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Luke Street
34 lines
1.1 KiB
C
34 lines
1.1 KiB
C
#include "acpi.h"
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#include "ports.h"
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#define KBRD_INTRFC 0x64
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/* keyboard interface bits */
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#define KBRD_BIT_KDATA 0 /* keyboard data is in buffer (output buffer is empty) (bit 0) */
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#define KBRD_BIT_UDATA 1 /* user data is in buffer (command buffer is empty) (bit 1) */
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#define KBRD_IO 0x60 /* keyboard IO port */
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#define KBRD_RESET 0xFE /* reset CPU command */
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#define bit(n) (1<<(n))
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#define check_flag(flags, n) ((flags) & bit(n))
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// Not actually ACPI, but I'll get there eventually.
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_noreturn
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void reboot() {
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uint8_t temp;
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__asm__ volatile("cli"); /* disable all interrupts */
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/* Clear all keyboard buffers (output and command buffers) */
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do {
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temp = port_byte_in(KBRD_INTRFC); /* empty user data */
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if (check_flag(temp, KBRD_BIT_KDATA) != 0)
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port_byte_in(KBRD_IO); /* empty keyboard data */
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} while (check_flag(temp, KBRD_BIT_UDATA) != 0);
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port_byte_out(KBRD_INTRFC, KBRD_RESET); /* pulse CPU reset line */
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loop:
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__asm__ volatile("hlt"); /* if that didn't work, halt the CPU */
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goto loop; /* if a NMI is received, halt again */
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} |