diff options
| author | Kartik K. Agaram <vc@akkartik.com> | 2021-06-29 22:26:08 -0700 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2021-06-29 22:26:08 -0700 |
| commit | eba4e7af247ce45ea43edaf912f0a7ee4177e2d3 (patch) | |
| tree | dd04021a8f023da138bac73538551818f3d00496 /boot.subx | |
| parent | 3df5232ca46a76bca012e575297cbfb93753125d (diff) | |
| download | mu-eba4e7af247ce45ea43edaf912f0a7ee4177e2d3.tar.gz | |
move timer handler to boot.subx
Diffstat (limited to 'boot.subx')
| -rw-r--r-- | boot.subx | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/boot.subx b/boot.subx index 287c6877..2a896a97 100644 --- a/boot.subx +++ b/boot.subx @@ -302,11 +302,11 @@ idt_start: # https://wiki.osdev.org/index.php?title=Interrupts&oldid=25102#Default_PC_Interrupt_Vector_Assignment # entry 8: https://wiki.osdev.org/Programmable_Interval_Timer - null-interrupt-handler/imm16 # target[0:16] + timer-interrupt-handler/imm16 # target[0:16] 8/imm16 # segment selector (gdt_code) 00 # unused 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate - 0/imm16 # target[16:32] -- null-interrupt-handler must be within address 0x10000 + 0/imm16 # target[16:32] -- timer-interrupt-handler must be within address 0x10000 # entry 9: keyboard keyboard-interrupt-handler/imm16 # target[0:16] @@ -342,7 +342,7 @@ idt_start: == code -null-interrupt-handler: +timer-interrupt-handler: # prologue fa/disable-interrupts 60/push-all-registers @@ -351,13 +351,35 @@ null-interrupt-handler: b0/copy-to-al 0x20/imm8 e6/write-al-into-port 0x20/imm8 31/xor %eax 0/r32/eax -$null-interrupt-handler:end: + # ecx = *Timer-current-color + 8b/-> *Timer-current-color 1/r32/ecx + # update *Timer-current-color + 81 0/subop/add *Timer-current-color 0x01010101/imm32 + # eax = *Video-memory + 0x1200 (a few rows down from top, around middle of screen) + 8b/-> *Video-memory-addr 0/r32/eax + 05/add-to-eax 0x1200/imm32 + 89/copy *eax 1/r32/ecx + # eax += 0x400 + 05/add-to-eax 0x400/imm32 + 89/copy *eax 1/r32/ecx + # eax += 0x400 + 05/add-to-eax 0x400/imm32 + 89/copy *eax 1/r32/ecx + # eax += 0x400 + 05/add-to-eax 0x400/imm32 + 89/copy *eax 1/r32/ecx +$timer-interrupt-handler:epilogue: # epilogue 9d/pop-flags 61/pop-all-registers fb/enable-interrupts cf/return-from-interrupt +== data +Timer-current-color: + 0/imm32 + +== code keyboard-interrupt-handler: # prologue fa/disable-interrupts |