diff options
Diffstat (limited to 'newasm/parsers')
| -rw-r--r-- | newasm/parsers/decimal.s | 4 | ||||
| -rw-r--r-- | newasm/parsers/immediate.s | 13 | ||||
| -rw-r--r-- | newasm/parsers/label.s | 5 | ||||
| -rw-r--r-- | newasm/parsers/register.s | 13 |
4 files changed, 22 insertions, 13 deletions
diff --git a/newasm/parsers/decimal.s b/newasm/parsers/decimal.s index a1516d2..cc9dff4 100644 --- a/newasm/parsers/decimal.s +++ b/newasm/parsers/decimal.s @@ -5,8 +5,6 @@ .type decimal, %function .global decimal -// 1 not a digit - // R4 input stream // R2 output value @@ -35,5 +33,5 @@ loop: LDRB R0, [R4] // get another char MULS R2, R3 // shift result by one decimal place ADDS R2, R0 // accumulate into R2 B loop // keep getting digits -bad: MOVS R0, #1 // return code 1 (not a digit) +bad: MOVS R0, #5 // return code 5 (not a digit) BX LR diff --git a/newasm/parsers/immediate.s b/newasm/parsers/immediate.s new file mode 100644 index 0000000..ac3e578 --- /dev/null +++ b/newasm/parsers/immediate.s @@ -0,0 +1,13 @@ +.syntax unified +.cpu cortex-m0plus +.thumb + +.type immediate, %function +.global immediate + +// R4 input buffer +// R2 output buffer + +immediate:PUSH {LR} + BL decimal + POP {PC} diff --git a/newasm/parsers/label.s b/newasm/parsers/label.s index 4770e6c..45d39e5 100644 --- a/newasm/parsers/label.s +++ b/newasm/parsers/label.s @@ -5,9 +5,6 @@ .type label, %function .global label -// 1 unexpected begin char -// 2 doesn't end with colon - // R4 input buffer // R2 output buffer @@ -23,7 +20,7 @@ label: PUSH {LR} LDRB R0, [R4] // get a char CMP R0, ': // colon BEQ 3f - MOVS R0, #2 // return code 2 (expected colon) + MOVS R0, #3 // return code 3 (expected colon) POP {PC} 3: ADDS R4, 1 // consume the colon MOVS R0, #0 // return code 0 (success) diff --git a/newasm/parsers/register.s b/newasm/parsers/register.s index 48ebf7a..9334aa3 100644 --- a/newasm/parsers/register.s +++ b/newasm/parsers/register.s @@ -5,9 +5,6 @@ .type register, %function .global register -// 1 unexpected char -// 2 invalid general-purpose register number - // R4 input buffer // R2 output buffer @@ -21,9 +18,12 @@ r_test: CMP R0, 'R POP {PC} // error code already in R0 validate: CMP R2, #12 // general purpose registers 0-12 BLS success - MOVS R0, #2 // invalid register number error code + MOVS R0, #7 // invalid register number error code POP {PC} -special: LDRH R0, [R4] // get two bytes from input stream +special: LDRB R0, [R4] // get two bytes from input stream + LDRB R1, [R4, 1] + LSLS R1, 8 + ORRS R0, R1 ADR R2, table // get address of table MOVS R3, 0 // set table offset to 0 loop: LDRH R1, [R2, R3] // get two bytes from table at current offset @@ -32,7 +32,7 @@ loop: LDRH R1, [R2, R3] // get two bytes from table at current offset ADDS R3, 2 // increment table offset CMP R3, 6 // compare offset to table size BLO loop // loop until end of table - MOVS R0, #1 // return code 1 (unexpected char) + MOVS R0, #6 // return code 6 (expected register) POP {PC} done: ADDS R4, 2 // consume two chars LSRS R3, 1 // divide table offset by two to row @@ -41,6 +41,7 @@ done: ADDS R4, 2 // consume two chars success: MOVS R0, #0 // return code 0 (success) POP {PC} + .align 4 table: .ascii "SP" .ascii "LR" .ascii "PC" |