diff options
Diffstat (limited to 'src/flash_button.s')
| -rw-r--r-- | src/flash_button.s | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/src/flash_button.s b/src/flash_button.s new file mode 100644 index 0000000..9b702e4 --- /dev/null +++ b/src/flash_button.s @@ -0,0 +1,68 @@ +/* + * flash_button.s + * + * Copyright © 2018 Thomas White <taw@bitwiz.org.uk> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +.include "swi_numbers.h" + +.global flash_button + +flash_button: + MOV R0, #0 @ Get GPLEV0 + SWI OS_GetGPIO + TST R0, #1<<17 @ Check GPIO 17 + BLNE flash_leds + B flash_button + +flash_leds: + STMDB R13!, {LR} + + MOV R2, #5 @ Number of times to flash + +1: + MOV R0, #0 @ Flash first set of GPIOs + + MOV R1, #1<<16 + SWI OS_ClearGPIO + MOV R1, #1<<18 + SWI OS_SetGPIO + + BL pause + + MOV R1, #1<<18 + SWI OS_ClearGPIO + MOV R1, #1<<16 + SWI OS_SetGPIO + + BL pause + + SUBS R2, R2, #1 + BNE 1b + + MOV R1, #1<<18 + ORR R1, #1<<16 + SWI OS_ClearGPIO + + LDMIA R13!, {PC} + +pause: + MOV R1, #0x3f000 +1: + SUBS R1, R1, #1 + BNE 1b + MOV PC, LR |