From f5e284223d25ee5beab98de95cd74e3ac72a39a6 Mon Sep 17 00:00:00 2001
From: Silvan Jegen <s.jegen@gmail.com>
Date: Mon, 22 Jul 2019 23:04:17 +0200
Subject: Implement first superblink version

---
 software/first/setup_gpio.S | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 software/first/setup_gpio.S

(limited to 'software/first/setup_gpio.S')

diff --git a/software/first/setup_gpio.S b/software/first/setup_gpio.S
new file mode 100644
index 0000000..39003b4
--- /dev/null
+++ b/software/first/setup_gpio.S
@@ -0,0 +1,19 @@
+.section .text
+.align 2
+.global setup_GPIO
+.include "memory_map.inc"
+.include "gpio.inc"
+
+setup_GPIO:
+	addi sp, sp, -16 # Allocate stack frame
+	sw ra, 12(sp)    # save return address to the stack
+
+	li t0, GPIO_CTRL_ADDR      # load base GPIO address 
+	li t1, GPIO_RGB_PINS       # get RGB offsets
+	sw t1, GPIO_OUTPUT_EN(t0)  # enable output on the RGB pins
+	sw t1, GPIO_OUTPUT_XOR(t0) # set the RGB pins to active high
+	sw x0, GPIO_OUTPUT_VAL(t0) # set all pins to 0
+
+  lw ra, 12(sp)   # load return address
+  addi sp, sp, 16 # deallocate stack frame
+	ret
-- 
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