diff options
Diffstat (limited to 'asm/bootstrap.atk16')
| -rw-r--r-- | asm/bootstrap.atk16 | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/asm/bootstrap.atk16 b/asm/bootstrap.atk16 index 73165b9..29ed0ea 100644 --- a/asm/bootstrap.atk16 +++ b/asm/bootstrap.atk16 @@ -1,16 +1,33 @@ @let stack_segment 0x8000 @let vector_table 0x10 +@let terminal_addr 0xE000 +@let keyboard_addr 0xE001 @address vector_table - hlt_isr ; 0x10 ISR0 - hlt_isr ; 0x11 ISR1 - hlt_isr ; 0x12 ISR2 - hlt_isr ; 0x13 ISR3 + hlt_isr ; 0x10 ISR0 + hlt_isr ; 0x11 ISR1 + hlt_isr ; 0x12 ISR2 + keyboard_isr ; 0x13 ISR3 (keyboard) stack_segment ; 0x14 Stack address 0x0 ; 0x15 Interrupt PC address (IPCA) + terminal_addr ; 0x16 Terminal peripheral address + keyboard_addr ; 0x17 Keyboard peripheral address @label hlt_isr ldi 0x55 RE + hlt + +@label keyboard_isr + spu RA ; use RA, RB + spu RB + ldi 0x17 RA ; RA := 0x17 Keyboard peripheral address pointer + ldr RA RA ; RA := 0xE001 Keyboard peripheral address deref + ldr RA RA ; RA := <16-bit keyboard character code> from MMIO register + ldi 0x16 RB ; RB := 0x16 Terminal peripheral address pointer + ldr RB RB ; RB := 0xE000 Terminal peripheral address deref + str RA RB ; terminal <- character code + spo RB ; restore RA, RB + spo RA rti @label program_segment |