lordtet
55d5823bde
Still need to document a lot of functions, but I cleaned up and explained a lot of the code via comments.
55 lines
1.6 KiB
ArmAsm
55 lines
1.6 KiB
ArmAsm
; Interrupts.s - Implementations of IA32 interrupts.
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;Let's make an interrupt pointer table so C can reference it and build the IDT.
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global isr_ptrs
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extern generic_isr_handler
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;By the time we get here, we actually have a rather consistent stack:
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; dword [Interrupt ID]
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; dword [Error code (0 if int has no error code field)]
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; dword [EIP]
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; dword [CS]
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; dword [EFLAGS]
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; We can pass this to C. First, we might want to push all of our registers or something.
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isr_common:
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pusha
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push esp ;Throwing a pointer to ESP in there for referencing the aforementioned stuff as a struct
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call generic_isr_handler
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add esp,4 ;Remove that esp ref from the stack
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popad ;restore our gp registers
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add esp,8 ;deallocate the error code from the stack before heading out
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iret
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;Macro for the isr: 1 argument for the interrupt ID
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%macro ISR_ENTRY 1
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;isr_int#
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isr_%1:
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cli
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;Small table of interrupts that don't have an error code associated, so we push a dummy for stack consistency.
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%if %1 = 8 || %1 = 10 || %1 = 11 || %1 = 12 || %1 = 13 || %1 = 14 || %1 = 17 || %1 = 21
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%else
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push dword 0
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%endif
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;This is us pushing the isr #, which is also just the interrupt ID. Useful later.
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push dword %1
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jmp isr_common
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%endmacro
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;This is to trigger the above macro once for every ISR.
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%assign j 0
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%rep 255
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ISR_ENTRY j
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%assign j j+1
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%endrep
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; Generate a table of pointers that point to each of our ISRs. This will be accessed from C to setup our IDT.
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isr_ptrs:
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%assign i 0
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%rep 255
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dd isr_ %+ i
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%assign i i+1
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%endrep
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isr_ptrs_end:
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