diff options
Diffstat (limited to '01_exercise/bootloader.c')
| -rw-r--r-- | 01_exercise/bootloader.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/01_exercise/bootloader.c b/01_exercise/bootloader.c index 0260c82..850250d 100644 --- a/01_exercise/bootloader.c +++ b/01_exercise/bootloader.c @@ -3,21 +3,21 @@ asm(".code16gcc\njmp $0, $main"); /* space for additional code */ -void main(void) -{ - asm( - "mov $0x007, %%ebx;" - "mov $0xE4E, %%eax; int $0x10;" - "mov $0xE69, %%eax; int $0x10;" - "mov $0xE63, %%eax; int $0x10;" - "mov $0xE65, %%eax; int $0x10;" - "mov $0xE20, %%eax; int $0x10;" - "mov $0xE42, %%eax; int $0x10;" - "mov $0xE6F, %%eax; int $0x10;" - "mov $0xE6F, %%eax; int $0x10;" - "mov $0xE74, %%eax; int $0x10;" - "mov $0xE73, %%eax; int $0x10;" - "jmp .;" - ::: "eax", "ebx" +char WRITE_CHARACTER_TTY = 0x0E; +void put(char c) { + short command = WRITE_CHARACTER_TTY << 8 | c; + // volatile because there is no output, so the function might get optimized away + asm volatile("int $0x10;" + :: "a"(command) ); } + + +void main(void) +{ + put('h'); + put('e'); + put('l'); + put('l'); + put('o'); +} |