size;
-		add_unused_descriptor(i);
-		add_free_region(d);
-		return;
-	} else if (i->free.addr > d->free.addr) {
-		// insert before i
-		d->free.next_by_addr = i;
-		first_free_region_by_addr = d;
-	} else {
-		while (i != 0) {
-			ASSERT(d->free.addr > i->free.addr);
-			if (i->free.addr + i->free.size == d->free.addr) {
-				// concatenate i . d
-				remove_free_region(i);
-				i->free.size += d->free.size;
-				add_unused_descriptor(d);
-				add_free_region(i);
-				return;
-			} else if (i->free.next_by_addr == 0 || i->free.next_by_addr->free.addr > d->free.addr) {
-				d->free.next_by_addr = i->free.next_by_addr;
-				i->free.next_by_addr = d;
-				break;
-			} else if (d->free.addr + d->free.size == i->free.next_by_addr->free.addr) {
-				// concatenate d . i->next_by_addr
-				descriptor_t *j = i->free.next_by_addr;
-				remove_free_region(j);
-				d->free.size += j->free.size;
-				add_unused_descriptor(j);
-				add_free_region(d);
-				return;
-			} else {
-				// continue
-				i = i->free.next_by_addr;
-			}
-		}
-	}
-	// Now add it in size-ordered list
-	i = first_free_region_by_size;
-	ASSERT(i != 0);
-	if (d->free.size <= i->free.size) {
-		d->free.next_by_size = i;
-		d->free.first_bigger = (i->free.size > d->free.size ? i : i->free.first_bigger);
-		first_free_region_by_size = d;
-	} else {
-		while (i != 0) {
-			ASSERT(d->free.size > i->free.size);
-			if (i->free.next_by_size == 0) {
-				d->free.next_by_size = 0;
-				d->free.first_bigger = 0;
-				i->free.next_by_size = d;
-				if (d->free.size > i->free.size) i->free.first_bigger = d;
-				break;
-			} else if (i->free.next_by_size->free.size >= d->free.size) {
-				d->free.next_by_size = i->free.next_by_size;
-				d->free.first_bigger =
-					(i->free.next_by_size->free.size > d->free.size
-						? i->free.next_by_size
-						: i->free.next_by_size->free.first_bigger);
-				i->free.next_by_size = d;
-				if (d->free.size > i->free.size) i->free.first_bigger = d;
-				break;
-			} else {
-				// continue
-				i = i->free.next_by_size;
-			}
-		}
-	}
-}
-
-static descriptor_t *find_used_region(void* addr) {
-	for (descriptor_t *i = first_used_region; i != 0; i = i->used.next_by_addr) {
-		if (addr >= i->used.i.addr && addr < i->used.i.addr + i->used.i.size) return i;
-		if (i->used.i.addr > addr) break;
-	}
-	return 0;
-}
-
-static void add_used_region(descriptor_t *d) {
-	descriptor_t *i = first_used_region;
-	ASSERT(i->used.i.addr < d->used.i.addr);	// first region by address is never free
-
-	while (i != 0) {
-		ASSERT(i->used.i.addr < d->used.i.addr);
-		if (i->used.next_by_addr == 0 || i->used.next_by_addr->used.i.addr > d->used.i.addr) {
-			d->used.next_by_addr = i->used.next_by_addr;
-			i->used.next_by_addr = d;
-			return;
-		} else {
-			i = i->used.next_by_addr;
-		}
-	}
-	ASSERT(false);
-}
-
-static void remove_used_region(descriptor_t *d) {
-	if (first_used_region == d) {
-		first_used_region = d->used.next_by_addr;
-	} else {
-		for (descriptor_t *i = first_used_region; i != 0; i = i->used.next_by_addr) {
-			if (i->used.i.addr > d->used.i.addr) break;
-			if (i->used.next_by_addr == d) {
-				i->used.next_by_addr = d->used.next_by_addr;
-				break;
-			}
-		}
-	}
-}
-
-// =============== //
-// THE ACTUAL CODE //
-// =============== //
-
-void region_allocator_init(void* kernel_data_end) {
-	n_unused_descriptors = 0;
-	first_unused_descriptor = 0;
-	for (int i = 0; i < N_BASE_DESCRIPTORS; i++) {
-		add_unused_descriptor(&base_descriptors[i]);
-	}
-
-	descriptor_t *f0 = get_unused_descriptor();
-	f0->free.addr = (void*)PAGE_ALIGN_UP(kernel_data_end);
-	f0->free.size = ((void*)LAST_KERNEL_ADDR - f0->free.addr);
-	f0->free.next_by_size = 0;
-	f0->free.first_bigger = 0;
-	first_free_region_by_size = first_free_region_by_addr = f0;
-
-	descriptor_t *u0 = get_unused_descriptor();
-	u0->used.i.addr = (void*)K_HIGHHALF_ADDR;
-	u0->used.i.size = PAGE_ALIGN_UP(kernel_data_end) - K_HIGHHALF_ADDR;
-	u0->used.i.type = "Kernel code & data";
-	u0->used.i.pf = 0;
-	u0->used.next_by_addr = 0;
-	first_used_region = u0;
-}
-
-static void region_free_inner(void* addr) {
-	descriptor_t *d = find_used_region(addr);
-	if (d == 0) return;
-
-	region_info_t i = d->used.i;
-
-	remove_used_region(d);
-	d->free.addr = i.addr;
-	d->free.size = i.size;
-	add_free_region(d);
-}
-void region_free(void* addr) {
-	mutex_lock(&ra_mutex);
-	region_free_inner(addr);
-	mutex_unlock(&ra_mutex);
-}
-
-static void* region_alloc_inner(size_t size, char* type, page_fault_handler_t pf, bool use_reserve) {
-	size = PAGE_ALIGN_UP(size);
-
-	for (descriptor_t *i = first_free_region_by_size; i != 0; i = i->free.first_bigger) {
-		if (i->free.size >= size) {
-			// region i is the one we want to allocate in
-			descriptor_t *x = 0;
-			if (i->free.size > size) {
-				if (n_unused_descriptors <= N_RESERVE_DESCRIPTORS && !use_reserve) {
-					return 0;
-				}
-
-				// this assert basically means that the allocation function
-				// is called less than N_RESERVE_DESCRIPTORS times with
-				// the use_reserve flag before more descriptors
-				// are allocated.
