From 23771ca8a8d795ab58cdb3646fc54fbfdd08af65 Mon Sep 17 00:00:00 2001
From: Recolic Keghart <root@recolic.net>
Date: Mon, 8 Jun 2020 17:49:59 +0800
Subject: [PATCH] init
---
asm/Makefile | 6 ++++++
asm/{x16.asm => boot.asm} | 19 ++++++++++++++++---
asm/mbr_end.inc | 2 ++
asm/str.16.inc | 17 +++++++++++++++++
asm/str.32.inc | 20 ++++++++++++++++++++
asm/test.asm | 25 +++++++++++++++++++++----
boot.backup.c | 39 ---------------------------------------
7 files changed, 82 insertions(+), 46 deletions(-)
create mode 100644 asm/Makefile
rename asm/{x16.asm => boot.asm} (70%)
create mode 100644 asm/mbr_end.inc
create mode 100644 asm/str.16.inc
create mode 100644 asm/str.32.inc
delete mode 100644 boot.backup.c
diff --git a/asm/Makefile b/asm/Makefile
new file mode 100644
index 0000000..ce6142a
--- /dev/null
+++ b/asm/Makefile
@@ -0,0 +1,6 @@
+build:
+ nasm -f bin boot.asm -o boot.img
+
+run: build
+ qemu-system-x86_64 boot.img
+
diff --git a/asm/x16.asm b/asm/boot.asm
similarity index 70%
rename from asm/x16.asm
rename to asm/boot.asm
index 4321a91..b7d842e 100644
--- a/asm/x16.asm
+++ b/asm/boot.asm
@@ -1,7 +1,7 @@
[bits 16]
[org 0x7c00]
-jmp _enter_prot_mode
+jmp _init_prot_mode
gdt_begin:
@@ -36,7 +36,7 @@ gdt_desc:
CODE_SEG_OFFSET equ gdt_entry_1 - gdt_begin
DATA_SEG_OFFSET equ gdt_entry_2 - gdt_begin
-_enter_prot_mode:
+_init_prot_mode:
cli
lgdt [gdt_desc]
mov eax, cr0
@@ -46,6 +46,7 @@ _enter_prot_mode:
jmp CODE_SEG_OFFSET:_prot_begin
[bits 32]
+%include "./str.32.inc"
_prot_begin:
mov ax, DATA_SEG_OFFSET
mov ds, ax
@@ -56,8 +57,20 @@ _prot_begin:
mov ebp, 0x90000 ; 600KB free space here, until 0x7c00 + 0x200 byte (MBR sector 0)
mov esp, ebp
+ ;;;;;;;;;;;;;;;;;;;;;;;;;;;;; 32BIT PROTECTED MODE BEGIN ;;;;;;;;;;;;;;;;;;;;;;;;;;
+_dead_loop:
+ mov ebx, _motd_32
+ call println_vga
+ mov ebx, _motd_32p
+ call println_vga
+ jmp _dead_loop
+
+_motd_32:
+ db '----- CPU is in INTEL x86 protected mode now -----', 0x0
+_motd_32p:
+ db '+++++ CPU is in INTEL x86 protected mode now +++++', 0x0
-
+%include "./mbr_end.inc"
diff --git a/asm/mbr_end.inc b/asm/mbr_end.inc
new file mode 100644
index 0000000..97b1717
--- /dev/null
+++ b/asm/mbr_end.inc
@@ -0,0 +1,2 @@
+times 510-($-$$) db 0
+dw 0xaa55
diff --git a/asm/str.16.inc b/asm/str.16.inc
new file mode 100644
index 0000000..ce51edf
--- /dev/null
+++ b/asm/str.16.inc
@@ -0,0 +1,17 @@
+
+println_bios:
+ ; Arg0: addr in register bx
+ ; while true:
+ ; if [bx] != NULL:
+ ; print [bx]; ++bx
+ mov ah, 0x0e
+_loop_begin:
+ mov al, [bx]
+ cmp al, 0x0
+ je _loop_exit
+ int 0x10
+ inc bx
+ jmp _loop_begin
+_loop_exit:
+ ret
+
diff --git a/asm/str.32.inc b/asm/str.32.inc
new file mode 100644
index 0000000..5f8c933
--- /dev/null
+++ b/asm/str.32.inc
@@ -0,0 +1,20 @@
+
+VGA_BEGIN_ADDR equ 0xb8000
+println_vga:
+ ; Arg0: addr in register ebx
+ pusha
+ mov edx, VGA_BEGIN_ADDR
+ mov ah, 0x0f
+_loop_begin_1:
+ mov al, [ebx]
+ cmp al, 0x0
+ je _loop_exit_1
+ mov [edx], ax
+ inc ebx
+ add edx, 2
+ jmp _loop_begin_1
+_loop_exit_1:
+ popa
+ ret
+
+
diff --git a/asm/test.asm b/asm/test.asm
index 4e8d2f4..086200f 100644
--- a/asm/test.asm
+++ b/asm/test.asm
@@ -3,8 +3,9 @@
;
[org 0x7c00]
-mov bx, str
-call println_bios
+mov ebx, str
+call println_vga
+jmp $
println_bios:
; Arg0: addr in register bx
@@ -22,13 +23,29 @@ _loop_begin:
_loop_exit:
ret
+; [bits 32]
+VGA_BEGIN_ADDR equ 0xb8000
println_vga:
- ; Arg0: addr in register eax
+ ; Arg0: addr in register ebx
+ pusha
+ mov edx, VGA_BEGIN_ADDR
+ mov ah, 0x0f
+_loop_begin_1:
+ mov al, [ebx]
+ cmp al, 0x0
+ je _loop_exit_1
+ mov [edx], ax
+ inc ebx
+ add edx, 2
+ jmp _loop_begin_1
+_loop_exit_1:
+ popa
+ ret
+
str:
db 'This is Recolic!', 0x0
-jmp $
times 510-($-$$) db 0
dw 0xaa55
diff --git a/boot.backup.c b/boot.backup.c
deleted file mode 100644
index 5b0b903..0000000
--- a/boot.backup.c
+++ /dev/null
@@ -1,39 +0,0 @@
-
-asm ("jmp 0x14");
-
-//void print_char(char to_print) {
-// asm inline (
-// "mov $0x0e, %%ah\n\t"
-// "mov %0, %%al\n\t"
-// "int $0x10"
-// :
-// : "Ir" (to_print)
-// : "ax"
-// );
-//}
-//
-//void println(char *s) {
-// while(*s != 0) {
-// print_char(*s);
-// }
-//}
-
-
-
-void main() {
-_start_p:
- asm (
- "mov $0x0e, %ah\n\t"
- "mov $0x55, %al\n\t"
- "int $0x10"
- );
- //print_char('X');
- //println("Hello world!");
- //println("Recolic Booting OS HERE...");
-}
-
-asm (
-"jmp 0x-2\n\t"
-);
-
-
--
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