diff options
| -rw-r--r-- | newasm/Makefile | 39 | ||||
| -rw-r--r-- | newasm/data.s | 15 | ||||
| -rw-r--r-- | newasm/input.s | 84 | ||||
| -rw-r--r-- | newasm/main.s | 34 | ||||
| -rw-r--r-- | newasm/pico_bin.ld | 13 | ||||
| -rw-r--r-- | newasm/slowcat.c | 11 | ||||
| -rw-r--r-- | newasm/string.s | 32 | ||||
| -rw-r--r-- | newasm/uart.s | 44 |
8 files changed, 272 insertions, 0 deletions
diff --git a/newasm/Makefile b/newasm/Makefile new file mode 100644 index 0000000..3302630 --- /dev/null +++ b/newasm/Makefile @@ -0,0 +1,39 @@ +PICO = /dev/disk/by-label/RPI-RP2 +DEVICE = /dev/ttyUSB0 + +.PHONY: build +build: parse.he + +parse.he: parse.bin + od -An -tx2 -v parse.bin | sed "s/^ //" | tr " " "\n" | tr [:lower:] [:upper:] | sed "s/^/0x/" > parse.he + +parse.bin: parse.elf + arm-none-eabi-objcopy -O binary parse.elf parse.bin + +objects = main.o uart.o data.o string.o input.o + +parse.elf: pico_bin.ld $(objects) + arm-none-eabi-ld -T pico_bin.ld -o parse.elf $(objects) + +$(objects): %.o: %.s + arm-none-eabi-as -o $@ $< + +.PHONY: clean +clean: + rm -f parse.elf parse.bin parse.he slowcat $(objects) + +.PHONY: dump +dump: parse.bin + @od -Ax -tx2 -v parse.bin + +.PHONY: serial +serial: $(DEVICE) parse.he slowcat + cat parse.he | tr "\n" "\r" | ./slowcat | picocom -b 115200 -q $(DEVICE) + @echo + echo -n "G" | picocom -b 115200 -q $(DEVICE) + @echo + +$(DEVICE): + @echo Serial device not found + @echo Connect USB cable from USB-UART bridge + @false diff --git a/newasm/data.s b/newasm/data.s new file mode 100644 index 0000000..69d03ac --- /dev/null +++ b/newasm/data.s @@ -0,0 +1,15 @@ +.syntax unified +.cpu cortex-m0plus +.thumb + +.global crlf, word, hword, byte, align, asciz, SP, LR, PC + +crlf: .asciz "\r\n" +word: .asciz "word" +hword: .asciz "hword" +byte: .asciz "byte" +align: .asciz "align" +asciz: .asciz "asciz" +SP: .asciz "SP" +LR: .asciz "LR" +PC: .asciz "PC" diff --git a/newasm/input.s b/newasm/input.s new file mode 100644 index 0000000..d9c8c73 --- /dev/null +++ b/newasm/input.s @@ -0,0 +1,84 @@ +.syntax unified +.cpu cortex-m0plus +.thumb + +.type getline, %function +.global getline + +getline: + PUSH {R4, R5, LR} // save registers + MOVS R4, R0 // put strbuf in R4 +next: BL uart_recv // get a char + CMP R0, 0x03 // end of text (^C) + BEQ cancel // don't submit, start on next line + CMP R0, 0x04 // end of transmission (^D) + BEQ done // begin of line done, in a line submit the line + CMP R0, 0x7F // delete (backspace) + BEQ back // in a line go back a space, begin of line do nothing + CMP R0, 0x0D // carriage return (Enter) + BEQ submit // submit the line + CMP R0, 0x15 // NAK (^U) + BEQ retry // restart the line + // CMP R0, 0x1B // Escape (ESC) + // BEQ address // enter a new address to edit at + CMP R0, 0x20 // start of printable range + BLO next + CMP R0, 0x7E // end of printable range + BHI next +good: BL uart_send // echo the printable char + STRB R0, [R4, R5] // write the printable char + ADDS R5, 1 // increment strbuf offset + B next // get another char +cancel: MOVS R5, 0 // reset offset + STRB R5, [R4, R5] // write empty string + LDR R0, =crlf // newline + BL putstr + MOVS R0, 1 // error code 1 (line canceled) + POP {R4, R5, PC} // return +done: TST R5, R5 // check if offset is zero + BNE submit // if not zero submit line + STRB R5, [R4, R5] // clear input buffer + LDR R0, =crlf // newline + BL putstr + MOVS R0, 2 // error code 2 (end of input) + POP {R4, R5, PC} // return +back: TST R5, R5 // check if offset is zero + BEQ next // if so get another char + SUBS R5, 1 // push back offset + MOVS R0, 0 // null byte + STRB R0, [R4, R5] // delete character + MOVS R0, 0x08 // backspace + BL uart_send // move