-				x = get_unused_descriptor();
-				ASSERT(x != 0);
-
-				x->free.size = i->free.size - size;
-				if (size >= 0x4000) {
-					x->free.addr = i->free.addr + size;
-				} else {
-					x->free.addr = i->free.addr;
-					i->free.addr += x->free.size;
-				}
-			}
-			// do the allocation
-			remove_free_region(i);
-			if (x != 0) add_free_region(x);
-
-			void* addr = i->free.addr;
-			i->used.i.addr = addr;
-			i->used.i.size = size;
-			i->used.i.type = type;
-			i->used.i.pf = pf;
-			add_used_region(i);
-
-			return addr;
-		}
-	}
-	return 0;	//No big enough block found
-}
-
-void* region_alloc(size_t size, char* type, page_fault_handler_t pf) {
-	void* result = 0;
-	mutex_lock(&ra_mutex);
-
-	if (n_unused_descriptors <= N_RESERVE_DESCRIPTORS) {
-		uint32_t frame = frame_alloc(1);
-		if (frame == 0) goto try_anyway;
-
-		void* descriptor_region = region_alloc_inner(PAGE_SIZE, "Region descriptors", 0, true);
-		ASSERT(descriptor_region != 0);
-
-		int error = pd_map_page(descriptor_region, frame, 1);
-		if (error) {
-			// this can happen if we weren't able to allocate a frame for
-			// a new pagetable
-			frame_free(frame, 1);
-			region_free_inner(descriptor_region);
-			goto try_anyway;
-		}
-		
-		for (descriptor_t *d = (descriptor_t*)descriptor_region;
-				(void*)(d+1) <= (descriptor_region + PAGE_SIZE);
-				d++) {
-			add_unused_descriptor(d);
-		}
-	}
-	try_anyway:
-	// even if we don't have enough unused descriptors, we might find
-	// a free region that has exactly the right size and therefore
-	// does not require splitting, so we try the allocation in all cases
-	result = region_alloc_inner(size, type, pf, false);
-
-	mutex_unlock(&ra_mutex);
-	return result;
-}
-
-region_info_t *find_region(void* addr) {
-	region_info_t *r = 0;
-	mutex_lock(&ra_mutex);
-
-	descriptor_t *d = find_used_region(addr);
-	if (d != 0) r = &d->used.i;
-
-	mutex_unlock(&ra_mutex);
-	return r;
-}
-
-// ========================================================= //
-// HELPER FUNCTIONS : SIMPLE PF HANDLERS ; FREEING FUNCTIONS //
-// ========================================================= //
-
-void default_allocator_pf_handler(pagedir_t *pd, struct region_info *r, void* addr) {
-	ASSERT(pd_get_frame(addr) == 0);	// if error is of another type (RO, protected), we don't do anyting
-
-	uint32_t f = frame_alloc(1);
-	if (f == 0) PANIC("Out Of Memory");
-
-	int error = pd_map_page(addr, f, 1);
-	if (error) PANIC("Could not map frame (OOM)");
-}
-
-void region_free_unmap_free(void* ptr) {
-	region_info_t *i = find_region(ptr);
-	ASSERT(i != 0);
-
-	for (void* x = i->addr; x < i->addr + i->size; x += PAGE_SIZE) {
-		uint32_t f = pd_get_frame(x);
-		if (f != 0) {
-			pd_unmap_page(x);
-			frame_free(f, 1);
-		}
-	}
-	region_free(ptr);
-}
-
-void region_free_unmap(void* ptr) {
-	region_info_t *i = find_region(ptr);
-	ASSERT(i != 0);
-
-	for (void* x = i->addr; x < i->addr + i->size; x += PAGE_SIZE) {
-		pd_unmap_page(x);
-	}
-	region_free(ptr);
-}
-
-// =========================== //
-// DEBUG LOG PRINTING FUNCTION //
-// =========================== //
-
-void dbg_print_region_info() {
-	mutex_lock(&ra_mutex);
-
-	dbg_printf("/ Free kernel regions, by address:\n");
-	for (descriptor_t *d = first_free_region_by_addr; d != 0; d = d->free.next_by_addr) {
-		dbg_printf("| 0x%p - 0x%p\n", d->free.addr, d->free.addr + d->free.size);
-		ASSERT(d != d->free.next_by_addr);
-	}
-	dbg_printf("- Free kernel regions, by size:\n");
-	for (descriptor_t *d = first_free_region_by_size; d != 0; d = d->free.next_by_size) {
-		dbg_printf("| 0x%p - 0x%p\n", d->free.addr, d->free.addr + d->free.size);
-		ASSERT(d != d->free.next_by_size);
-	}
-	dbg_printf("- Used kernel regions:\n");
-	for (descriptor_t *d = first_used_region; d != 0; d = d->used.next_by_addr) {
-		dbg_printf("| 0x%p - 0x%p  %s\n", d->used.i.addr, d->used.i.addr + d->used.i.size, d->used.i.type);
-		ASSERT(d != d->used.next_by_addr);
-	}
-	dbg_printf("\\\n");
-
-	mutex_unlock(&ra_mutex);
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/sys.c b/kernel/l0/sys.c
deleted file mode 100644
index 2b77463..0000000
--- a/kernel/l0/sys.c
+++ /dev/null
@@ -1,25 +0,0 @@
-#include <sys.h>
-#include <dbglog.h>
-
-
-// Kernel panic and kernel assert failure
-
-static void panic_do(const char* type, const char *msg, const char* file, int line) {
-	asm volatile("cli;");
-	dbg_printf("/\n| %s:\t%s\n", type, msg);
-	dbg_printf("| File: \t%s:%i\n", file, line);
-	dbg_printf("| System halted -_-'\n");
-	dbg_printf("\\---------------------------------------------------------/");
-	BOCHS_BREAKPOINT;
-	asm volatile("hlt");
-}
-
-void panic(const char* message, const char* file, int line) {
-	panic_do("PANIC", message, file, line);
-}
-
-void panic_assert(const char* assertion, const char* file, int line) {
