56 files changed, 254 insertions, 100 deletions

diff --git a/.gitignore b/.gitignore
index 084889f..4fcbaae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,11 @@
 *~
 *.swp
 
+tags
+
 *.o
 *.bin
+*.lib
 *.map
 
 *.iso
@@ -18,3 +21,4 @@ doc/html
 
 # bochs debugger
 bx_enh_dbg.ini
+
diff --git a/.vimrc b/.vimrc
new file mode 100644
index 0000000..06a0ef4
--- /dev/null
+++ b/.vimrc
@@ -0,0 +1,14 @@
+autocmd VimEnter * NERDTree
+autocmd VimEnter * wincmd p
+
+map <C-F12> :!ctags -R --sort=yes --c-kinds=+pl --fields=+iaS --extra=+q kernel<CR>
+
+
+let g:syntastic_always_populate_loc_list = 1
+let g:syntastic_auto_loc_list = 1
+let g:syntastic_check_on_open = 1
+let g:syntastic_check_on_wq = 0
+
+let g:syntastic_c_gcc_exec = 'i586-elf-gcc'
+let g:syntastic_c_include_dirs = [ 'src/kernel/include', 'src/kernel', 'src/common/include' ]
+let g:syntastic_c_compiler_options = '-ffreestanding -Wall -Wextra -std=gnu99 -Wno-unused-parameter'
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/make_cdrom.sh b/make_cdrom.sh
index ef9e5f7..82a3bd2 100755
--- a/make_cdrom.sh
+++ b/make_cdrom.sh
@@ -8,7 +8,7 @@ if [ ! -e cdrom/boot/grub/stage2_eltorito ]; then
 fi
 
 cp menu_cdrom.lst cdrom/boot/grub/menu.lst
-cp kernel/kernel.bin cdrom; strip cdrom/kernel.bin
+cp src/kernel/kernel.bin cdrom; strip cdrom/kernel.bin
 
 genisoimage -R -b boot/grub/stage2_eltorito -no-emul-boot \
 	-boot-load-size 4 -boot-info-table -input-charset ascii \
diff --git a/run_bochs_debug.sh b/run_bochs_debug.sh
index df6c0d4..335b810 100755
--- a/run_bochs_debug.sh
+++ b/run_bochs_debug.sh
@@ -2,6 +2,7 @@
 
 cd `dirname $0`
 
-make -C kernel || exit 1
+make -C src/common || exit 1
+make -C src/kernel || exit 1
 ./make_cdrom.sh
 bochs -f bochs_debug.cfg -q
diff --git a/run_qemu.sh b/run_qemu.sh
index 6c76909..59f1f19 100755
--- a/run_qemu.sh
+++ b/run_qemu.sh
@@ -2,5 +2,6 @@
 
 cd `dirname $0`
 
-make -C kernel || exit 1
-qemu-system-i386 -kernel kernel/kernel.bin -serial stdio -m 16
+make -C src/common || exit 1
+make -C src/kernel || exit 1
+qemu-system-i386 -kernel src/kernel/kernel.bin -serial stdio -m 16
diff --git a/run_qemu_debug.sh b/run_qemu_debug.sh
index 71ee6d3..9e84613 100755
--- a/run_qemu_debug.sh
+++ b/run_qemu_debug.sh
@@ -2,6 +2,7 @@
 
