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| author | Yann Herklotz <git@yannherklotz.com> | 2022-11-24 22:27:15 +0000 |
|---|---|---|
| committer | Yann Herklotz <git@yannherklotz.com> | 2022-11-24 22:27:15 +0000 |
| commit | cfe60025ab06c73c44ce6b962a258668b3a90431 (patch) | |
| tree | 292d7b2b01a6e0f2ee31b9d133312723980235c1 /riscv/picorv32/scripts/romload/start.S | |
| parent | c0056cea555efe0d6775e3b28ffa5a4a91293097 (diff) | |
| download | butterstick-cfe60025ab06c73c44ce6b962a258668b3a90431.tar.gz butterstick-cfe60025ab06c73c44ce6b962a258668b3a90431.zip | |
Move all files
Diffstat (limited to 'riscv/picorv32/scripts/romload/start.S')
| -rw-r--r-- | riscv/picorv32/scripts/romload/start.S | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/riscv/picorv32/scripts/romload/start.S b/riscv/picorv32/scripts/romload/start.S new file mode 100644 index 0000000..be59808 --- /dev/null +++ b/riscv/picorv32/scripts/romload/start.S @@ -0,0 +1,52 @@ +.section .text +.global _start +.global _pvstart + +_pvstart: +/* zero-initialize all registers */ +addi x1, zero, 0 +addi x2, zero, 0 +addi x3, zero, 0 +addi x4, zero, 0 +addi x5, zero, 0 +addi x6, zero, 0 +addi x7, zero, 0 +addi x8, zero, 0 +addi x9, zero, 0 +addi x10, zero, 0 +addi x11, zero, 0 +addi x12, zero, 0 +addi x13, zero, 0 +addi x14, zero, 0 +addi x15, zero, 0 +addi x16, zero, 0 +addi x17, zero, 0 +addi x18, zero, 0 +addi x19, zero, 0 +addi x20, zero, 0 +addi x21, zero, 0 +addi x22, zero, 0 +addi x23, zero, 0 +addi x24, zero, 0 +addi x25, zero, 0 +addi x26, zero, 0 +addi x27, zero, 0 +addi x28, zero, 0 +addi x29, zero, 0 +addi x30, zero, 0 +addi x31, zero, 0 + +/* set stack pointer */ + +lui sp, %hi(4*1024*1024) +addi sp, sp, %lo(4*1024*1024) + +/* push zeros on the stack for argc and argv */ +/* (stack is aligned to 16 bytes in riscv calling convention) */ +addi sp,sp,-16 +sw zero,0(sp) +sw zero,4(sp) +sw zero,8(sp) +sw zero,12(sp) + +j _start |