-	panic_do("ASSERT FAILED", assertion, file, line);
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/l0/thread.c b/kernel/l0/thread.c
deleted file mode 100644
index 0f5c209..0000000
--- a/kernel/l0/thread.c
+++ /dev/null
@@ -1,208 +0,0 @@
-#include <thread.h>
-#include <kmalloc.h>
-#include <dbglog.h>
-#include <idt.h>
-
-#include <frame.h>
-#include <paging.h>
-
-void save_context_and_enter_scheduler(saved_context_t *ctx);
-void irq0_save_context_and_enter_scheduler(saved_context_t *ctx);
-void resume_context(saved_context_t *ctx);
-
-thread_t *current_thread = 0;
-
-// ====================== //
-// THE PROGRAMMABLE TIMER //
-// ====================== //
-
-void set_pit_frequency(uint32_t freq) {
-   uint32_t divisor = 1193180 / freq;
-   ASSERT(divisor < 65536);	// must fit on 16 bits
-
-   uint8_t l = (divisor & 0xFF);
-   uint8_t h = ((divisor >> 8) & 0xFF);
-
-   outb(0x43, 0x36);
-   outb(0x40, l);
-   outb(0x40, h);
-}
-
-// ============================= //
-// HELPER : IF FLAG MANIPULATION //
-// ============================= //
-
-static inline bool disable_interrupts() {
-	uint32_t eflags;
-	asm volatile("pushf; pop %0" : "=r"(eflags));
-	asm volatile("cli");
-	return (eflags & EFLAGS_IF) != 0;
-}
-
-static inline void resume_interrupts(bool st) {
-	if (st) asm volatile("sti");
-}
-
-// ================== //
-// THE TASK SCHEDULER //
-// ================== //
-
-static thread_t *queue_first_thread = 0, *queue_last_thread = 0;
-
-void enqueue_thread(thread_t *t, bool just_ran) {
-	ASSERT(t->state == T_STATE_RUNNING);
-	if (queue_first_thread == 0) {
-		queue_first_thread = queue_last_thread = t;
-		t->next_in_queue = 0;
-	} else if (just_ran) {
-		t->next_in_queue = 0;
-		queue_last_thread->next_in_queue = t;
-		queue_last_thread = t;
-	} else {
-		t->next_in_queue = queue_first_thread;
-		queue_first_thread = t;
-	}
-}
-
-thread_t* dequeue_thread() {
-	thread_t *t = queue_first_thread;
-	if (t == 0) return 0;
-
-	queue_first_thread = t->next_in_queue;
-	if (queue_first_thread == 0) queue_last_thread = 0;
-
-	return t;
-}
-
-// ================ //
-// THE TASKING CODE //
-// ================ //
-
-void run_scheduler() {
-	// At this point, interrupts are disabled
-	// This function is expected NEVER TO RETURN
-
-	if (current_thread != 0 && current_thread->state == T_STATE_RUNNING) {
-		enqueue_thread(current_thread, true);
-	}
-
-	current_thread = dequeue_thread();
-	if (current_thread != 0) {
-		resume_context(&current_thread->ctx);
-	} else {
-		// Wait for an IRQ
-		asm volatile("sti; hlt");
-		// At this point an IRQ has happenned
-		// and has been processed. Loop around. 
-		run_scheduler();
-		ASSERT(false);
-	}
-}
-
-static void run_thread(void (*entry)(void*), void* data) {
-	ASSERT(current_thread->state == T_STATE_RUNNING);
-
-	switch_pagedir(get_kernel_pagedir());
-
-	asm volatile("sti");
-	entry(data);
-
-	current_thread->state = T_STATE_FINISHED;
-	// TODO : add job for deleting the thread, or whatever
-	yield();	// expected never to return!
-	ASSERT(false);
-}
-thread_t *new_thread(entry_t entry, void* data) {
-	thread_t *t = (thread_t*)kmalloc(sizeof(thread_t));
-	if (t == 0) return 0;
-
-	void* stack = region_alloc(KPROC_STACK_SIZE, "Stack", 0);
-	if (stack == 0) {
-		kfree(t);
-		return 0;
-	}
-
-	for (void* i = stack + PAGE_SIZE; i < stack + KPROC_STACK_SIZE; i += PAGE_SIZE) {
-		uint32_t f = frame_alloc(1);
-		if (f == 0) {
-			region_free_unmap_free(stack);
-			kfree(t);
-			return 0;
-		}
-		pd_map_page(i, f, true);
-	}
-
-	t->stack_region = find_region(stack);
-
-	t->ctx.esp = (uint32_t*)(t->stack_region->addr + t->stack_region->size);
-	*(--t->ctx.esp) = (uint32_t)data;	// push second argument : data
-	*(--t->ctx.esp) = (uint32_t)entry;	// push first argument : entry point
-	*(--t->ctx.esp) = 0;		// push invalid return address (the run_thread function never returns)
-
-	t->ctx.eip = (void(*)())run_thread;
-	t->state = T_STATE_PAUSED;
-
-	t->current_pd_d = get_kernel_pagedir();
-
-	t->proc = 0;	// used by L1 functions
-
-	return t;
-}
-
-// ========== //
-// SETUP CODE //
-// ========== //
-
-static void irq0_handler(registers_t *regs) {
-	if (current_thread != 0)
-		irq0_save_context_and_enter_scheduler(&current_thread->ctx);
-}
-void threading_setup(entry_t cont, void* arg) {
-	set_pit_frequency(TASK_SWITCH_FREQUENCY);
-	idt_set_irq_handler(IRQ0, irq0_handler);
-
-	thread_t *t = new_thread(cont, arg);
-	ASSERT(t != 0);
-
-	resume_thread(t, false);
-
-	run_scheduler();	// never returns
-	ASSERT(false);
-}
-
-// ======================= //
-// TASK STATE MANIPULATION //
-// ======================= //
-
-void yield() {
-	if (current_thread == 0) {
-		// might happen before threading is initialized
-		// (but should not...)
