编写一个简单的引导加载程序HelloWorld - 错误函数打印字符串 [英] Write a simple Bootloader HelloWorld - Error function print string
问题描述
当我调用一个只打印hello world的函数时,我可以做到这一点,但当我调用一个函数打印一个特定的字符串时,什么都没有发生。
对于它,我使用两个文件。第一个是boot.ld,第二个是boot.cpp(它也可以在C中用boot.c工作)。
首先,我从我的磁盘创建软盘终端:
lockquote
dd if = / dev / zero of = floppy.img bs = 512 count = 2880
其次,我编译代码(boot.cpp和boot.ld):
gcc -c -g -Os -m64 -wreestanding -Wall -Werror boot.cpp -o boot.o
ld -static -Tboot.ld -nostdlib --nmagic -o boot.elf boot.o
$ b $ objcopy -O binary boot.elf boot.bin
最后,我将boot.bin添加到floppy.img中:
if if = boot.bin of = floppy.img
现在我们只需要从VirtualBox的存储面板添加软盘并启动我们的虚拟机。
源代码
from: 有问题的源代码 boot.cpp(或boot.c) 输出: 为什么输出为空? 我的函数出了什么问题? 我忘记了什么? 感谢您的帮助。 感谢@ I try to create a simple bootloader which print "hello world". I can do it when I call a function which only print "hello world", but when I call a function to print a specific string, nothing is happening. For it, I use two files. The first one is boot.ld and the second is boot.cpp (it also work in C with boot.c). Firstly, I create the floppy disk from my terminal: dd if=/dev/zero of=floppy.img bs=512 count=2880 Secondly, I compile the code (boot.cpp and boot.ld): gcc -c -g -Os -m64 -ffreestanding -Wall -Werror boot.cpp -o boot.o ld -static -Tboot.ld -nostdlib --nmagic -o boot.elf boot.o objcopy -O binary boot.elf boot.bin Lastly, I add boot.bin into floppy.img: dd if=boot.bin of=floppy.img Now we just need to add the floppy from the storage panel of VirtualBox and launch our Virtual Machine. The source code from: http://www.codeproject.com/Articles/664165/Writing-a-boot-loader-in-Assembly-and-C-Part boot.ld boot.cpp (or boot.c) Output: The bugged source code boot.cpp (or boot.c) Output: Why the output is empty? What is wrong in my function? I have forget something? Thanks for your help. Thanks to @MichaelPetch for this answer. Source code: boot.ld boot.cpp Also here: http://pastebin.com/6NV3UMjE Compile: gcc -c -g -O0 -m32 -ffreestanding -Wall -Werror boot.cpp -o boot.o ld -melf_i386 -static -Tboot.ld -nostdlib --nmagic -o boot.elf boot.o objcopy -O binary boot.elf boot.bin dd if=boot.bin of=floppy.img conv=notrunc Output: 这篇关于编写一个简单的引导加载程序HelloWorld - 错误函数打印字符串的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
void cout(const char * str);
void main()
{
cout(hello world);
}
void cout(const char * str)
{
while(* str)
{
__asm__ __volatile__(int $ 0 x10::a(0x0e00 | * str),b(0x0007));
++ str;
}
}
ENTRY(main);
SECTIONS
{
. = 0x7C00;
.text : AT(0x7C00)
{
*(.text);
}
.sig : AT(0x7DFE)
{
SHORT(0xaa55);
}
}
void cout();
void main()
{
cout();
}
void cout()
{
__asm__ __volatile__("movb $'h' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'e' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'l' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'l' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'o' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $' ' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'w' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'o' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'r' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'l' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
__asm__ __volatile__("movb $'d' , %al\n");
__asm__ __volatile__("movb $0x0e, %ah\n");
__asm__ __volatile__("int $0x10\n");
}
void cout(const char* str);
void main()
{
cout("hello world");
}
void cout(const char* str)
{
while(*str)
{
__asm__ __volatile__ ("int $0x10" : : "a"(0x0e00 | *str), "b"(0x0007));
++str;
}
}
ENTRY(main);
SECTIONS
{
. = 0x7C00;
.text : AT(0x7C00)
{
*(.text);
}
.sig : AT(0x7DFE)
{
SHORT(0xaa55);
}
}
asm(".code16gcc");
__asm__("jmpl $0x0000, $main\n");
void cout(const char* str);
void main()
{
__asm__ __volatile__ ("xor %ax, %ax\n");
__asm__ __volatile__ ("mov %ax, %ds\n");
cout("Hello World");
__asm__ __volatile__("cli\n");
__asm__ __volatile__("hlt\n");
}
void cout(const char* str)
{
while(*str)
{
__asm__ __volatile__("int $0x10" : : "a"(0x0e00 | *str), "b"(0x0007));
++str;
}
}