 cd `dirname $0`
 
-make -C kernel || exit 1
-qemu-system-i386 -kernel kernel/kernel.bin -serial stdio -s -S &
-(sleep 0.1; gdb kernel/kernel.bin -x gdb_cmd)
+make -C src/common || exit 1
+make -C src/kernel || exit 1
+qemu-system-i386 -kernel src/kernel/kernel.bin -serial stdio -s -S &
+(sleep 0.1; gdb src/kernel/kernel.bin -x gdb_cmd)
diff --git a/src/common/Makefile b/src/common/Makefile
new file mode 100644
index 0000000..d27c6d5
--- /dev/null
+++ b/src/common/Makefile
@@ -0,0 +1,11 @@
+OBJ = string.o printf.o slab_alloc.o mutex.o hashtbl.o buffer.o
+
+LIB = 
+
+CFLAGS = -I ./include
+
+LDFLAGS = 
+
+OUT = common.lib
+
+include ../rules.make
diff --git a/src/common/README b/src/common/README
new file mode 100644
index 0000000..deae76f
--- /dev/null
+++ b/src/common/README
@@ -0,0 +1,18 @@
+This directory contains the library functions common to userland
+and kernel code.
+
+It relies on a few functions being exported :
+
+- panic(char* msg, char* file, int line)
+- panic_assert(char* assert, char* file, int line)
+- dbg_print(const char* str)
+- void* malloc(size_t size)
+- free(void* ptr)
+
+These function are supposed to be defined in the code that calls
+the common functions. The headers for these functions are to be
+found in `assert.h` and `malloc.h`.
+
+Panic and panic_assert end the execution of the current program
+(or of the kernel when in kernel-mode).
+
diff --git a/kernel/lib/buffer.c b/src/common/buffer.c
index d2f9644..21f1ec4 100644
--- a/kernel/lib/buffer.c
+++ b/src/common/buffer.c
@@ -1,9 +1,9 @@
-#include <kmalloc.h>
+#include <malloc.h>
 
 #include <buffer.h>
 #include <string.h>
 
-#include <sys.h>
+#include <debug.h>
 
 // three types of buffers
 #define T_BYTES		1
@@ -37,7 +37,7 @@ void buffer_unref(buffer_t *b) {
 	if (b->rc == 0) {
 		switch (b->type) {
 			case T_BYTES:
-				if (b->bytes.owned) kfree((void*)b->bytes.data);
+				if (b->bytes.owned) free((void*)b->bytes.data);
 				break;
 			case T_SLICE:
 				buffer_unref(b->slice.buf);
@@ -49,7 +49,7 @@ void buffer_unref(buffer_t *b) {
 			default:
 				ASSERT(false);
 		}
-		kfree(b);
+		free(b);
 	}
 }
 
@@ -92,7 +92,7 @@ size_t read_buffer(buffer_t *b, char* dest, size_t begin, size_t n) {
 // ========================= //
 
 buffer_t *buffer_from_bytes_nocopy(const char* data, size_t n, bool own_bytes) {
-	buffer_t *b = (buffer_t*)kmalloc(sizeof(buffer_t));
+	buffer_t *b = (buffer_t*)malloc(sizeof(buffer_t));
 	if (b == 0) return 0;
 
 	b->rc = 1;
@@ -104,14 +104,14 @@ buffer_t *buffer_from_bytes_nocopy(const char* data, size_t n, bool own_bytes) {
 	return b;
 }
 buffer_t *buffer_from_bytes(const char* data, size_t n) {
-	char* data2 = (char*)kmalloc(n);
+	char* data2 = (char*)malloc(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);
+		free(data2);
 		return 0;
 	}
 
@@ -122,7 +122,7 @@ buffer_t *buffer_from_bytes(const char* data, size_t n) {
 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));
+	buffer_t *b = (buffer_t*)malloc(sizeof(buffer_t));
 	if (b == 0) return 0;
 
 	b->rc = 1;
@@ -135,7 +135,7 @@ buffer_t* buffer_slice(buffer_t* src, size_t begin, size_t n) {
 }
 
 buffer_t* buffer_concat(buffer_t* a, buffer_t* b) {
-	buffer_t *r = (buffer_t*)kmalloc(sizeof(buffer_t));
+	buffer_t *r = (buffer_t*)malloc(sizeof(buffer_t));
 	if (r == 0) return r;
 
 	r->rc = 1;
diff --git a/src/common/common.lib b/src/common/common.lib
new file mode 100644
index 0000000..16259e6
--- /dev/null
+++ b/src/common/common.lib
diff --git a/kernel/lib/hashtbl.c b/src/common/hashtbl.c
index 91fb3cb..47072b4 100644
--- a/kernel/lib/hashtbl.c
+++ b/src/common/hashtbl.c
@@ -1,5 +1,5 @@
 #include <hashtbl.h>
-#include <kmalloc.h>
+#include <malloc.h>
 #include <string.h>
 
