shell: add count arg to peek

Also, fix seek reversed endianness.
This commit is contained in:
Virgil Dupras 2019-04-14 11:54:18 -04:00
parent e4e7db8e23
commit 902c6a5dd3
2 changed files with 44 additions and 9 deletions

View File

@ -101,8 +101,8 @@ parseHexPair:
ld b, a ld b, a
inc hl inc hl
ld a, (hl) ld a, (hl)
;cp 0x21 cp 0x21
;jr c, .single ; special char? single digit jr c, .single ; special char? single digit
call parseHex call parseHex
jr c, .end ; error? jr c, .end ; error?
or b ; join left-shifted + new. we're done! or b ; join left-shifted + new. we're done!

View File

@ -166,22 +166,25 @@ shellPrintErr:
; When these commands are called, DE points to the first character of the ; When these commands are called, DE points to the first character of the
; command args. ; command args.
; Set memory pointer to the specified address. ; Set memory pointer to the specified address (word).
; Example: seek 01fe ; Example: seek 01fe
shellSeek: shellSeek:
push af
push de push de
push hl push hl
ex de, hl ex de, hl
call parseHexPair call parseHexPair
jr c, .error jr c, .error
ld (SHELL_MEM_PTR), a ; z80 is little endian. in a "ld hl, (nn)" op, L is loaded from the
; first byte, H is loaded from the second
ld (SHELL_MEM_PTR+1), a
inc hl inc hl
inc hl inc hl
call parseHexPair call parseHexPair
jr c, .error jr c, .error
ld (SHELL_MEM_PTR+1), a ld (SHELL_MEM_PTR), a
jr .success jr .success
.error: .error:
@ -190,12 +193,12 @@ shellSeek:
jr .end jr .end
.success: .success:
ld a, (SHELL_MEM_PTR) ld a, (SHELL_MEM_PTR+1)
ld hl, SHELL_HEX_FMT ld hl, SHELL_HEX_FMT
call fmtHexPair call fmtHexPair
ld a, 2 ld a, 2
call printnstr call printnstr
ld a, (SHELL_MEM_PTR+1) ld a, (SHELL_MEM_PTR)
call fmtHexPair call fmtHexPair
ld a, 2 ld a, 2
call printnstr call printnstr
@ -204,23 +207,55 @@ shellSeek:
.end: .end:
pop hl pop hl
pop de pop de
pop af
ret ret
; peek byte where memory pointer points to aby display its value ; peek byte where memory pointer points to any display its value. If the
; optional numerical byte arg is supplied, this number of bytes will be printed
;
; Example: peek 2 (will print 2 bytes)
shellPeek: shellPeek:
push af push af
push bc
push de
push hl push hl
ld b, 1 ; by default, we run the loop once
ld a, (de)
cp 0
jr z, .success ; no arg? don't try to parse
ex de, hl
call parseHexPair
jr c, .error
cp 0
jr z, .error ; zero isn't a good arg, error
ld b, a ; loop the number of times specified in arg
jr .success
.error:
ld a, SHELL_ERR_BAD_ARGS
call shellPrintErr
jr .end
.success:
ld hl, (SHELL_MEM_PTR) ld hl, (SHELL_MEM_PTR)
ld a, (hl) .loop: ld a, (hl)
ex hl, de
ld hl, SHELL_HEX_FMT ld hl, SHELL_HEX_FMT
call fmtHexPair call fmtHexPair
ld a, 2 ld a, 2
call printnstr call printnstr
ex hl, de
inc hl
djnz .loop
call printcrlf call printcrlf
.end:
pop hl pop hl
pop de
pop bc
pop af pop af
ret ret