-		dbg_printf("Warning: probable deadlock.\n");
-	} else {
-		save_context_and_enter_scheduler(&current_thread->ctx);
-	}
-}
-
-void pause() {
-	bool st = disable_interrupts();
-
-	current_thread->state = T_STATE_PAUSED;
-	save_context_and_enter_scheduler(&current_thread->ctx);
-
-	resume_interrupts(st);
-}
-
-void resume_thread(thread_t *thread, bool run_at_once) {
-	bool st = disable_interrupts();
-
-	if (thread->state == T_STATE_PAUSED) {
-		thread->state = T_STATE_RUNNING;
-		enqueue_thread(thread, false);
-	}
-	if (run_at_once) yield();
-
-	resume_interrupts(st);
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/lib/buffer.c b/kernel/lib/buffer.c
deleted file mode 100644
index d2f9644..0000000
--- a/kernel/lib/buffer.c
+++ /dev/null
@@ -1,167 +0,0 @@
-#include <kmalloc.h>
-
-#include <buffer.h>
-#include <string.h>
-
-#include <sys.h>
-
-// three types of buffers
-#define T_BYTES		1
-#define T_SLICE		2
-#define T_CONCAT	3
-
-struct buffer {
-	uint16_t rc, type;		// takes less space like this
-	size_t len;
-	union {
-		struct {
-			const char* data;
-			bool owned;
-		} bytes;
-		struct {
-			struct buffer *buf;
-			size_t begin;
-		} slice;
-		struct {
-			struct buffer *a, *b;
-		} concat;
-	};
-};
-
-void buffer_ref(buffer_t *b) {
-	b->rc++;
-}
-
-void buffer_unref(buffer_t *b) {
-	b->rc--;
-	if (b->rc == 0) {
-		switch (b->type) {
-			case T_BYTES:
-				if (b->bytes.owned) kfree((void*)b->bytes.data);
-				break;
-			case T_SLICE:
-				buffer_unref(b->slice.buf);
-				break;
-			case T_CONCAT:
-				buffer_unref(b->concat.a);
-				buffer_unref(b->concat.b);
-				break;
-			default:
-				ASSERT(false);
-		}
-		kfree(b);
-	}
-}
-
-size_t buffer_size(buffer_t *b) {
-	return b->len;
-}
-
-size_t read_buffer(buffer_t *b, char* dest, size_t begin, size_t n) {
-	if (begin >= b->len) return 0;
-	if (begin + n >= b->len) n = b->len - begin;
-
-	switch (b->type) {
-		case T_BYTES:
-			memcpy(dest, b->bytes.data + begin, n);
-			break;
-		case T_SLICE:
-			read_buffer(b->slice.buf, dest, begin + b->slice.begin, n);
-			break;
-		case T_CONCAT: {
-			size_t la = b->concat.a->len;
-			if (begin < la) {
-				size_t r = read_buffer(b->concat.a, dest, begin, n);
-				if (r < n) {
-					ASSERT(read_buffer(b->concat.b, dest, 0, n - r) == n - r);
-				}
-			} else {
-				ASSERT(read_buffer(b->concat.b, dest, begin - la, n) == n);
-			}
-			break;
-		}
-		default:
-			ASSERT(false);
-	}
-
-	return n;
-}
-
-// ========================= //
-// BUFFER CREATION FUNCTIONS //
-// ========================= //
-
-buffer_t *buffer_from_bytes_nocopy(const char* data, size_t n, bool own_bytes) {
-	buffer_t *b = (buffer_t*)kmalloc(sizeof(buffer_t));
-	if (b == 0) return 0;
-
-	b->rc = 1;
-	b->type = T_BYTES;
-	b->len = n;
-	b->bytes.data = data;
-	b->bytes.owned = own_bytes;
-
-	return b;
-}
-buffer_t *buffer_from_bytes(const char* data, size_t n) {
-	char* data2 = (char*)kmalloc(n);
-	if (data2 == 0) return 0;
-
-	memcpy(data2, data, n);
-
-	buffer_t *b = buffer_from_bytes_nocopy(data2, n, true);
-	if (b == 0) {
-		kfree(data2);
-		return 0;
-	}
-
-	return b;
-}
-
-
-buffer_t* buffer_slice(buffer_t* src, size_t begin, size_t n) {
-	if (begin + n > src->len) return 0;	// invalid request
-
-	buffer_t *b = (buffer_t*)kmalloc(sizeof(buffer_t));
-	if (b == 0) return 0;
-
-	b->rc = 1;
-	b->type = T_SLICE;
-	b->len = n;
-	b->slice.buf = src;
-	b->slice.begin = begin;
-
-	return b;
-}
-
-buffer_t* buffer_concat(buffer_t* a, buffer_t* b) {
-	buffer_t *r = (buffer_t*)kmalloc(sizeof(buffer_t));
-	if (r == 0) return r;
-
-	r->rc = 1;
-	r->type = T_CONCAT;
-	r->len = a->len + b->len;
-	r->concat.a = a;
-	r->concat.b = b;
-
-	return r;
-}
-
-buffer_t* buffer_slice_k(buffer_t *b, size_t begin, size_t n) {
-	buffer_t *r = buffer_slice(b, begin, n);
-	if (r != 0) {
-		buffer_ref(b);
-	}
-	return r;
-}
-
-buffer_t* buffer_concat_k(buffer_t *a, buffer_t *b) {
-	buffer_t *r = buffer_concat(a, b);
-	if (r != 0) {
-		buffer_ref(a);
-		buffer_ref(b);
-	}
-	return r;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/lib/hashtbl.c b/kernel/lib/hashtbl.c
deleted file mode 100644
index 91fb3cb..0000000
--- a/kernel/lib/hashtbl.c
+++ /dev/null
@@ -1,166 +0,0 @@
-#include <hashtbl.h>
-#include <kmalloc.h>
-#include <string.h>
-
-#define DEFAULT_INIT_SIZE 16
-#define SLOT_OF_HASH(k, nslots) (((size_t)(k)*21179)%(size_t)(nslots))
-
-typedef struct hashtbl_item {
-	void* key;
-	void* val;
-	struct hashtbl_item *next;
-} hashtbl_item_t;
-
-// When nitems > size * 3/4, size is multiplied by two
-// When nitems < size * 1/4, size is divided by two
