x01.0s.21: print "Loading..."，loading
x01.0s.21: print "Loading..."，loading
先把目標設低點，開機進入後，在屏幕上打印“Loading..."即可。由於要在 bochs 中運行，首先就是安裝 bochs。Oldlinux 中有相關資源，可自行下載。winxp 和 linux 的配置腳本如下：
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# for windows bochs config
megs : 32
romimage: file=$BXSHARE/BIOS-bochs-latest
vgaromimage: file=$BXSHARE/VGABIOS-lgpl-latest
floppya: 1_44="a.img", status=inserted
floppyb: 1_44="b.img", status=inserted
ata0-master: type=disk, path="c.img", cylinders=365, heads=16, spt=63
boot: a
mouse: enabled=0
winxp
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# for linux bochs config
display_library : sdl
megs : 32
romimage : file=/usr/share/bochs/BIOS-bochs-latest
vgaromimage : file=/usr/share/vgabios/vgabios.bin
floppya: 1_44="a.img", status=inserted
floppyb: 1_44="b.img", status=inserted
ata0-master: type=disk, path="c.img", cylinders=365, heads=16, spt=63
boot : a
mouse : enabled=0
keyboard_mapping : enabled=1, map=/usr/share/bochs/keymaps/sdl-pc-us.map
linux
當然，這只是作為參考。如是 winxp，建議直接在 bochs-sls1.0 中編譯，用 dd 寫入 /dev/fd1, 即 b.img；如是 ubuntu，我使用 eclipse，貪圖智能提示而已，本質並無區別。github 中的代碼為 Ubuntu 系統。由於要求簡單，代碼自然也簡單，分別為 makefile, boot/bootsect.s, tools/build.c 如下：
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# makefile
AS86 = as86 -0 -a
LD86 = ld86 -0
AS = as
LD = ld
LDFLAGS = -s -x -M
CC = gcc
CFLAGS = -Wall -O -fstrength-reduce -fomit-frame-pointer -nostdinc -Iinclude
CPP = gcc -E -nostdinc -Iinclude
ROOT_DEV = /dev/hd1
.c.s:
$(CC) $(CFLAGS) -S -o $*.s $<
.s.o:
$(AS) -c -o $*.o $<
.c.o:
$(CC) $(CFLAGS) -c -o $*.o $<
Image: boot/bootsect tools/build
tools/build boot/bootsect > Image
sync
boot/bootsect: boot/bootsect.s
$(AS86) -o boot/bootsect.o boot/bootsect.s
$(LD86) -o boot/bootsect boot/bootsect.o
tools/build: tools/build.c
gcc -o tools/build tools/build.c
makefile
![]()
! boot/bootsect.s
.text
entry start
start:
mov ax, #0x07c0
mov ds, ax
mov es, ax
mov ss, ax
mov sp, #0xff00
mov cx, #18
mov bx, #0x000c
mov bp, #msg
mov ax, #0x1301
int 0x10
die:
jmp die
msg:
.byte 13,10,13,10
.ascii "Loading..."
.byte 13,10,13,10
.org 510
.word 0xaa55
boot/bootsect.s
![]()
/*
* tools/build.c
*/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/fs.h>
#include <unistd.h>
#include <fcntl.h>
#define MINIX_HEADER 32
#define GCC_HEADER 1024
#define SYS_SIZE 0x2000
#define DEFAULT_MAJOR_ROOT 3
#define DEFAULT_MINOR_ROOT 1
#define SETUP_SECTS 4
void die(char* str)
{
fprintf(stderr, "%s\n", str);
exit(1);
}
int main(int argc, char** argv)
{
int i, id, c;
char buf[1024];
char major_root, minor_root;
if (argc == 5) {
} else {
major_root = DEFAULT_MAJOR_ROOT;
minor_root = DEFAULT_MINOR_ROOT;
}
fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root);
for (i = 0; i < sizeof buf; i++)
buf[i] = 0;
if ((id = open(argv[1], O_RDONLY, 0)) < 0)
die("Unable open bootsect");
if (read(id, buf, MINIX_HEADER) != MINIX_HEADER)
die("Unable read Minix header");
i = read(id, buf, sizeof buf);
fprintf(stderr, "bootsect is %d bytes.\n", i);
buf[508] = (char)major_root;
buf[509] = (char)minor_root;
if ((*(unsigned short*)(buf + 510)) != 0xaa55)
die("boot hasn't '0xaa55' flag.");
i = write(1, buf, 512);
if (i != 512)
die("write call failed.");
close(id);
return 0;
}
tools/build.c
效果圖如下：
源代碼：https://github.com/chinax01/Lab
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