Import backup from 2003-08-13

gdt.inc

@@ -34,6 +34,20 @@ VESA_DATA equ $-gdt
 	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
 	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
 	db	0x00	;base  31:24
+VIDEO_TEXT equ $-gdt
+	dw	0x7FFF	;limit 15:0
+	dw	0x8000	;base  15:0
+	db	0x0B	;base  23:16
+	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
+	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
+	db	0x00	;base  31:24
+VIDEO_GRAPHICS equ $-gdt
+	dw	0xFFFF	;limit 15:0
+	dw	0x0000	;base  15:0
+	db	0x0A	;base  23:16
+	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
+	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
+	db	0x00	;base  31:24
 USER_CODE equ $-gdt
 	dw	0xffff	;limit 15:0
 	dw	0x0000	;base  15:0

idt.inc

@@ -1,10 +1,8 @@
 
-idt_entry:
+idtr:
-	dw	0		;offset 15:0
+	dw	49*8-1		;size of idt
-	dw	KERNEL_CODE	;base 15:0
+	dd	IDT		;address of idt
-	db	0		;0
+
-	db	0x8E		;[P][DPL][0][TYPE]
-	dw	0		;offset 31:16
 
 %macro isr_label 1
 isr_%1:

kernel.asm

@@ -5,51 +5,55 @@
 %define IDT	0x150000
 
 [global start]
-extern _isr
+[extern _isr]
+[extern _k_init]
 
 bits 32
 
 start:
-	call	cls
+	cli				;if they weren't already off
-
+	mov	edi, GDT
-	mov	esi, msg
+	mov	esi, gdt
-	mov	edi, 0xb8000
+	mov	ecx, gdt_end-gdt
-
+copy_gdt:
-msg_loop:
 	lodsb
-	or	al, al
-	jz	msg_done
 	stosb
-	mov	al, 15
+	loop	copy_gdt
-	stosb
-	jmp	msg_loop
 
-msg_done:
+	mov	edi, IDT		;destination
-
+	mov	esi, isr_0		;address of isr0
-	jmp	$
+	mov	edx, isr_1-isr_0	;distance between isr labels
-
+	mov	ecx, 49			;number of isrlabels
-cls:
+fill_idt:
-	push	eax
+	mov	ebx, esi
-	push	ecx
+	mov	ax, si
-	push	edi
+	stosw				;0 offset 15:0
-
+	mov	ax, KERNEL_CODE
-	mov	edi, 0xb8000
+	stosw				;2 selector 15:0
-	mov	ecx, 2000
+	mov	ax, 0x8E00
-	mov	eax, 0x0700
+	stosw				;4 [P][DPL][0][TYPE][0][0][0][0][0][0][0][0]
-cls_loop:
+	shr	esi, 16
-	stosw
+	mov	ax, si
-	loop	cls_loop
+	stosw				;6 offset 31:16
-
+	mov	esi, ebx
-	pop	edi
+	add	esi, edx
-	pop	ecx
+	loop	fill_idt
-	pop	eax
-
-	ret
-
-msg:
-	db	"This kernel is located at 0x100000! Aren't you glad?", 0
 
+	lgdt	[gdtr]			;load gdt
+	jmp	KERNEL_CODE:newgdtcontinue
+newgdtcontinue:
+	mov	ax, KERNEL_DATA
+	mov	es, ax
+	mov	ds, ax
+	mov	gs, ax
+	mov	fs, ax
+	mov	ss, ax
+	mov	esp, 0x1ffffc		;stack just under 2mb, moves downward
+	lidt	[idtr]			;load idt
 
+	jmp	_k_init
+	hlt				;halt processor when k_init is done
+	jmp	$			;shouldn't get here...	
 	
 %include "gdt.inc"
 %include "idt.inc"

kernel.c

@@ -1,4 +1,20 @@
 
+void isr(int num);
+void k_init();
+
+void k_init()
+{
+	char *vidmem = (char *) 0xB8000;
+	char welcome[] = "Welcome to HOS kernel. You are now in protected mode.";
+	char *chrptr = welcome;
+	while (*chrptr != 0)
+	{
+		*vidmem++ = *chrptr++;
+		*vidmem++ = 15;
+	}
+
+}
+
 void isr(int num)
 {
 

stage2.asm

@@ -243,6 +243,7 @@ vesa_good:
 	stosb
 	mov	al, bl
 	call	puthex
+	add	di, 4
 	cmp	bh, 2
 	jge	vesa_good2
 	xor	ax, ax