initial commitHEADmaster

5 files changed, 170 insertions, 0 deletions

diff --git a/stage1/32bit.c b/stage1/32bit.c
new file mode 100644
index 0000000..1e4a7ef
--- /dev/null
+++ b/stage1/32bit.c
@@ -0,0 +1,22 @@
+#define STAGE1
+#include "stage1.h"
+
+#include <stddef.h>
+#include <stdint.h>
+#include <vga.h>
+#include <printk.h>
+#include <string.h>
+
+void centry(void)
+{
+	vga_setup(25,80);
+
+	uint8_t color = vga_color(0xF, 0);
+
+	write("Bootloader is set to 32-bit mode.", color);
+
+	while (1) {
+		asm ("cli");
+		asm ("hlt");
+	}
+}
diff --git a/stage1/32bit.o b/stage1/32bit.o
new file mode 100755
index 0000000..bd221e3
--- /dev/null
+++ b/stage1/32bit.o
diff --git a/stage1/entry.S b/stage1/entry.S
new file mode 100644
index 0000000..81390d9
--- /dev/null
+++ b/stage1/entry.S
@@ -0,0 +1,56 @@
+.intel_syntax noprefix
+
+.section .mbr, "ax"
+
+.extern _stack_start
+.extern _stack_end
+.extern centry
+
+.global _start
+.code16
+	
+_start:	
+	xor ax, ax
+	mov ds, ax
+	jmp 0x0:_entry
+
+_entry:
+	mov ah, 0x42
+	mov si, offset dap
+	
+	int 0x13
+
+	jc error
+
+	mov ah, 0x0E
+	mov al, 'S'
+	mov bh, 0x0
+	mov bl, 0x0
+
+	int 0x10
+
+	jmp 0x0:stage1_sector
+	
+	cli
+	hlt
+
+error:
+	mov ah, 0x0e
+	mov al, 'E'
+	mov bh, 0x0
+	mov bl, 0x0
+
+	int 0x10
+
+	cli
+	hlt
+
+.section .mbr_data, "aw"
+
+dap:
+	.byte 0x10
+	.byte 0
+	.word 14
+	.word 0x7e00
+	.word 0x0
+	.quad 1
diff --git a/stage1/stage1.S b/stage1/stage1.S
new file mode 100644
index 0000000..e11e36b
--- /dev/null
+++ b/stage1/stage1.S
@@ -0,0 +1,84 @@
+.intel_syntax noprefix
+.code16
+
+.extern _stack_start
+.extern _stack_end
+
+.global stage1_sector
+
+.section .stage1, "ax"
+
+stage1_sector:
+	xor ax, ax
+	
+	mov ah, 0x0e
+	mov al, 'C'
+	mov bh, 0x0
+	mov bl, 0x0
+
+	int 0x10
+	
+	cli
+
+	lgdt gdtr
+	
+	mov eax, cr0
+	or eax, (1 << 0)
+	mov cr0, eax
+
+	jmp 0x8:_32_start
+	
+	cli
+	hlt
+
+.code32
+_32_start:
+	mov eax, 0x10
+
+	mov ds, ax
+	mov ss, ax
+	mov es, ax
+	mov fs, ax
+	mov gs, ax
+	
+	jmp 0x8:_32_entry
+
+	cli
+	hlt
+	
+_32_entry:
+	mov eax, offset _stack_start
+	mov ebp, eax
+	mov eax, offset _stack_end
+	mov esp, eax 
+
+	call centry
+
+	cli
+	hlt
+
+.code16
+.section .stage1_ro, "aw"
+
+gdt:
+	.quad 0x0 // Null seg
+	
+	.word 0xFFFF // Code seg
+	.word 0x0000
+	.byte 0x0
+	.byte 0b10011011 // A=1 RW=1 DC=0 E=1 S=1 DPL=00 P=1
+	.byte 0b11001111
+	.byte 0x0000
+
+	.word 0xFFFF // Data Seg
+	.word 0x0000
+	.byte 0x0
+	.byte 0b10010011 // A=1 RW=1 DC=0 E=0 S=1 DPL=00 P=1
+	.byte 0b11001111
+	.byte 0x0000
+
+end_gdt:
+
+gdtr:
+	.word end_gdt - gdt - 1
+	.long gdt
diff --git a/stage1/stage1.h b/stage1/stage1.h
new file mode 100644
index 0000000..cf29acb
--- /dev/null
+++ b/stage1/stage1.h
@@ -0,0 +1,8 @@
+#ifndef STAGE1_H
+#define STAGE1_H
+
+#include <defs.h>
+
+void centry(void) BLSEC_TEXT;
+
+#endif