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make mptr print the current memory pointer when called with no arguments

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This commit is contained in:
Valentin Lenhart 2019-10-21 17:32:00 +02:00
parent c230856f09
commit 5a826de1ee
1 changed files with 8 additions and 2 deletions
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10
kernel/shell.asm
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@ -221,13 +221,18 @@ shellPrintErr:
; directive *just* after your '.inc "shell.asm"'. Voila! ; directive *just* after your '.inc "shell.asm"'. Voila!
; ;
; Set memory pointer to the specified address (word). ; Set memory pointer to the specified address (word) or print the current value.
; Example: mptr 01fe ; Example: mptr 01fe
shellMptrCmd: shellMptrCmd:
.db "mptr", 0b011, 0b001, 0 .db "mptr", 0b111, 0b001, 0
shellMptr: shellMptr:
push hl push hl
; do we have any arguments
ld a, b
or a ; cp 0
jp z, .print
; reminder: z80 is little-endian ; reminder: z80 is little-endian
ld a, (hl) ld a, (hl)
ld (SHELL_MEM_PTR+1), a ld (SHELL_MEM_PTR+1), a
@ -235,6 +240,7 @@ shellMptr:
ld a, (hl) ld a, (hl)
ld (SHELL_MEM_PTR), a ld (SHELL_MEM_PTR), a
.print:
ld hl, (SHELL_MEM_PTR) ld hl, (SHELL_MEM_PTR)
ld a, h ld a, h
call printHex call printHex