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ghaiklor/hello-world-without-libc.c

Last active April 20, 2019 14:54
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Print alphabet without libc
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hello-world-without-libc.c
extern void loader_main() {
for (int i = 0; i < 26; i++) {
char c = 0x41 + i;
asm(
"mov %0, %%al;"
"mov $0x0E, %%ah;"
"int $0x10;"
:
: "r" (c)
);
}
}
@JL2210
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JL2210 commented Apr 20, 2019 •
edited

Here's a way to do Hello, World! in BIOS (please update your blog, too):

void loader_main(void) {
        char string[] = "Hello, World!\r\n";
        int length = sizeof[string];
	for (int i = 0; i < length; i++) {
		asm(
			"mov %0, %%al;"
			"mov $0x0E, %%ah;"
			"int $0x10;"
			:
			: "r" (string[i])
		);
	}
}

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