debug: Implement parsing of register names

rom/debug.asm

@@ -6,8 +6,7 @@ bssvec:	equ 0xB6
 
 	db 0x55, 0xAA
 	db 0x00
-	jmp init
-	nop
+	jmp near init
 
 	times (0x18 - ($-$$)) db 0
 	dw 0
@@ -58,6 +57,8 @@ init:	push ds
 	pop ds
 	retf
 
+	%include "debug/parse.asm"
+
 	; Print AL
 space:	mov al, ' '
 putc:	xor bx, bx
@@ -65,17 +66,21 @@ putc:	xor bx, bx
 	int 0x10
 	ret
 
-	; Print CS:SI
-puts:	push ds
+	; Print code string CS:SI
+putcs:	push ds
 	push cs
 	pop ds
-.loop:	lodsb
+	call putds
+	pop ds
+	ret
+
+	; Print data string DS:SI
+putds:	lodsb
 	test al, al
 	jz .ret
 	call putc
-	jmp .loop
-.ret:	pop ds
-	ret
+	jmp putds
+.ret:	ret
 
 crlf:	mov al, 0x0A
 	call putc
@@ -106,6 +111,47 @@ print16:
 .noadj:	int 0x10
 	ret
 
+getc:	xor ax, ax
+	int 0x16
+	test al, al
+	jz getc
+	ret
+
+read:	mov di, cmdbuf
+.loop:	call getc
+	cmp al, 0x03
+	je .can
+	cmp al, 0x0D
+	je .enter
+	cmp al, 0x08
+	je .bs
+	cmp di, cmdbuf+cmdlen-1
+	jnc .loop
+	stosb
+	mov ah, 0x0e
+	xor bx, bx
+	int 0x10
+	jmp .loop
+	ret
+.bs:	cmp di, cmdbuf
+	jbe .loop
+	xor bx, bx
+	mov ax, 0x0e08
+	int 0x10
+	mov al, 0x20
+	int 0x10
+	mov al, 0x08
+	int 0x10
+	dec di
+	jmp .loop
+.can:	xor al, al
+	stosb
+	stc
+	ret
+.enter:	xor al, al
+	stosb
+	ret
+
 int3entry:
 	; save DS and load bss segment from IVT
 	push ds
@@ -143,7 +189,7 @@ int3entry:
 
 loop:	; show prompt
 	mov al, '-'
-	int 0x10
+	call putc
 	; read data
 	call read
 	pushf
@@ -179,54 +225,11 @@ return:	; restore stack pointer
 	; final jump back
 	iret
 
-names:	; general purpose regs
-	db "AXCXDXBXSPBPSIDI"
-	; segment regs
-	db "ESCSSSDS"
-	; special regs
-	db "IPFL"
-fnames:	; control flags
-	db "++++ODIT"
-	; status flags
-	db "SZ+A+P+C"
+	%include "debug/names.asm"
 
-getc:	xor ax, ax
-	int 0x16
-	test al, al
-	jz getc
-	ret
-
-read:	mov di, cmdbuf
-.loop:	call getc
-	cmp al, 0x03
-	je .can
-	cmp al, 0x0D
-	je .enter
-	cmp al, 0x08
-	je .bs
-	cmp di, cmdbuf+cmdlen
-	jnc .loop
-	stosb
-	mov ah, 0x0e
-	xor bx, bx
-	int 0x10
-	jmp .loop
-	ret
-.bs:	cmp di, cmdbuf
-	jbe .loop
-	xor bx, bx
-	mov ax, 0x0e08
-	int 0x10
-	mov al, 0x20
-	int 0x10
-	mov al, 0x08
-	int 0x10
-	dec di
-	jmp .loop
-.can:	stc
-.enter:	ret
-
-runcmd:	mov al, [cmdbuf]
+	; Expects DI to mark end of command
+runcmd:	mov si, cmdbuf
+	lodsb
 	cmp al, 'g'
 	je cmd_g
 	cmp al, 'r'
@@ -235,12 +238,12 @@ runcmd:	mov al, [cmdbuf]
 	je cmd_t
 	cmp al, '?'
 	je cmd_?
-	mov al, '?'
+cerr:	mov al, '?'
 	call putc
 	jmp crlf
 
 cmd_?:	mov si, .txt
-	jmp puts
+	jmp putcs
 .txt:	db "g       Go", 0x0A, 0x0D
 	db "r       Print register values", 0x0A, 0x0D
 	db "t       Single-Step", 0x0A, 0x0D
@@ -249,7 +252,15 @@ cmd_?:	mov si, .txt
 cmd_g:	and word [reg_fl+1], 0xfe
 	jmp return
 
-cmd_r:	jmp printregs
+cmd_r:	cmp di, si
+	je printregs
+	call eat_register
+	jc .err
+	mov dx, si
+	call print16
+	ret
+.err:	mov di, eat_register.emsg
+	jmp parse_error
 
 cmd_t:	or word [reg_fl+1], 0x03
 	jmp return
@@ -260,7 +271,7 @@ printregs:
 	mov ah, 0x0e
 	mov si, reg_ax
 .loop:	push cx
-	mov dx, [cs:si+names]
+	mov dx, [cs:si+rnames]
 	lodsw
 	call printreg
 	pop cx