-struct hashtbl {
-	key_eq_fun_t ef;
-	hash_fun_t hf;
-	size_t size, nitems;
-	hashtbl_item_t **items;
-};
-
-hashtbl_t *create_hashtbl(key_eq_fun_t ef, hash_fun_t hf, size_t initial_size) {
-	hashtbl_t *ht = (hashtbl_t*)kmalloc(sizeof(hashtbl_t));
-	if (ht == 0) return 0;
-
-	ht->ef = ef;
-	ht->hf = hf;
-
-	ht->size = (initial_size == 0 ? DEFAULT_INIT_SIZE : initial_size);
-	ht->nitems = 0;
-
-	ht->items = (hashtbl_item_t**)kmalloc(ht->size * sizeof(hashtbl_item_t*));
-	if (ht->items == 0) {
-		kfree(ht);
-		return 0;
-	}
-
-	for (size_t i = 0; i < ht->size; i++) ht->items[i] = 0;
-
-	return ht;
-}
-
-void delete_hashtbl(hashtbl_t *ht) {
-	// Free items
-	for (size_t i = 0; i < ht->size; i++) {
-		while (ht->items[i] != 0) {
-			hashtbl_item_t *n = ht->items[i]->next;
-			kfree(ht->items[i]);
-			ht->items[i] = n;
-		}
-	}
-
-	// Free table
-	kfree(ht->items);
-	kfree(ht);
-}
-
-static void hashtbl_check_size(hashtbl_t *ht) {
-	size_t nsize = 0;
-	if (4 * ht->nitems < ht->size) nsize = ht->size / 2;
-	if (4 * ht->nitems > 3 * ht->size) nsize = ht->size * 2;
-
-	if (nsize != 0) {
-		hashtbl_item_t **nitems = (hashtbl_item_t**)kmalloc(nsize * sizeof(hashtbl_item_t*));
-		if (nitems == 0) return;	// if we can't realloc, too bad, we just lose space
-
-		for (size_t i = 0; i < nsize; i++) nitems[i] = 0;
-
-		// rehash
-		for (size_t i = 0; i < ht->size; i++) {
-			while (ht->items[i] != 0) {
-				hashtbl_item_t *x = ht->items[i];
-				ht->items[i] = x->next;
-
-				size_t slot = SLOT_OF_HASH(ht->hf(x->key), nsize);
-				x->next = nitems[slot];
-				nitems[slot] = x;
-			}
-		}
-		kfree(ht->items);
-		ht->size = nsize;
-		ht->items = nitems;
-	}
-}
-
-int hashtbl_add(hashtbl_t *ht, void* key, void* v) {
-	size_t slot = SLOT_OF_HASH(ht->hf(key), ht->size);
-
-	hashtbl_item_t *i = (hashtbl_item_t*)kmalloc(sizeof(hashtbl_item_t));
-	if (i == 0) return 1;	// OOM
-
-	// make sure item is not already present
-	hashtbl_remove(ht, key);
-
-	i->key = key;
-	i->val = v;
-	i->next = ht->items[slot];
-	ht->items[slot] = i;
-	ht->nitems++;
-
-	hashtbl_check_size(ht);
-
-	return 0;
-}
-
-void* hashtbl_find(hashtbl_t* ht, void* key) {
-	size_t slot = SLOT_OF_HASH(ht->hf(key), ht->size);
-
-	for (hashtbl_item_t *i = ht->items[slot]; i != 0; i = i->next) {
-		if (ht->ef(i->key, key)) return i->val;
-	}
-
-	return 0;
-}
-
-void hashtbl_remove(hashtbl_t* ht, void* key) {
-	size_t slot = SLOT_OF_HASH(ht->hf(key), ht->size);
-
-	if (ht->items[slot] == 0) return;
-
-	if (ht->ef(ht->items[slot]->key, key)) {
-		hashtbl_item_t *x = ht->items[slot];
-		ht->items[slot] = x->next;
-		kfree(x);
-		ht->nitems--;
-	} else {
-		for (hashtbl_item_t *i = ht->items[slot]; i->next != 0; i = i->next) {
-			if (ht->ef(i->next->key, key)) {
-				hashtbl_item_t *x = i->next;
-				i->next = x->next;
-				kfree(x);
-				ht->nitems--;
-				break;
-			}
-		}
-	}
-	
-	hashtbl_check_size(ht);
-}
-
-size_t hashtbl_count(hashtbl_t* ht) {
-	return ht->nitems;
-}
-
-hash_t id_hash_fun(const void* v) {
-	return (hash_t)v;
-}
-
-hash_t str_hash_fun(const void* v) {
-	hash_t h = 712;
-	for (char* s = (char*)v; *s != 0; s++) {
-		h = h * 101 + *s;
-	}
-	return h;
-}
-
-bool id_key_eq_fun(const void* a, const void* b) {
-	return a == b;
-}
-
-bool str_key_eq_fun(const void* a, const void* b) {
-	return strcmp((const char*)a, (const char*)b) == 0;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/lib/mutex.c b/kernel/lib/mutex.c
deleted file mode 100644
index cda8049..0000000
--- a/kernel/lib/mutex.c
+++ /dev/null
@@ -1,27 +0,0 @@
-#include <mutex.h>
-
-/*	Internal use only. This function is atomic, meaning it cannot be interrupted by a system task switch. */
-static uint32_t atomic_exchange(uint32_t* ptr, uint32_t newval) {
-	uint32_t r;
-	asm volatile("xchg (%%ecx), %%eax" : "=a"(r) : "c"(ptr), "a"(newval));
-	return r;
-}
-
-void mutex_lock(uint32_t* mutex) {
-	while (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) {
-		yield();
-	}
-}
-
-int mutex_try_lock(uint32_t* mutex) {
-	if (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) {
-		return 0;
-	}
-	return 1;
-}
-
-void mutex_unlock(uint32_t* mutex) {
-	*mutex = MUTEX_UNLOCKED;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/lib/printf.c b/kernel/lib/printf.c
deleted file mode 100644
index 68e08d8..0000000
--- a/kernel/lib/printf.c
+++ /dev/null
@@ -1,120 +0,0 @@
-#include <printf.h>
-#include <stdarg.h>
-
-int snprintf(char * buff, size_t len, const char *format, ...) {
-	va_list ap;
-
-	va_start(ap, format);
-	len = vsnprintf(buff, len, format, ap);
-	va_end(ap);