 #define DEFAULT_INIT_SIZE 16
@@ -21,7 +21,7 @@ struct hashtbl {
 };
 
 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));
+	hashtbl_t *ht = (hashtbl_t*)malloc(sizeof(hashtbl_t));
 	if (ht == 0) return 0;
 
 	ht->ef = ef;
@@ -30,9 +30,9 @@ hashtbl_t *create_hashtbl(key_eq_fun_t ef, hash_fun_t hf, size_t initial_size) {
 	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*));
+	ht->items = (hashtbl_item_t**)malloc(ht->size * sizeof(hashtbl_item_t*));
 	if (ht->items == 0) {
-		kfree(ht);
+		free(ht);
 		return 0;
 	}
 
@@ -46,14 +46,14 @@ void delete_hashtbl(hashtbl_t *ht) {
 	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]);
+			free(ht->items[i]);
 			ht->items[i] = n;
 		}
 	}
 
 	// Free table
-	kfree(ht->items);
-	kfree(ht);
+	free(ht->items);
+	free(ht);
 }
 
 static void hashtbl_check_size(hashtbl_t *ht) {
@@ -62,7 +62,7 @@ static void hashtbl_check_size(hashtbl_t *ht) {
 	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*));
+		hashtbl_item_t **nitems = (hashtbl_item_t**)malloc(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;
@@ -78,7 +78,7 @@ static void hashtbl_check_size(hashtbl_t *ht) {
 				nitems[slot] = x;
 			}
 		}
-		kfree(ht->items);
+		free(ht->items);
 		ht->size = nsize;
 		ht->items = nitems;
 	}
@@ -87,7 +87,7 @@ static void hashtbl_check_size(hashtbl_t *ht) {
 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));
+	hashtbl_item_t *i = (hashtbl_item_t*)malloc(sizeof(hashtbl_item_t));
 	if (i == 0) return 1;	// OOM
 
 	// make sure item is not already present
@@ -122,14 +122,14 @@ void hashtbl_remove(hashtbl_t* ht, void* key) {
 	if (ht->ef(ht->items[slot]->key, key)) {
 		hashtbl_item_t *x = ht->items[slot];
 		ht->items[slot] = x->next;
-		kfree(x);
+		free(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);
+				free(x);
 				ht->nitems--;
 				break;
 			}
diff --git a/kernel/include/buffer.h b/src/common/include/buffer.h
index c47e2b4..0d6cfbf 100644
--- a/kernel/include/buffer.h
+++ b/src/common/include/buffer.h
@@ -2,6 +2,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include <stdbool.h>
 
 // The buffer_t type is a simple reference-counted buffer type
 // enabling the creation, sharing, slicing and concatenation of buffers
diff --git a/src/common/include/debug.h b/src/common/include/debug.h
new file mode 100644
index 0000000..a4b8b6f
--- /dev/null
+++ b/src/common/include/debug.h
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+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__); }
+
+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/hashtbl.h b/src/common/include/hashtbl.h
index 16dfefb..16dfefb 100644
--- a/kernel/include/hashtbl.h
+++ b/src/common/include/hashtbl.h
diff --git a/src/common/include/malloc.h b/src/common/include/malloc.h
new file mode 100644
index 0000000..0ba5572
--- /dev/null
+++ b/src/common/include/malloc.h
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+
+// Header is in common/, but implementation is not.
+
+void* malloc(size_t sz);
+void free(void* ptr);
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/mutex.h b/src/common/include/mutex.h
index 6814adf..6814adf 100644
--- a/kernel/include/mutex.h
+++ b/src/common/include/mutex.h
diff --git a/kernel/include/printf.h b/src/common/include/printf.h
index b4e1c1b..b4e1c1b 100644
--- a/kernel/include/printf.h
+++ b/src/common/include/printf.h
diff --git a/kernel/include/slab_alloc.h b/src/common/include/slab_alloc.h
index eb9588d..c8d5d6c 100644
--- a/kernel/include/slab_alloc.h
+++ b/src/common/include/slab_alloc.h
@@ -8,18 +8,19 @@
 #include <stddef.h>
 #include <stdbool.h>
 