cursor back + MOVS R0, ' // space + BL uart_send // overwrite + MOVS R0, 0x08 // backspace + BL uart_send // move cursor back again + B next // get another char +submit: MOVS R0, 0 // null byte + STRB R0, [R4, R5] // terminate string + MOVS R0, 0x0D // carriage return + BL uart_send + MOVS R0, 0x0A // line feed + BL uart_send + MOVS R0, 0 // return code 0 (success) + POP {R4, R5, PC} +retry: MOVS R0, 0x08 // backspace + MOVS R1, ' // space + MOVS R2, R5 // repeat once per character + MOVS R5, 0 // reset offset + TST R2, R2 // check if already zero +1: BEQ 2f // while not zero + STRB R0, [R4, R5] // write backspace + ADDS R5, 1 + STRB R1, [R4, R5] // write space + ADDS R5, 1 + STRB R0, [R4, R5] // write backspace + ADDS R5, 1 + SUBS R2, 1 // decrement amount + B 1b // repeat +2: STRB R2, [R4, R5] // terminate string + MOVS R0, R4 // copy strbuf address + BL putstr // print backspace sequence + MOVS R5, 0 // null byte and reset offset + STRB R5, [R4] // write empty string + B next // get new chars diff --git a/newasm/main.s b/newasm/main.s new file mode 100644 index 0000000..7f3c038 --- /dev/null +++ b/newasm/main.s @@ -0,0 +1,34 @@ +.syntax unified +.cpu cortex-m0plus +.thumb + +.type main, %function +.global main, strbuf + +main: LDR R6, =0x20002000 + BL uart_recv +loop: BL prompt + LDR R0, strbuf + BL getline + LDR R0, strbuf + BL putstr + LDR R0, =crlf + BL putstr + B loop + BL uart_recv + LDR R0, =0x20000001 + BX R0 + + .align 4 +strbuf: .word 0x20001F00 + +prompt: PUSH {LR} + MOVS R0, R6 + BL send_hex + MOVS R0, ' + BL uart_send + LDR R0, [R6] + BL send_hex + MOVS R0, ' + BL uart_send + POP {PC} diff --git a/newasm/pico_bin.ld b/newasm/pico_bin.ld new file mode 100644 index 0000000..258ba57 --- /dev/null +++ b/newasm/pico_bin.ld @@ -0,0 +1,13 @@ +ENTRY(main) + +MEMORY { + FLASH(rx) : ORIGIN = 0x10000000, LENGTH = 2M + SRAM(rwx) : ORIGIN = 0x20001000, LENGTH = 264K +} + +SECTIONS { + .text : { + *(.text); + . = ALIGN(4); + } > SRAM +} diff --git a/newasm/slowcat.c b/newasm/slowcat.c new file mode 100644 index 0000000..e33f92a --- /dev/null +++ b/newasm/slowcat.c @@ -0,0 +1,11 @@ +#include <unistd.h> +#include <stdint.h> + +int main() { + uint8_t byte; + while (read(STDIN_FILENO, &byte, 1)) { + write(STDOUT_FILENO, &byte, 1); + usleep(5000); + } + return 0; +} diff --git a/newasm/string.s b/newasm/string.s new file mode 100644 index 0000000..c1dad1c --- /dev/null +++ b/newasm/string.s @@ -0,0 +1,32 @@ +.syntax unified +.cpu cortex-m0plus +.thumb + +.type putstr, %function +.type cmpstr, %function + +.global putstr, cmpstr + +putstr: LDR R3, =0x40034000 + MOVS R2, 0x20 +1: LDR R1, [R3, 0x18] + TST R1, R2 + BNE 1b + LDRB R1, [R0] + TST R1, R1 + BEQ 2f + STRB R1, [R3] + ADDS R0, 1 + B 1b +2: BX LR + +cmpstr: MOVS R4, 0 +1: LDRB R2, [R0, R4] + LDRB R3, [R1, R4] + CMP R2, R3 + BNE 2f + CMP R2, 0 + BEQ 2f + ADDS R4, 1 + B 1b +2: BX LR diff --git a/newasm/uart.s b/newasm/uart.s new file mode 100644 index 0000000..c4abb8a --- /dev/null +++ b/newasm/uart.s @@ -0,0 +1,44 @@ +.syntax unified +.cpu cortex-m0plus +.thumb + +.type uart_send, %function +.type uart_recv, %function +.type send_hex, %function + +.global uart_send +.global uart_recv +.global send_hex + +uart_send: LDR R1, =0x40034000 + MOVS R3, 0x20 +1: LDR R2, [R1, 0x18] + TST R2, R3 + BNE 1b + STRB R0, [R1] + BX LR + +uart_recv: LDR R1, =0x40034000 + MOVS R3, 0x10 +1: LDR R2, [R1, 0x18] + TST R2, R3 + BNE 1b + LDRB R0, [R1] + BX LR + +send_hex: PUSH {R4, R5, LR} + MOVS R4, R0 + MOVS R5, 8 +0: MOVS R0, 0x1C + RORS R4, R0 + MOVS R0, 0x0F + ANDS R0, R4 + CMP R0, 0x9 + BHI 1f + ADDS R0, 0x30 + B 2f +1: ADDS R0, 0x37 +2: BL uart_send + SUBS R5, 1 + BNE 0b + POP {R4, R5, PC} |