-
-	return len;
-}
-
-int vsnprintf(char *buff, size_t len, const char* format, va_list ap){
-	size_t i, result;
-
-	if (!buff || !format)
-		return -1;
-
-#define PUTCHAR(thechar) \
-	do { \
-		if (result < len-1) \
-		*buff++ = (thechar);  \
-		result++; \
-	} while (0)
-
-	result = 0;
-	for(i = 0; format[i] != '\0' ; i++) {
-		if (format[i] == '%') {
-			i++;
-			switch(format[i]) {
-				case '%':
-					PUTCHAR('%');
-					break;
-
-				case 'i':;
-				case 'd': {
-					 int integer = va_arg(ap,int);
-					 int cpt2 = 0;
-					 char buff_int[16];
-
-					 if (integer<0)
-						 PUTCHAR('-');
-
-					 do {
-						 int m10 = integer%10;
-						 m10 = (m10 < 0)? -m10:m10;
-						 buff_int[cpt2++] = (char)('0'+ m10);
-						 integer = integer/10;
-					 } while(integer != 0);
-
-					 for(cpt2 = cpt2 - 1; cpt2 >= 0; cpt2--)
-						 PUTCHAR(buff_int[cpt2]);
-
-					 break;
-				}
-				case 'c': {
-					 int value = va_arg(ap,int);
-					 PUTCHAR((char)value);
-					 break;
-				}
-				case 's': {
-					 char *string = va_arg(ap,char *);
-					 if (!string)
-						 string = "(null)";
-					 for(; *string != '\0' ; string++)
-						 PUTCHAR(*string);
-					 break;
-				}
-				case 'x': {
-					 unsigned int hexa = va_arg(ap,int);
-					 unsigned int nb;
-					 int j, had_nonzero = 0;
-					 for(j = 0; j < 8; j++) {
-						 nb = (unsigned int)(hexa << (j*4));
-						 nb = (nb >> 28) & 0xf;
-						 // Skip the leading zeros
-						 if (nb == 0) {
-							 if (had_nonzero)
-								 PUTCHAR('0');
-						 } else {
-							 had_nonzero = 1;
-							 if (nb < 10)
-								 PUTCHAR('0'+nb);
-							 else
-								 PUTCHAR('a'+(nb-10));
-						 }
-					 }
-					 if (!had_nonzero)
-						 PUTCHAR('0');
-					 break;
-				}
-				case 'p': {
-					 unsigned int hexa = va_arg(ap,int);
-					 unsigned int nb;
-					 int j;
-					 for (j = 0; j < 8; j++) {
-						 nb = (unsigned int)(hexa << (j*4));
-						 nb = (nb >> 28) & 0xf;
-						 if (nb < 10)
-							 PUTCHAR('0'+nb);
-						 else
-							 PUTCHAR('a'+(nb-10));
-					 }
-					 break;
-				}
-				default:
-					 PUTCHAR('%');
-					 PUTCHAR(format[i]);
-			}
-		} else {
-			PUTCHAR(format[i]);
-		}
-	}
-
-	*buff = '\0';
-	return result;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/lib/slab_alloc.c b/kernel/lib/slab_alloc.c
deleted file mode 100644
index 714c49f..0000000
--- a/kernel/lib/slab_alloc.c
+++ /dev/null
@@ -1,283 +0,0 @@
-#include <slab_alloc.h>
-
-typedef struct object {
-	struct object *next;
-} object_t;
-
-typedef struct cache {
-	void* region_addr;
-	
-	uint32_t n_free_objs;
-	object_t* first_free_obj;
-
-	struct cache *next_cache;	// next cache in this slab
-} cache_t;
-
-typedef struct region {
-	void* region_addr;
-	size_t region_size;
-	struct region *next_region;
-	bool contains_descriptors;
-} region_t;
-
-typedef union descriptor {
-	cache_t c;
-	region_t r;
-	union descriptor *next_free;
-} descriptor_t;
-
-typedef struct slab {
-	cache_t *first_cache;		// linked list of caches
-} slab_t;
-
-struct mem_allocator {
-	const slab_type_t *types;
-	slab_t *slabs;
-
-	descriptor_t *first_free_descriptor;
-	region_t *all_regions;
-
-	page_alloc_fun_t alloc_fun;
-	page_free_fun_t free_fun;
-};
-
-// ============================================== //
-// Helper functions for the manipulation of lists //
-// ============================================== //
-
-static void add_free_descriptor(mem_allocator_t *a, descriptor_t *c) {
-	c->next_free = a->first_free_descriptor;
-	a->first_free_descriptor = c;
-}
-
-static descriptor_t *take_descriptor(mem_allocator_t *a) {
-	if (a->first_free_descriptor == 0) {
-		void* p = a->alloc_fun(PAGE_SIZE);
-		if (p == 0) return 0;
-
-		const void* end = p + PAGE_SIZE;
-		for (descriptor_t *i = (descriptor_t*)p; i + 1 <= (descriptor_t*)end; i++) {
-			add_free_descriptor(a, i);
-		}
-
-		// register the descriptor region
-		descriptor_t *dd = a->first_free_descriptor;
-		ASSERT(dd != 0);
-		a->first_free_descriptor = dd->next_free;
-
-		region_t *drd = &dd->r;
-		drd->region_addr = p;
-		drd->region_size = PAGE_SIZE;
-		drd->contains_descriptors = true;
-		drd->next_region = a->all_regions;
-		a->all_regions = drd;
-	}
-
-	descriptor_t *x = a->first_free_descriptor;
-	ASSERT(x != 0);
-	a->first_free_descriptor = x->next_free;
-	return x;
-}
-
-// ============================== //
-// The actual allocator functions //
-// ============================== //
-
-mem_allocator_t* create_slab_allocator(const slab_type_t *types, page_alloc_fun_t af, page_free_fun_t ff) {
-	union {
-		void* addr;