+
 #if defined(__linux__)
 //redefine necessary stuff
-#include <assert.h>
+#include <assert.h> 		// standard linux assert.h
 #define ASSERT assert
-#define PAGE_SIZE 0x1000
-#include <stdio.h>
+#include <stdio.h> 
 #define dbg_printf printf
 #else
-#include <sys.h>	// this is macroscope
-#include <dbglog.h>
+#include <debug.h>
 #endif
 
+#define PAGE_SIZE 0x1000
+
 // 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
diff --git a/kernel/include/string.h b/src/common/include/string.h
index 682b25a..682b25a 100644
--- a/kernel/include/string.h
+++ b/src/common/include/string.h
diff --git a/kernel/lib/mutex.c b/src/common/mutex.c
index cda8049..cda8049 100644
--- a/kernel/lib/mutex.c
+++ b/src/common/mutex.c
diff --git a/kernel/lib/printf.c b/src/common/printf.c
index 68e08d8..68e08d8 100644
--- a/kernel/lib/printf.c
+++ b/src/common/printf.c
diff --git a/kernel/lib/slab_alloc.c b/src/common/slab_alloc.c
index 714c49f..714c49f 100644
--- a/kernel/lib/slab_alloc.c
+++ b/src/common/slab_alloc.c
diff --git a/kernel/lib/string.c b/src/common/string.c
index 9dce27b..9dce27b 100644
--- a/kernel/lib/string.c
+++ b/src/common/string.c
diff --git a/src/kernel/Makefile b/src/kernel/Makefile
new file mode 100644
index 0000000..3fc7e9c
--- /dev/null
+++ b/src/kernel/Makefile
@@ -0,0 +1,14 @@
+
+OBJ = core/loader.o core/kmain.o core/dbglog.o core/sys.o \
+	core/gdt.o core/idt.o core/interrupt.o core/context_switch.o core/thread.o \
+	core/frame.o core/paging.o core/region.o core/kmalloc.o
+
+LIB = ../common/common.lib
+
+CFLAGS = -I ./include -I ../common/include
+
+LDFLAGS = -T linker.ld -Xlinker -Map=kernel.map
+
+OUT = kernel.bin
+
+include ../rules.make
diff --git a/kernel/config.h b/src/kernel/config.h
index a0e59d3..a0e59d3 100644
--- a/kernel/config.h
+++ b/src/kernel/config.h
diff --git a/kernel/l0/context_switch.s b/src/kernel/core/context_switch.s
index 6738a03..6738a03 100644
--- a/kernel/l0/context_switch.s
+++ b/src/kernel/core/context_switch.s
diff --git a/kernel/l0/dbglog.c b/src/kernel/core/dbglog.c
index e042625..e042625 100644
--- a/kernel/l0/dbglog.c
+++ b/src/kernel/core/dbglog.c
diff --git a/kernel/l0/frame.c b/src/kernel/core/frame.c
index 489d010..489d010 100644
--- a/kernel/l0/frame.c
+++ b/src/kernel/core/frame.c
diff --git a/kernel/l0/gdt.c b/src/kernel/core/gdt.c
index eadde5f..eadde5f 100644
--- a/kernel/l0/gdt.c
+++ b/src/kernel/core/gdt.c
diff --git a/kernel/l0/idt.c b/src/kernel/core/idt.c
index 2f244e3..2f244e3 100644
--- a/kernel/l0/idt.c
+++ b/src/kernel/core/idt.c
diff --git a/kernel/l0/interrupt.s b/src/kernel/core/interrupt.s
index d40fff0..d40fff0 100644
--- a/kernel/l0/interrupt.s
+++ b/src/kernel/core/interrupt.s
diff --git a/kernel/l0/kmain.c b/src/kernel/core/kmain.c
index 826fa14..2169b7d 100644
--- a/kernel/l0/kmain.c
+++ b/src/kernel/core/kmain.c
@@ -2,6 +2,7 @@
 #include <config.h>
 #include <dbglog.h>
 #include <sys.h>
+#include <malloc.h>
 
