diff options
Diffstat (limited to 'newasm/whitespace.s')
-rw-r--r-- | newasm/whitespace.s | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/newasm/whitespace.s b/newasm/whitespace.s new file mode 100644 index 0000000..f4d8d9f --- /dev/null +++ b/newasm/whitespace.s @@ -0,0 +1,21 @@ +.syntax unified +.cpu cortex-m0plus +.thumb + +.type whitespace, %function +.global whitespace + +// 1 unexpected char + +whitespace: + LDRB R0, [R1] // get a char + CMP R0, ' // space + BEQ 1f + MOVS R0, #1 // return code 1 (unexpected char) + BX LR +1: ADDS R1, 1 // consume the character + LDRB R0, [R1] // get another character + CMP R0, ' // check if space + BEQ 1b // if so keep getting chars + MOVS R0, #0 // return code 0 (success) + BX LR |