diff options
| -rw-r--r-- | entry.S | 8 | ||||
| -rw-r--r-- | include/bios.h | 1 | ||||
| -rw-r--r-- | main.c | 24 |
3 files changed, 33 insertions, 0 deletions
@@ -41,6 +41,14 @@ popl %fs .endm +ENTRY(bios_irq) + pushw %ax + mov $0x20, %al + out %al, $0x20 + popw %ax + IRET +ENTRY_END(bios_irq) + /* * fake interrupt handler, nothing can be faster ever */ diff --git a/include/bios.h b/include/bios.h index fcfc5ba..7232bef 100644 --- a/include/bios.h +++ b/include/bios.h @@ -32,6 +32,7 @@ extern bioscall void int15_handler(struct biosregs *regs); extern bioscall void e820_query_map(struct biosregs *regs); extern void bios_intfake(void); +extern void bios_irq(void); extern void bios_int10(void); extern void bios_int15(void); @@ -45,11 +45,34 @@ static void set_realmode_int(int vec, void *p) realmode_idt[vec * 2 + 1] = flat_to_seg16((uintptr_t) p); } +static void setup_pic(void) +{ + /* Send ICW1 (select OCW1 + will send ICW4) */ + outb(0x20, 0x11); + outb(0xa0, 0x11); + /* Send ICW2 (base irqs: 0x08-0x0f for irq0-7, 0x70-0x77 for irq8-15) */ + outb(0x21, 8); + outb(0xa1, 0x70); + /* Send ICW3 (cascaded pic ids) */ + outb(0x21, 0x04); + outb(0xa1, 0x02); + /* Send ICW4 (enable 8086 mode) */ + outb(0x21, 0x01); + outb(0xa1, 0x01); + /* Mask all irqs (except cascaded PIC2 irq) */ + outb(0x21, ~(1 << 2)); + outb(0xa1, ~0); +} + static void setup_idt(void) { int i; for (i = 0; i < 0x1f; i++) set_realmode_int(i, bios_intfake); + for (i = 8; i < 16; i++) + set_realmode_int(i, bios_irq); + for (i = 0x70; i < 0x78; i++) + set_realmode_int(i, bios_irq); set_realmode_int(0x10, bios_int10); set_realmode_int(0x15, bios_int15); } @@ -57,6 +80,7 @@ static void setup_idt(void) int main(void) { make_bios_writable(); + setup_pic(); setup_idt(); // extract_acpi(); // extract_e820(); |