From 3fff6023602822531efdae30bc8ebf862967f1ef Mon Sep 17 00:00:00 2001
From: Friedrich Beckmann <friedrich.beckmann@hs-augsburg.de>
Date: Mon, 25 Jul 2022 17:55:39 +0200
Subject: Initial Commit

---
 VexRiscv/src/main/c/murax/xipBootloader/demo.S | 27 ++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 VexRiscv/src/main/c/murax/xipBootloader/demo.S

(limited to 'VexRiscv/src/main/c/murax/xipBootloader/demo.S')

diff --git a/VexRiscv/src/main/c/murax/xipBootloader/demo.S b/VexRiscv/src/main/c/murax/xipBootloader/demo.S
new file mode 100644
index 0000000..064db6f
--- /dev/null
+++ b/VexRiscv/src/main/c/murax/xipBootloader/demo.S
@@ -0,0 +1,27 @@
+#define GPIO_BASE 0xF0000000
+#define GPIO_OUTPUT 4
+#define GPIO_OUTPUT_ENABLE 8
+
+
+.global crtStart
+
+crtStart:
+
+  li x31, 0x12340000 // magic word expected by bootloader
+  
+  li x31, GPIO_BASE
+  li t0, 0x000000FF
+  sw t0, GPIO_OUTPUT_ENABLE(x31)
+
+  li t0,1
+redo:
+  sw t0, GPIO_OUTPUT(x31)
+  li t1,10000
+  slli t0,t0,1
+  andi t0,t0,0xFF
+  bnez t0, loop
+  li t0,1
+loop:
+  addi t1,t1,-1
+  bnez t1, loop
+  j redo
-- 
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