diff options
| author | Kartik K. Agaram <vc@akkartik.com> | 2021-03-28 08:22:05 -0700 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2021-03-28 08:30:57 -0700 |
| commit | dfda825e55439b6ab89e4715913ee749d4e27b80 (patch) | |
| tree | 54f45100a6db627ca28a6f7a8b77e3a3455e51e0 /boot.subx | |
| parent | ad53022489ad22dea8afd534cd4a05ccf26a6cec (diff) | |
| download | mu-dfda825e55439b6ab89e4715913ee749d4e27b80.tar.gz | |
always acknowledge enabled interrupts
Now we can start enabling the timer interrupt. It doesn't do anything yet, but keyboard continues to work.
Diffstat (limited to 'boot.subx')
| -rw-r--r-- | boot.subx | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/boot.subx b/boot.subx index 6b95b9f9..21899dbc 100644 --- a/boot.subx +++ b/boot.subx @@ -211,8 +211,8 @@ initialize_32bit_mode: # Reference: # https://wiki.osdev.org/Exceptions - # enable keyboard IRQ (1) - b0/copy-to-al 0xfd/imm8 # disable mask for IRQ1 + # enable timer IRQ0 and keyboard IRQ1 + b0/copy-to-al 0xfc/imm8 # disable mask for IRQ0 and IRQ1 e6/write-al-into-port 0x21/imm8 fb/enable-interrupts @@ -300,6 +300,21 @@ idt_start: == code null-interrupt-handler: + # prologue + # Don't disable interrupts; the timer has the highest priority anyway, + # and this interrupt triggers extremely frequently. + fa/disable-interrupts + 60/push-all-registers + 9c/push-flags + # acknowledge interrupt + b0/copy-to-al 0x20/imm8 + e6/write-al-into-port 0x20/imm8 + 31/xor %eax 0/r32/eax +$null-interrupt-handler:epilogue: + # epilogue + 9d/pop-flags + 61/pop-all-registers + fb/enable-interrupts cf/return-from-interrupt keyboard-interrupt-handler: |