picorv32/scripts/romload/start.S

53 lines
920 B
ArmAsm

.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