1 files changed, 103 insertions, 0 deletions
diff --git a/misc/blink.s b/misc/blink.s
new file mode 100644
index 0000000..46e6eff
--- /dev/null
+++ b/misc/blink.s
@@ -0,0 +1,103 @@
+.syntax unified
+.cpu cortex-m0plus
+.thumb
+
+.equ IO_BANK0_BASE,   0x40014000
+.equ GPIO25_STATUS,   (IO_BANK0_BASE + 0x0c8)
+.equ GPIO25_CTRL,     (IO_BANK0_BASE + 0x0cc)
+
+.equ SIO_BASE,          0xd0000000
+.equ GPIO_OUT_SET_OFST, 0x014
+.equ GPIO_OUT_XOR_OFST, 0x01c
+.equ GPIO_OE_SET_OFST,  0x024
+
+.equ ATOMIC_CLEAR,    0x3000
+
+.type setup_led, %function
+.global setup_led
+
+setup_led:
+  ldr r1, =GPIO25_CTRL
+  movs r0, 5 // SIO function = 5
+  str r0, [r1, 0]
+  ldr r1, =SIO_BASE
+  movs r0, 1
+  lsls r0, 25 // GPIO 25 (LED) output enable
+  str r0, [r1, GPIO_OE_SET_OFST]
+  bx lr
+
+.type led_on, %function
+.global led_on
+
+led_on:
+  ldr r1, =SIO_BASE
+  movs r0, 1
+  lsls r0, 25
+  str r0, [r1, GPIO_OUT_SET_OFST]
+1:
+  b 1b
+
+.type blink, %function
+.global blink
+
+blink:
+  ldr r1, =SIO_BASE
+  movs r0, 1
+  lsls r0, 25
+1:
+  str r0, [r1, GPIO_OUT_XOR_OFST]
+  bl delay_1s
+  b 1b
+
+.type long_blink, %function
+.global long_blink
+
+long_blink:
+  push {lr}
+  ldr r1, =SIO_BASE
+  movs r0, 1
+  lsls r0, 25
+  bl delay_1s
+  str r0, [r1, GPIO_OUT_XOR_OFST]
+  bl delay_1s
+  str r0, [r1, GPIO_OUT_XOR_OFST]
+  bl delay_1s
+  pop {pc}
+
+.type blinkN, %function
+.global blinkN
+
+blinkN:
+  push {lr}
+  ldr r1, =SIO_BASE
+  movs r2, 1
+  lsls r2, 25
+  tst r0, r0
+  beq done
+on_then_off:
+  str r2, [r1, GPIO_OUT_XOR_OFST]
+  bl delay_quick
+  str r2, [r1, GPIO_OUT_XOR_OFST]
+  bl delay_quick
+  subs r0, 1
+  bne on_then_off
+done:
+  pop {pc}
+
+.type blink_hex, %function
+.global blink_hex
+
+blink_hex:
+  push {lr}
+  movs r4, r0
+  movs r5, 0xf
+1:
+  ands r0, r5
+  bl blinkN
+  lsrs r4, 4
+  beq 2f
+  bl long_blink
+  movs r0, r4
+  b 1b
+2:
+  pop {pc}