7 files changed, 331 insertions, 0 deletions
diff --git a/src/stem/core/kmain.c b/src/stem/core/kmain.c
new file mode 100644
index 0000000..dbec8bd
--- /dev/null
+++ b/src/stem/core/kmain.c
@@ -0,0 +1,44 @@
+#include <types.h>
+#include "multiboot.h"
+#include "monitor.h"
+#include "sys.h"
+#include <task/idt.h>
+#include <task/timer.h>
+#include <task/task.h>
+#include <mem/gdt.h>
+#include <mem/paging.h>
+#include <mem/mem.h>
+
+void kmain_othertask(void *data) {
+	while(1) monitor_write("2task ");
+}
+
+void kmain_stage2(void *data) {
+	sti();
+	thread_new(current_thread->process, kmain_othertask, 0);
+	while (1) monitor_write("TASK1 ");
+}
+
+void kmain(struct multiboot_info_t* mbd, int32_t magic) {
+	size_t totalRam = 0;
+
+	mem_placementAddr = (size_t)&end;
+
+	monitor_clear();
+
+	if (magic != MULTIBOOT_BOOTLOADER_MAGIC) {
+		PANIC("wrong multiboot magic number.");
+	}
+
+	monitor_write("Grapes::Stem is booting\n");
+
+	idt_init();
+
+	totalRam = ((mbd->mem_upper + mbd->mem_lower) * 1024);
+	paging_init(totalRam);
+	gdt_init();
+	paging_cleanup();
+	kheap_init();
+	timer_init(20);
+	tasking_init(kmain_stage2, 0);
+}
diff --git a/src/stem/core/loader_.asm b/src/stem/core/loader_.asm
new file mode 100644
index 0000000..e1031b4
--- /dev/null
+++ b/src/stem/core/loader_.asm
@@ -0,0 +1,63 @@
+[GLOBAL loader]           ; making entry point visible to linker
+[EXTERN kmain]            ; kmain is defined in kmain.c
+
+STACKSIZE equ 0x4000                  ; that's 16k.
+ 
+; 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 .text
+align 4
+MultiBootHeader:
+   dd MAGIC
+   dd FLAGS
+   dd CHECKSUM
+ 
+section .setup
+loader:		;here, we load our false GDT, used for having the kernel in higher half
+	lgdt [trickgdt]
+	mov cx, 0x10;
+	mov ds, cx;
+	mov es, cx;
+	mov fs, cx;
+	mov gs, cx;
+	mov ss, cx;
+
+	jmp 0x08:higherhalf
+
+section .text
+higherhalf:		; now we're running in higher half
+
+   mov esp, stack+STACKSIZE           ; set up the stack
+   push eax                           ; pass Multiboot magic number
+   add ebx, 0xE0000000				  ; update the MB info structure so that it is in the new seg
+   push ebx                           ; pass Multiboot info structure
+
+   call  kmain                       ; call kernel proper
+
+   cli		; disable interupts
+hang:
+   hlt                                ; halt machine should kernel return
+   jmp   hang
+
+[section .setup]	; this is included in the .setup section, so that it thinks it is at 0x00100000
+
+trickgdt:		; our false GDT
+   dw gdt_end - gdt - 1		; gdt limit
+   dd gdt					; gdt base
+
+gdt:
+   dd 0, 0					; null GDT entry
+   db 0xFF, 0xFF, 0, 0, 0, 10011010b, 11001111b, 0x20	; kernel code segment
+   db 0xFF, 0xFF, 0, 0, 0, 10010010b, 11001111b, 0x20	; kernel data segment
+
+gdt_end:
+ 
+[section .bss]
+align 32
+stack:
+   resb STACKSIZE                     ; reserve 16k stack on a quadword boundary
diff --git a/src/stem/core/monitor.c b/src/stem/core/monitor.c
new file mode 100644
index 0000000..8c4744a
--- /dev/null
+++ b/src/stem/core/monitor.c
@@ -0,0 +1,90 @@
+#include "monitor.h"
+#include "sys.h"
+
+static int cursor_x = 0, cursor_y = 0;
+static uint16_t *video_memory = (uint16_t*)0xE00B8000;
+
+static void move_cursor() {
+	uint16_t cursor_location = cursor_y * 80 + cursor_x;
+	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 scroll() {
+	uint8_t attribute_byte = (0 /* black */ << 4) | (7/* white */ & 0x0F);
+	uint16_t blank = (attribute_byte << 8) | 0x20;
+
+	if (cursor_y >= 25) {
+		int i;
+		for (i = 0; i < 80*24; i++) {