 #include <gdt.h>
 #include <idt.h>
@@ -81,10 +82,10 @@ void kmalloc_test(void* kernel_data_end) {
 	dbg_print_region_info();
 	dbg_printf("Begin kmalloc test...\n");
 	const int m = 200;
-	uint16_t** ptr = kmalloc(m * sizeof(uint32_t));
+	uint16_t** ptr = malloc(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);
+		ptr[i] = (uint16_t*)malloc(s);
 		ASSERT((void*)ptr[i] >= kernel_data_end && (size_t)ptr[i] < 0xFFC00000);
 		*ptr[i] = ((i * 211) % 1024);
 	}
@@ -94,9 +95,9 @@ void kmalloc_test(void* kernel_data_end) {
 		for (int j = i; j < m; j++) {
 			ASSERT(*ptr[j] == (j * 211) % 1024);
 		}
-		kfree(ptr[i]);
+		free(ptr[i]);
 	}
-	kfree(ptr);
+	free(ptr);
 	dbg_printf("Kmalloc test OK.\n");
 	dbg_print_region_info();
 }
diff --git a/kernel/l0/kmalloc.c b/src/kernel/core/kmalloc.c
index e356ada..e15572a 100644
--- a/kernel/l0/kmalloc.c
+++ b/src/kernel/core/kmalloc.c
@@ -27,7 +27,7 @@ static slab_type_t slab_sizes[] = {
 };
 
 static mem_allocator_t *kernel_allocator = 0;
-STATIC_MUTEX(kmalloc_mutex);
+STATIC_MUTEX(malloc_mutex);
 
 void kmalloc_setup() {
 	kernel_allocator =
@@ -35,18 +35,18 @@ void kmalloc_setup() {
 										region_free_unmap_free);
 }
 
-void* kmalloc(size_t sz) {
+void* malloc(size_t sz) {
 	void* res = 0;
 
-	mutex_lock(&kmalloc_mutex);
+	mutex_lock(&malloc_mutex);
 	res = slab_alloc(kernel_allocator, sz);
-	mutex_unlock(&kmalloc_mutex);
+	mutex_unlock(&malloc_mutex);
 
 	return res;
 }
 
-void kfree(void* ptr) {
-	mutex_lock(&kmalloc_mutex);
+void free(void* ptr) {
+	mutex_lock(&malloc_mutex);
 	slab_free(kernel_allocator, ptr);
-	mutex_unlock(&kmalloc_mutex);
+	mutex_unlock(&malloc_mutex);
 }
diff --git a/kernel/l0/loader.s b/src/kernel/core/loader.s
index 447d82d..447d82d 100644
--- a/kernel/l0/loader.s
+++ b/src/kernel/core/loader.s
diff --git a/kernel/l0/paging.c b/src/kernel/core/paging.c
index 683abe6..e60ca53 100644
--- a/kernel/l0/paging.c
+++ b/src/kernel/core/paging.c
@@ -5,7 +5,7 @@
 #include <region.h>
 #include <mutex.h>
 #include <thread.h>
-#include <kmalloc.h>
+#include <malloc.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))
@@ -233,7 +233,7 @@ pagedir_t *create_pagedir() {
 	pd_phys = frame_alloc(1);
 	if (pd_phys == 0) goto error;
 
-	pd = (pagedir_t*)kmalloc(sizeof(pagedir_t));
+	pd = (pagedir_t*)malloc(sizeof(pagedir_t));
 	if (pd == 0) goto error;
 
 	temp = region_alloc(PAGE_SIZE, 0, 0);
@@ -263,7 +263,7 @@ pagedir_t *create_pagedir() {
 
 	error:
 	if (pd_phys != 0) frame_free(pd_phys, 1);
-	if (pd != 0) kfree(pd);
+	if (pd != 0) free(pd);
 	if (temp != 0) region_free(temp);
 	return 0;
 }
@@ -290,7 +290,7 @@ void delete_pagedir(pagedir_t *pd) {
 	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);
+	free(pd);
 