-		mem_allocator_t *a;
-		slab_t *s;
-		descriptor_t *d;
-	} ptr;
-
-	ptr.addr = af(PAGE_SIZE);
-	if (ptr.addr == 0) return 0;	// could not allocate
-	const void* end_addr = ptr.addr + PAGE_SIZE;
-
-	mem_allocator_t *a = ptr.a;
-	ptr.a++;
-
-	a->all_regions = 0;
-	a->alloc_fun = af;
-	a->free_fun = ff;
-
-	a->types = types;
-	a->slabs = ptr.s;
-	for (const slab_type_t *t = types; t->obj_size != 0; t++) {
-		ASSERT(t->obj_size >= sizeof(object_t));
-		ptr.s->first_cache = 0;
-		ptr.s++;
-	}
-
-	a->first_free_descriptor = 0;
-	while (ptr.d + 1 <= (descriptor_t*)end_addr) {
-		add_free_descriptor(a, ptr.d);
-		ptr.d++;
-	}
-
-	return a;
-}
-
-static void stack_and_destroy_regions(page_free_fun_t ff, region_t *r) {
-	if (r == 0) return;
-	void* addr = r->region_addr;
-	ASSERT(r != r->next_region);
-	stack_and_destroy_regions(ff, r->next_region);
-	ff(addr);
-}
-void destroy_slab_allocator(mem_allocator_t *a) {
-	for (int i = 0; a->types[i].obj_size != 0; i++) {
-		for (cache_t *c = a->slabs[i].first_cache; c != 0; c = c->next_cache) {
-			a->free_fun(c->region_addr);
-		}
-	}
-	region_t *dr = 0;
-	region_t *i = a->all_regions;
-	while (i != 0) {
-		region_t *r = i;
-		i = r->next_region;
-		if (r->contains_descriptors) {
-			r->next_region = dr;
-			dr = r;
-		} else {
-			a->free_fun(r->region_addr);
-		}
-	}
-	stack_and_destroy_regions(a->free_fun, dr);
-	a->free_fun(a);
-}
-
-void* slab_alloc(mem_allocator_t* a, size_t sz) {
-	for (int i = 0; a->types[i].obj_size != 0; i++) {
-		const size_t obj_size = a->types[i].obj_size;
-		if (sz <= obj_size) {
-			// find a cache with free space
-			cache_t *fc = a->slabs[i].first_cache;
-			while (fc != 0 && fc->n_free_objs == 0) {
-				ASSERT(fc->first_free_obj == 0); // make sure n_free == 0 iff no object in the free stack
-				fc = fc->next_cache;
-			}
-			// if none found, try to allocate a new one
-			if (fc == 0) {
-				descriptor_t *fcd = take_descriptor(a);
-				if (fcd == 0) return 0;
-
-				fc = &fcd->c;
-				ASSERT((descriptor_t*)fc == fcd);
-
-				const size_t cache_size = a->types[i].pages_per_cache * PAGE_SIZE;
-				fc->region_addr = a->alloc_fun(cache_size);
-				if (fc->region_addr == 0) {
-					add_free_descriptor(a, fcd);
-					return 0;
-				}
-
-				fc->n_free_objs = 0;
-				fc->first_free_obj = 0;
-				for (void* p = fc->region_addr; p + obj_size <= fc->region_addr + cache_size; p += obj_size) {
-					object_t *x = (object_t*)p;
-					x->next = fc->first_free_obj;
-					fc->first_free_obj = x;
-					fc->n_free_objs++;
-				}
-				ASSERT(fc->n_free_objs == cache_size / obj_size);
-
-				fc->next_cache = a->slabs[i].first_cache;
-				a->slabs[i].first_cache = fc;
-			}
-			// allocate on fc
-			ASSERT(fc != 0 && fc->n_free_objs > 0);
-
-			object_t *x = fc->first_free_obj;
-			fc->first_free_obj = x->next;
-			fc->n_free_objs--;
-
-			ASSERT((fc->n_free_objs == 0) == (fc->first_free_obj == 0));
-
-			// TODO : if fc is full, put it at the end
-			return x;
-		}
-	}
-
-	// otherwise directly allocate using a->alloc_fun
-	descriptor_t *rd = take_descriptor(a);
-	if (rd == 0) return 0;
-	region_t *r = &rd->r;
-	ASSERT((descriptor_t*)r == rd);
-
-	r->region_addr = a->alloc_fun(sz);
-	if (r->region_addr == 0) {
-		add_free_descriptor(a, rd);
-		return 0;
-	} else {
-		r->region_size = sz;
-		r->contains_descriptors = false;
-
-		r->next_region = a->all_regions;
-		a->all_regions = r;
-
-		return (void*)r->region_addr;
-	}
-}
-
-void slab_free(mem_allocator_t* a, void* addr) {
-
-	for (int i = 0; a->types[i].obj_size != 0; i++) {
-		size_t region_size = PAGE_SIZE * a->types[i].pages_per_cache;
-		for (cache_t *r = a->slabs[i].first_cache; r != 0; r = r->next_cache) {
-			if (addr >= r->region_addr && addr < r->region_addr + region_size) {
-				ASSERT((addr - r->region_addr) % a->types[i].obj_size == 0);
-
-				object_t *o = (object_t*)addr;
-				o->next = r->first_free_obj;
-				r->first_free_obj = o;
-				r->n_free_objs++;
-
-				if (r->n_free_objs == region_size / a->types[i].obj_size) {
-					// region is completely unused, free it.
-					if (a->slabs[i].first_cache == r) {
-						a->slabs[i].first_cache = r->next_cache;
-					} else {
-						for (cache_t *it = a->slabs[i].first_cache; it->next_cache != 0; it = it->next_cache) {
-							if (it->next_cache == r) {
-								it->next_cache = r->next_cache;
-								break;
-							}
-						}
-					}
-					a->free_fun(r->region_addr);
-					add_free_descriptor(a, (descriptor_t*)r);
-				}
-				return;
-			}
-		}
-	}
-
-	// otherwise the block was directly allocated : look for it in regions.