+			video_memory[i] = video_memory[i+80];
+		}
+		for (i = 80*24; i < 80*25; i++) {
+			video_memory[i] = blank;
+		}
+		cursor_y = 24;
+	}
+}
+
+void monitor_put(char c) {
+	uint8_t fg = 7;	//White
+	uint8_t bg = 0; //Black
+
+	uint16_t attribute = (fg & 0x0F) | (bg << 4);
+	attribute = attribute << 8;
+
+	if (c == 0x08 && cursor_x) {	//Backspace
+		cursor_x--;
+	} else if (c == 0x09) {	//Tab
+		cursor_x = (cursor_x + 8) & ~(8 - 1);
+	} else if (c == '\r') {	//Carriage return
+		cursor_x = 0;
+	} else if (c == '\n') {	//New line
+		cursor_x = 0;
+		cursor_y++;
+	} else if (c >= ' ') {	//Any printable character
+		video_memory[cursor_y * 80 + cursor_x] = c | attribute;
+		cursor_x++;
+	}
+	if (cursor_x >= 80) {
+		cursor_x = 0;
+		cursor_y++;
+	}
+
+	scroll();
+	move_cursor();
+}
+
+void monitor_clear() {
+	uint8_t attribute_byte = (0 /* black */ << 4) | (15 /* white */ & 0x0F);
+	uint16_t blank = (attribute_byte << 8) | 0x20;
+
+	int i;
+
+	for (i = 0; i < 80*25; i++) {
+		video_memory[i] = blank;
+	}
+
+	cursor_x = 0; cursor_y = 0;
+	move_cursor();
+}
+
+void monitor_write(char *s) {
+	while (*s) {
+		monitor_put(*(s++));
+	}
+}
+
+void monitor_writeHex(uint32_t v) {
+	int i;
+
+	monitor_put('0'); monitor_put('x');
+	char hexdigits[] = "0123456789abcdef";
+
+	for (i = 0; i < 8; i++) {
+		monitor_put(hexdigits[v >> 28]);
+		v = v << 4;
+	}
+}
diff --git a/src/stem/core/monitor.h b/src/stem/core/monitor.h
new file mode 100644
index 0000000..3abe072
--- /dev/null
+++ b/src/stem/core/monitor.h
@@ -0,0 +1,12 @@
+#ifndef DEF_MONITOR_H
+#define DEF_MONITOR_H
+
+#include "types.h"
+
+void monitor_put(char c);
+void monitor_clear();
+void monitor_write(char *s);
+void monitor_writeHex(uint32_t v);
+
+#endif
+
diff --git a/src/stem/core/multiboot.h b/src/stem/core/multiboot.h
new file mode 100644
index 0000000..908274c
--- /dev/null
+++ b/src/stem/core/multiboot.h
@@ -0,0 +1,64 @@
+#ifndef HDR_MULTIBOOT
+#define HDR_MULTIBOOT
+#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;
+};
+
+#endif
+
diff --git a/src/stem/core/sys.c b/src/stem/core/sys.c
new file mode 100644
index 0000000..71d1c31
--- /dev/null
+++ b/src/stem/core/sys.c
@@ -0,0 +1,41 @@
+#include "sys.h"
+#include "monitor.h"
+
+void outb(uint16_t port, uint8_t value) {
+	asm volatile("outb %1, %0" : : "dN"(port), "a"(value));
+}
+
+void outw(uint16_t port, uint16_t value) {
+	asm volatile("outw %1, %0" : : "dN"(port), "a"(value));
+}
+
+uint8_t inb(uint16_t port) {
+	uint8_t ret;
+	asm volatile("inb %1, %0" : "=a"(ret) : "dN"(port));
+	return ret;
+}
+
+uint16_t inw(uint16_t port) {
+	uint16_t ret;
+	asm volatile("inw %1, %0" : "=a"(ret) : "dN"(port));
+	return ret;
+}
+
+void panic(char* message, char* file, int line) {
+	monitor_write(">> PANIC: >>");
+	monitor_write(message); monitor_write("<< in file "); monitor_write(file);
+	monitor_write("\nSystem halted T_T");
+	asm volatile("cli; hlt");
+}
+
+static uint32_t if_locks = 1;
+
+void cli() {
+	asm volatile("cli");
+	if_locks++;
+}
+
+void sti() {
+	if_locks--;
+	if (if_locks == 0) asm volatile("sti");
+}
diff --git a/src/stem/core/sys.h b/src/stem/core/sys.h
new file mode 100644
index 0000000..76e3560
--- /dev/null
+++ b/src/stem/core/sys.h
@@ -0,0 +1,17 @@
+#ifndef DEF_SYS_H
+#define DEF_SYS_H
+
+#include "types.h"
+
+void outb(uint16_t port, uint8_t value);
+void outw(uint16_t port, uint16_t value);
+uint8_t inb(uint16_t port);
+uint16_t inw(uint16_t port);
+
+#define PANIC(s) panic(s, __FILE__, __LINE__);
+void panic(char* message, char* file, int line);
+
+void sti();		//GLOBAL SYSTEM MUTEX
+void cli();
+
+#endif