fixed the interrupt gate descriptor setup

diff --git a/src/boot/boot2.asm b/src/boot/boot2.asm
index 40807ef..df2653c 100644 (file)
--- a/src/boot/boot2.asm
+++ b/src/boot/boot2.asm
@@ -63,7 +63,7 @@ gdt_lim: dw 23
 gdt_base: dd gdt
 
        align 4
-idt_lim: dw 111
+idt_lim: dw 2047
 idt_base: dd idt
 
        align 8
@@ -85,6 +85,7 @@ idt:  times 104 db 0
        dw 8
        dw 8f00h    ; type: trap, present, default
        dw 0
+       times 1944 db 0 ; enough space for 256 gates
 
 gpf_msg: db "GP fault "
 

diff --git a/src/intr.asm b/src/intr.asm
index 58ef37f..fdd06ef 100644 (file)
--- a/src/intr.asm
+++ b/src/intr.asm
@@ -12,8 +12,81 @@ GATE_PRESENT equ 8000h
        global init_intr
 init_intr:
        call init_pic
+       ; install trap handlers
+       set_trap 0, trap_entry_div
+       set_trap 1, trap_entry_debug
+       set_trap 2, trap_entry_nmi
+       set_trap 3, trap_entry_bp
+       set_trap 4, trap_entry_overflow
+       set_trap 5, trap_entry_bound
+       set_trap 6, trap_entry_ill
+       set_trap 7, trap_entry_nodev
+       set_trap 8, trap_entry_dfault
+       set_trap 9, trap_entry_copseg
+       set_trap 10, trap_entry_tss
+       set_trap 11, trap_entry_segpres
+       set_trap 12, trap_entry_stack
+       set_trap 13, trap_entry_prot
+       set_trap 14, trap_entry_page
+       set_trap 15, trap_entry_reserved
+       set_trap 16, trap_entry_fpu
+       set_trap 17, trap_entry_align
+       set_trap 18, trap_entry_mce
+       set_trap 19, trap_entry_sse
+
+       ; install dummy interrupt handlers for all IRQ vectors
+%assign i 0
+%rep 8
+       set_irq_vector i, dummy_intr_pic1
+       set_irq_vector i+8, dummy_intr_pic2
+%assign i i+1
+%endrep
        ret
 
+%macro trap_err 2
+       global trap_entry_%2
+trap_entry_%2:
+       push dword %1
+       jmp trap_entry_common
+%endmacro
+
+%macro trap_noerr 2
+       global trap_entry_%2
+trap_entry_%2:
+       push dword 0
+       push dword %1
+       jmp trap_entry_common
+%endmacro
+
+trap_entry_common:
+       pusha
+       ; do exception handling
+       popa
+       add esp, 8      ; remove error code and exception number from stack
+       iret
+       
+       trap_noerr 0, div
+       trap_noerr 1, debug
+       trap_noerr 2, nmi
+       trap_noerr 3, bp
+       trap_noerr 4, overflow
+       trap_noerr 5, bound
+       trap_noerr 6, ill
+       trap_noerr 7, nodev
+       trap_err 8, dfault
+       trap_noerr 9, copseg
+       trap_err 10, tss
+       trap_err 11, segpres
+       trap_err 12, stack
+       trap_err 13, prot
+       trap_err 14, page
+       trap_noerr 15, reserved
+       trap_noerr 16, fpu
+       trap_err 17, align
+       trap_noerr 18, mce
+       trap_noerr 19, sse
+
+
        global set_intr
 set_intr:
        push ebp
@@ -21,47 +94,38 @@ set_intr:
        push ebx
 
        mov ebx, [ebp + 8]
-       mov eax, GATE_TRAP
+       mov ax, GATE_TRAP
        cmp ebx, 32     ; determine if it's an IRQ or an exception (trap)
        jb .notirq
-       mov eax, GATE_INTR
+       mov ax, GATE_INTR
 .notirq:
-       shl ebx, 1
        lea ebx, [ebx * 8 + idt] ; ebx <- pointer to gate descriptor
-       ; type|dpl goes to the 3rd dword of the descriptor (dpl is 0)
-       or eax, (GATE_DEFAULT | GATE_PRESENT)
-       mov [ebx + 8], eax
-       ; address low 16bits go to the first dword of the descriptor
+       ; type|dpl goes to the 3rd word of the descriptor (dpl is 0)
+       or ax, (GATE_DEFAULT | GATE_PRESENT)
+       mov [ebx + 4], ax
+       ; address low 16bits go to the first word of the descriptor
        mov eax, [ebp + 12]
        mov [ebx], ax
-       ; address high 16bits go to the last dword of the descriptor
+       ; address high 16bits go to the last word of the descriptor
        shr eax, 16
-       mov [ebx + 12], eax
-       ; selector (kcode:1) goes to the second dword of the descriptor
-       mov dword [ebx + 4], 08h
-
-       ; install dummy interrupt handlers for all IRQ vectors
-%assign i 0
-%rep 8
-       set_irq_vector i, dummy_intr_pic1
-       set_irq_vector i+8, dummy_intr_pic2
-%assign i i+1
-%endrep
+       mov [ebx + 6], ax
+       ; selector (kcode:1) goes to the second word of the descriptor
+       mov word [ebx + 2], 08h
 
        pop ebx
        pop ebp
        ret
 
 dummy_intr_pic1:
-       push eax
+       pusha
        end_of_irq 0
-       pop eax
+       popa
        iret
 
 dummy_intr_pic2:
-       push eax
+       pusha
        end_of_irq 8
-       pop eax
+       popa
        iret
 
 ; PIC initialization command word 1 bits

diff --git a/src/intr.inc b/src/intr.inc
index a96b164..4bcc085 100644 (file)
--- a/src/intr.inc
+++ b/src/intr.inc
@@ -10,6 +10,12 @@ IRQ_OFFSET   equ 32
 %define IRQ_TO_INTR(x) ((x) + IRQ_OFFSET)
 %define INTR_TO_IRQ(x) ((x) - IRQ_OFFSET)
 
+%macro set_trap 2
+       push dword %2
+       push dword %1
+       call set_intr
+       add esp, 8
+%endmacro
 
 %macro set_irq_vector 2
        push dword %2