diff options
| author | Kartik Agaram <vc@akkartik.com> | 2020-12-23 12:14:01 -0800 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2020-12-23 12:14:01 -0800 |
| commit | 63362f814bed6d48f1c83abc97cac8d46bd3de6f (patch) | |
| tree | 3064fa8955fe8dadff0d7631cbafeb4c349d895f | |
| parent | e60e0e06453788c769c457c64448fa5d00681707 (diff) | |
| download | mu-63362f814bed6d48f1c83abc97cac8d46bd3de6f.tar.gz | |
7390 - null interrupt tables
Looks like the reset loops stop if we create null handlers for the first 10 indexes in the IDT.
| -rw-r--r-- | apps/boot.hex | 80 |
1 files changed, 69 insertions, 11 deletions
diff --git a/apps/boot.hex b/apps/boot.hex index e526eea6..4ec143bd 100644 --- a/apps/boot.hex +++ b/apps/boot.hex @@ -205,8 +205,12 @@ e9 fb ff ff ff # loop forever 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 120: +# null interrupt handler: + cf # iret -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +# padding +# 121: + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 @@ -230,17 +234,71 @@ e9 fb ff ff ff # loop forever # offset 200 (address 0x7e00): interrupt descriptor table # 32 entries * 8 bytes each = 256 bytes (0x100) # idt_start: -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 -# offset 9: keyboard, following https://alex.dzyoba.com/blog/os-interrupts +# offset 0 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 1 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 2 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 3 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 4 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 5 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 6 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 7 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 8 + 20 7d # offset[0:16] + 08 00 # segment selector (gdt_code) + 00 # unused + 8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate + 00 00 # offset[16:32] + +# offset 9 20 7d # offset[0:16] 08 00 # segment selector (gdt_code) 00 # unused |