-	ASSERT(a->all_regions != 0);
-
-	if (a->all_regions->region_addr == addr) {
-		a->free_fun(addr);	// found it, free it
-
-		region_t *r = a->all_regions;
-		a->all_regions = r->next_region;
-		add_free_descriptor(a, (descriptor_t*)r);
-	} else {
-		for (region_t *i = a->all_regions; i->next_region != 0; i = i->next_region) {
-			if (i->next_region->region_addr == addr) {
-				a->free_fun(addr);	// found it, free it
-
-				region_t *r = i->next_region;
-				ASSERT(!r->contains_descriptors);
-				i->next_region = r->next_region;
-				add_free_descriptor(a, (descriptor_t*)r);
-				return;
-			}
-		}
-		ASSERT(false);
-	}
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
-
diff --git a/kernel/lib/string.c b/kernel/lib/string.c
deleted file mode 100644
index 9dce27b..0000000
--- a/kernel/lib/string.c
+++ /dev/null
@@ -1,90 +0,0 @@
-#include <string.h>
-
-
-size_t strlen(const char* str) {
-	size_t ret = 0;
-	while (str[ret] != 0)
-		ret++;
-	return ret;
-}
-
-char *strchr(const char *str, char c) {
-	while (*str) {
-		if (*str == c) return (char*)str;
-		str++;
-	}
-	return NULL;
-}
-
-char *strcpy(char *dest, const char *src) {
-	memcpy(dest, src, strlen(src) + 1);
-	return (char*)src;
-}
-
-char *strcat(char *dest, const char *src) {
-	char *dest2 = dest;
-	dest2 += strlen(dest) - 1;
-	while (*src) {
-		*dest2 = *src;
-		src++;
-		dest2++;
-	}
-	*dest2 = 0;
-	return dest;
-}
-
-int strcmp(const char *s1, const char *s2) {
-	while ((*s1) && (*s1 == *s2)) {
-		s1++;
-		s2++;
-	}
-	return (*(unsigned char*)s1 - *(unsigned char*)s2);
-}
-
-void *memcpy(void *vd, const void *vs, size_t count) {
-	uint8_t *dest = (uint8_t*)vd, *src = (uint8_t*)vs;
-	size_t f = count % 4, n = count / 4, i;
-	const uint32_t* s = (uint32_t*)src;
-	uint32_t* d = (uint32_t*)dest;
-	for (i = 0; i < n; i++) {
-		d[i] = s[i];
-	}
-	if (f != 0) {
-		for (i = count - f; i < count; i++) {
-			dest[i] = src[i];
-		}
-	}
-	return vd;
-}
-
-void *memmove(void *vd, const void *vs, size_t count) {
-	uint8_t *dest = (uint8_t*)vd, *src = (uint8_t*)vs;
-
-	if (vd < vs) {
-		for (size_t i = 0; i < count; i++)
-			dest[i] = src[i];
-	} else {
-		for (size_t i = 0; i < count; i++)
-			dest[count - i] = src[count - i];
-	}
-	return vd;
-}
-
-int memcmp(const void *va, const void *vb, size_t count) {
-	uint8_t *a = (uint8_t*)va;
-	uint8_t *b = (uint8_t*)vb;
-	for (size_t i = 0; i < count; i++) {
-		if (a[i] != b[i]) return (int)a[i] - (int)b[i];
-	}
-	return 0;
-}
-
-void *memset(void *dest, int val, size_t count) {
-	uint8_t *dest_c = (uint8_t*)dest;
-	for (size_t i = 0; i < count; i++) {
-		dest_c[i] = val;
-	}
-	return dest;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/lib_tests/Makefile b/kernel/lib_tests/Makefile
deleted file mode 100644
index 4a21edf..0000000
--- a/kernel/lib_tests/Makefile
+++ /dev/null
@@ -1,2 +0,0 @@
-slab_test.bin: slab_test.c ../include/slab_alloc.h ../lib/slab_alloc.c
-	gcc -m32 -o $@ -std=c99 -I ../include slab_test.c ../lib/slab_alloc.c
diff --git a/kernel/lib_tests/slab_test.c b/kernel/lib_tests/slab_test.c
deleted file mode 100644
index 747c785..0000000
--- a/kernel/lib_tests/slab_test.c
+++ /dev/null
@@ -1,44 +0,0 @@
-#include <slab_alloc.h>
-#include <stdlib.h>
-#include <stdio.h>
-
-slab_type_t slab_sizes[] = {
-	{ "8B obj", 8, 1 },
-	{ "16B obj", 16, 2 },
-	{ "32B obj", 32, 2 },
-	{ "64B obj", 64, 2 },
-	{ "128B obj", 128, 2 },
-	{ "256B obj", 256, 4 },
-	{ "512B obj", 512, 4 },
-	{ "1KB obj", 1024, 8 },
-	{ "2KB obj", 2048, 8 },
-	{ "4KB obj", 4096, 16 },
-	{ 0, 0, 0 }
-};
-
-
-int main(int argc, char *argv[]) {
-	mem_allocator_t *a =
-		create_slab_allocator(slab_sizes, malloc, free);
-
-	const int m = 10000;
-	uint32_t* ptr[m];
-	for (int i = 0; i < m; i++) {
-		size_t s = 1 << ((i * 7) % 12 + 2);
-		ptr[i] = (uint32_t*)slab_alloc(a, s);
-		ASSERT(ptr[i] != 0);
-		*ptr[i] = ((i * 2117) % (1<<30));
-		printf("Alloc %i : 0x%p\n", s, ptr[i]);
-	}
-	for (int i = 0; i < m; i++) {
-		for (int j = i; j < m; j++) {
-			ASSERT(*ptr[j] == (j * 2117) % (1<<30));
-		}
-		slab_free(a, ptr[i]);
-	}
-	destroy_slab_allocator(a);
-
-	return 0;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/linker.ld b/kernel/linker.ld
deleted file mode 100644
index 1203950..0000000
--- a/kernel/linker.ld
+++ /dev/null
@@ -1,43 +0,0 @@
-ENTRY (loader)
-
-SECTIONS{
-	k_highhalf_addr = 0xC0000000;
-
-	. = 0x00100000;
-
-	.setup : {
-		*(.setup)
-	}
-
-	. += k_highhalf_addr;
-
-	.text : AT(ADDR(.text) - k_highhalf_addr) {
-		*(.text)
-	}
-
-	.rodata ALIGN (0x1000) : AT(ADDR(.rodata) - k_highhalf_addr) {
-		*(.rodata)
-	}
-
-	.data ALIGN (0x1000) : AT(ADDR(.data) - k_highhalf_addr) {
-		start_ctors = .;
-		*(.ctor*)
-		end_ctors = .;
-		start_dtors = .;
-		*(.dtor*)
-		end_dtors = .;
-		*(.data)
-		*(.locks)
-	}
-
-	.bss : AT(ADDR(.bss) - k_highhalf_addr) {
-		sbss = .;
-		*(COMMON)
-		*(.bss)
-		ebss = .;
-	}
-
-	k_end_addr = .;
-}
-
-/* vim: set ts=4 sw=4 tw=0 noet :*/