 	return;
 }
diff --git a/kernel/l0/region.c b/src/kernel/core/region.c
index 3127048..3127048 100644
--- a/kernel/l0/region.c
+++ b/src/kernel/core/region.c
diff --git a/kernel/l0/sys.c b/src/kernel/core/sys.c
index 2b77463..2b77463 100644
--- a/kernel/l0/sys.c
+++ b/src/kernel/core/sys.c
diff --git a/kernel/l0/thread.c b/src/kernel/core/thread.c
index 0f5c209..7f0bb5b 100644
--- a/kernel/l0/thread.c
+++ b/src/kernel/core/thread.c
@@ -1,5 +1,5 @@
 #include <thread.h>
-#include <kmalloc.h>
+#include <malloc.h>
 #include <dbglog.h>
 #include <idt.h>
 
@@ -113,12 +113,12 @@ static void run_thread(void (*entry)(void*), void* data) {
 	ASSERT(false);
 }
 thread_t *new_thread(entry_t entry, void* data) {
-	thread_t *t = (thread_t*)kmalloc(sizeof(thread_t));
+	thread_t *t = (thread_t*)malloc(sizeof(thread_t));
 	if (t == 0) return 0;
 
 	void* stack = region_alloc(KPROC_STACK_SIZE, "Stack", 0);
 	if (stack == 0) {
-		kfree(t);
+		free(t);
 		return 0;
 	}
 
@@ -126,7 +126,7 @@ thread_t *new_thread(entry_t entry, void* data) {
 		uint32_t f = frame_alloc(1);
 		if (f == 0) {
 			region_free_unmap_free(stack);
-			kfree(t);
+			free(t);
 			return 0;
 		}
 		pd_map_page(i, f, true);
diff --git a/src/kernel/include/config.h b/src/kernel/include/config.h
new file mode 120000
index 0000000..93307d9
--- /dev/null
+++ b/src/kernel/include/config.h
@@ -0,0 +1 @@
+../config.h
\ No newline at end of file
diff --git a/kernel/include/dbglog.h b/src/kernel/include/dbglog.h
index 2f670e8..8bf6962 100644
--- a/kernel/include/dbglog.h
+++ b/src/kernel/include/dbglog.h
@@ -1,9 +1,8 @@
 #pragma once
 
 #include <config.h>
+#include <debug.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/src/kernel/include/frame.h
index 9ffafb3..9ffafb3 100644
--- a/kernel/include/frame.h
+++ b/src/kernel/include/frame.h
diff --git a/kernel/include/gdt.h b/src/kernel/include/gdt.h
index a62d0db..a62d0db 100644
--- a/kernel/include/gdt.h
+++ b/src/kernel/include/gdt.h
diff --git a/kernel/include/idt.h b/src/kernel/include/idt.h
index 8e84cea..8e84cea 100644
--- a/kernel/include/idt.h
+++ b/src/kernel/include/idt.h
diff --git a/kernel/include/kmalloc.h b/src/kernel/include/kmalloc.h
index a409865..d4a9272 100644
--- a/kernel/include/kmalloc.h
+++ b/src/kernel/include/kmalloc.h
@@ -8,7 +8,4 @@
 
