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| author | Friedrich Beckmann <friedrich.beckmann@hs-augsburg.de> | 2022-07-25 17:55:39 +0200 |
|---|---|---|
| committer | Friedrich Beckmann <friedrich.beckmann@hs-augsburg.de> | 2022-07-25 17:55:39 +0200 |
| commit | 3fff6023602822531efdae30bc8ebf862967f1ef (patch) | |
| tree | 16028102b8d850f8ab3115d28a8539ca6bc5f51d /VexRiscv/src/main/c/murax/xipBootloader/demo.S | |
Initial Commit
Diffstat (limited to 'VexRiscv/src/main/c/murax/xipBootloader/demo.S')
| -rw-r--r-- | VexRiscv/src/main/c/murax/xipBootloader/demo.S | 27 |
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 |