1 files changed, 27 insertions, 0 deletions
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