rdos/debug/main.asm

207 lines
2.9 KiB
NASM

cpu 8086
org 0x0000
rom:
db 0x55, 0xAA
.sectors:
db 0x00
.init:
mov dx, isr_debug
mov al, 0x1
call intr_register
mov al, 0x03
call intr_register
retf
.name:
db "rDebug", 0
times (0x18 - ($-$$)) db 0
.pcir_ptr:
dw 0
times (0x1A - ($-$$)) db 0
.pnp_ptr:
dw pnp
pnp:
db "$PnP"
.version:
db 1 ; version 1
.length:
db 2 ; 2 * 16 length
dw 0 ; offset of next header
db 0
.checksum:
db 0 ; checksum (filled by fix-rom)
dd 0 ; device identifier
dw 0 ; manufacturer string
dw rom.name ; product name string
db 0,0,0 ; device type string
db 0x20 ; device indicator, bit for "read cacheable" set
dw 0 ; boot connection vector
dw 0 ; boot disconnect vector
dw 0 ; bootstrap entry point
dw 0 ; reserved
dw 0
putc:
push bx
push cx
mov ah, 0x0e
mov bx, 0x0000
int 0x10
pop cx
pop bx
ret
intr_register:
; DI = AL * 4
mov ah, 4
mul ah
mov di, ax
; ES = 0
xor ax, ax
mov es, ax
; store offset
mov ax, dx
stosw
; store segment
mov ax, cs
stosw
ret
; Names for words in debug frame
; Two characters per word, 14 words total
debug_frame_names:
; general-purpose registers
db "AXCXDXBXSPBPSIDI"
; extra registers
db "DSESSSIPCSFL"
; Names for bits in debug_frame+26 (FL/Flags register)
; One character per bit, 16 bits total
debug_frame_flags:
db "++++ODIT"
db "SZ+A+P+C"
; Print a single register from the frame
; in SI frame offset for register
debug_frame_register_print:
mov bx, debug_frame_names
mov al, [cs:bx+si] ; first name char load
call putc
mov al, [cs:bx+si+1] ; second name char load
call putc
mov al, '='
call putc
mov ax, [ss:bp+si] ; value load
; prepare call to print_number
push bx
push cx
mov bx, 0x0010
mov cx, 3
call print_number_padded
pop cx
pop bx
mov al, ' '
call putc
ret
debug_frame_print:
mov si, 0
mov cx, 8
.reg1loop:
call debug_frame_register_print
add si, 2
loop .reg1loop
mov dx, [ss:bp+26]
mov di, debug_frame_flags
mov cx, 0x0010
.flag_loop:
mov al, [cs:di]
inc di
cmp al, '+'
je .next
test dx, 0x8000
jnz .write
mov al, '-'
.write:
call putc
.next:
sal dx, 1
loop .flag_loop
call printf
db 0x0A, 0x0D, 0
mov si, 16
mov cx, 3
.reg2loop:
call debug_frame_register_print
add si, 2
loop .reg2loop
mov ax, [bp+24]
mov bx, 0x0010
mov cx, 3
call print_number_padded
mov al, ':'
call putc
mov ax, [bp+22]
mov bx, 0x0010
mov cx, 3
call print_number_padded
call printf
db 0x0A, 0x0D, 0
ret
; this prints registers
; expect to be called as interrupt routine
isr_debug:
push ss
push es
push ds
push di
push si
push bp
push sp
push bx
push dx
push cx
push ax
mov bp, sp
mov [bp+08], bp
add WORD [bp+08], 28
call printf
db 0x0A, 0x0D, 0
call debug_frame_print
pop ax
pop cx
pop dx
pop bx
pop bp
pop bp
pop si
pop di
pop ds
pop es
pop ss
iret
%include "printf.inc"
align 512