 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/src/kernel/include/multiboot.h
index 581337a..581337a 100644
--- a/kernel/include/multiboot.h
+++ b/src/kernel/include/multiboot.h
diff --git a/kernel/include/paging.h b/src/kernel/include/paging.h
index 44014a2..44014a2 100644
--- a/kernel/include/paging.h
+++ b/src/kernel/include/paging.h
diff --git a/src/kernel/include/process.h b/src/kernel/include/process.h
new file mode 100644
index 0000000..00ed1d7
--- /dev/null
+++ b/src/kernel/include/process.h
@@ -0,0 +1,43 @@
+#pragma once
+
+// Things described in this file are essentially a public interface
+// All implementation details are hidden in process.c
+
+#include <thread.h>
+
+#include <hashtbl.h>
+#include <buffer.h>
+
+#define PW_NOT_WAITING		0
+#define PW_WAIT_ANY_MSG		1
+#define PW_WAIT_MSG_ON_CHAN	2
+
+#define PROCESS_MAILBOX_SIZE 42
+
+typedef int chan_id_t;
+
+typedef struct chan_pair {
+	chan_id_t fst, snd;
+} chan_pair_t;
+
+typedef struct message {
+	buffer_t *data;
+	chan_id_t chan_id;
+} message_t;
+
+struct process;
+typedef struct process process_t;
+
+process_t *new_process(entry_t entry, void* data, chan_pair_t *give_chans);
+
+chan_pair_t new_chan();		// not used very often, but still usefull
+chan_id_t unbox_chan(chan_id_t chan, chan_id_t subchan);
+void detach_chan(chan_id_t chan);		// chan ID is freed
+
+int send_message(chan_id_t chan, buffer_t *msg);	// nonnull on error (recipient queue is full)
+
+size_t await_message();		// returns the size of the first message to come
+size_t await_message_on_chan(chan_id_t chan);		// returns the size of the first message to come
+message_t get_message();	// gets the first message in the queue (or nothing when queue is empty)
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/kernel/include/region.h b/src/kernel/include/region.h
index 1fef582..1fef582 100644
--- a/kernel/include/region.h
+++ b/src/kernel/include/region.h
diff --git a/kernel/include/sys.h b/src/kernel/include/sys.h
index c8721ec..29735fa 100644
--- a/kernel/include/sys.h
+++ b/src/kernel/include/sys.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <debug.h> 		// common header
 #include <config.h>
 
 static inline void outb(uint16_t port, uint8_t value) {
@@ -26,11 +27,6 @@ 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")
 
 
diff --git a/kernel/include/thread.h b/src/kernel/include/thread.h
index 757ba00..757ba00 100644
--- a/kernel/include/thread.h
+++ b/src/kernel/include/thread.h
diff --git a/kernel/linker.ld b/src/kernel/linker.ld
index 1203950..1203950 100644
--- a/kernel/linker.ld
+++ b/src/kernel/linker.ld
diff --git a/src/kernel/user/process.c b/src/kernel/user/process.c
new file mode 100644
index 0000000..7519dae
--- /dev/null
+++ b/src/kernel/user/process.c
@@ -0,0 +1,30 @@
+#include <mutex.h>
+#include <process.h>
+
+typedef struct process {
+	thread_t *thread;
+	int pid;
+
+	mutex_t com_mutex;
+
+	hashtbl_t *chans;
+	chan_id_t next_chan_id;
+
+	message_t mbox[PROCESS_MAILBOX_SIZE];
+	int mbox_size;	// number of messages in queue
+	int mbox_first;	// first message in queue (circular buffer)
+
+	// a process can be in several waiting states :
+	// - wait for any message
+	// - wait for a message on a particular channel
+	//   in this case, if a message is pushed on this particular channel,
+	//	 then it is put in front of the queue, so that it is the next message read
+	//	 (it is guaranteed that doing await_message_on_chan() immediately followed by get_message()
+	//   gets the message whose size was returned by await_...)
+	int wait_state;
+	chan_id_t wait_chan_id;		// when waiting for a message on a particular channel
+} process_t;
+
+int push_message(process_t *proc, message_t msg);		// nonnull on error (process queue is full)
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/src/rules.make b/src/rules.make
new file mode 100644
index 0000000..e3840dd
--- /dev/null
+++ b/src/rules.make
@@ -0,0 +1,34 @@
+
+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 += -ffreestanding -O2 -nostdlib -lgcc
+
+all: $(OUT)
+
+%.bin: $(OBJ)
+	$(LD) $(LDFLAGS) -o $@ $^ $(LIB)
+
+%.lib: $(OBJ)
+	$(LD) $(LDFLAGS) -r -o $@ $^ $(LIB)
+
+%.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/lib_tests/Makefile b/src/tests/Makefile
index 4a21edf..4a21edf 100644
--- a/kernel/lib_tests/Makefile
+++ b/src/tests/Makefile
diff --git a/kernel/lib_tests/slab_test.c b/src/tests/slab_test.c
index 747c785..747c785 100644
--- a/kernel/lib_tests/slab_test.c
+++ b/src/tests/slab_test.c