picorv32/firmware/start.S

538 lines
9.3 KiB
ArmAsm

// This is free and unencumbered software released into the public domain.
//
// Anyone is free to copy, modify, publish, use, compile, sell, or
// distribute this software, either in source code form or as a compiled
// binary, for any purpose, commercial or non-commercial, and by any
// means.
#define ENABLE_QREGS
#define ENABLE_HELLO
#define ENABLE_RVTST
#define ENABLE_SIEVE
#define ENABLE_MULTST
#define ENABLE_STATS
#ifndef ENABLE_QREGS
# undef ENABLE_RVTST
#endif
// Only save registers in IRQ wrapper that are to be saved by the caller in
// the RISC-V ABI, with the excpetion of the stack pointer. The IRQ handler
// will save the rest if necessary. I.e. skip x3, x4, x8, x9, and x18-x27.
#undef ENABLE_FASTIRQ
#include "custom_ops.S"
.section .text
.global irq
.global hello
.global sieve
.global multest
.global hard_mul
.global hard_mulh
.global hard_mulhsu
.global hard_mulhu
.global hard_div
.global hard_divu
.global hard_rem
.global hard_remu
.global stats
reset_vec:
// no more than 16 bytes here !
picorv32_waitirq_insn(zero)
picorv32_maskirq_insn(zero, zero)
j start
/* Interrupt handler
**********************************/
.balign 16
irq_vec:
/* save registers */
#ifdef ENABLE_QREGS
picorv32_setq_insn(q2, x1)
picorv32_setq_insn(q3, x2)
lui x1, %hi(irq_regs)
addi x1, x1, %lo(irq_regs)
picorv32_getq_insn(x2, q0)
sw x2, 0*4(x1)
picorv32_getq_insn(x2, q2)
sw x2, 1*4(x1)
picorv32_getq_insn(x2, q3)
sw x2, 2*4(x1)
#ifdef ENABLE_FASTIRQ
sw x5, 5*4(x1)
sw x6, 6*4(x1)
sw x7, 7*4(x1)
sw x10, 10*4(x1)
sw x11, 11*4(x1)
sw x12, 12*4(x1)
sw x13, 13*4(x1)
sw x14, 14*4(x1)
sw x15, 15*4(x1)
sw x16, 16*4(x1)
sw x17, 17*4(x1)
sw x28, 28*4(x1)
sw x29, 29*4(x1)
sw x30, 30*4(x1)
sw x31, 31*4(x1)
#else
sw x3, 3*4(x1)
sw x4, 4*4(x1)
sw x5, 5*4(x1)
sw x6, 6*4(x1)
sw x7, 7*4(x1)
sw x8, 8*4(x1)
sw x9, 9*4(x1)
sw x10, 10*4(x1)
sw x11, 11*4(x1)
sw x12, 12*4(x1)
sw x13, 13*4(x1)
sw x14, 14*4(x1)
sw x15, 15*4(x1)
sw x16, 16*4(x1)
sw x17, 17*4(x1)
sw x18, 18*4(x1)
sw x19, 19*4(x1)
sw x20, 20*4(x1)
sw x21, 21*4(x1)
sw x22, 22*4(x1)
sw x23, 23*4(x1)
sw x24, 24*4(x1)
sw x25, 25*4(x1)
sw x26, 26*4(x1)
sw x27, 27*4(x1)
sw x28, 28*4(x1)
sw x29, 29*4(x1)
sw x30, 30*4(x1)
sw x31, 31*4(x1)
#endif
#else // ENABLE_QREGS
#ifdef ENABLE_FASTIRQ
sw gp, 0*4+0x200(zero)
sw x1, 1*4+0x200(zero)
sw x2, 2*4+0x200(zero)
sw x5, 5*4+0x200(zero)
sw x6, 6*4+0x200(zero)
sw x7, 7*4+0x200(zero)
sw x10, 10*4+0x200(zero)
sw x11, 11*4+0x200(zero)
sw x12, 12*4+0x200(zero)
sw x13, 13*4+0x200(zero)
sw x14, 14*4+0x200(zero)
sw x15, 15*4+0x200(zero)
sw x16, 16*4+0x200(zero)
sw x17, 17*4+0x200(zero)
sw x28, 28*4+0x200(zero)
sw x29, 29*4+0x200(zero)
sw x30, 30*4+0x200(zero)
sw x31, 31*4+0x200(zero)
#else
sw gp, 0*4+0x200(zero)
sw x1, 1*4+0x200(zero)
sw x2, 2*4+0x200(zero)
sw x3, 3*4+0x200(zero)
sw x4, 4*4+0x200(zero)
sw x5, 5*4+0x200(zero)
sw x6, 6*4+0x200(zero)
sw x7, 7*4+0x200(zero)
sw x8, 8*4+0x200(zero)
sw x9, 9*4+0x200(zero)
sw x10, 10*4+0x200(zero)
sw x11, 11*4+0x200(zero)
sw x12, 12*4+0x200(zero)
sw x13, 13*4+0x200(zero)
sw x14, 14*4+0x200(zero)
sw x15, 15*4+0x200(zero)
sw x16, 16*4+0x200(zero)
sw x17, 17*4+0x200(zero)
sw x18, 18*4+0x200(zero)
sw x19, 19*4+0x200(zero)
sw x20, 20*4+0x200(zero)
sw x21, 21*4+0x200(zero)
sw x22, 22*4+0x200(zero)
sw x23, 23*4+0x200(zero)
sw x24, 24*4+0x200(zero)
sw x25, 25*4+0x200(zero)
sw x26, 26*4+0x200(zero)
sw x27, 27*4+0x200(zero)
sw x28, 28*4+0x200(zero)
sw x29, 29*4+0x200(zero)
sw x30, 30*4+0x200(zero)
sw x31, 31*4+0x200(zero)
#endif
#endif // ENABLE_QREGS
/* call interrupt handler C function */
lui sp, %hi(irq_stack)
addi sp, sp, %lo(irq_stack)
// arg0 = address of regs
lui a0, %hi(irq_regs)
addi a0, a0, %lo(irq_regs)
// arg1 = interrupt type
#ifdef ENABLE_QREGS
picorv32_getq_insn(a1, q1)
#else
addi a1, tp, 0
#endif
// call to C function
jal ra, irq
/* restore registers */
#ifdef ENABLE_QREGS
// new irq_regs address returned from C code in a0
addi x1, a0, 0
lw x2, 0*4(x1)
picorv32_setq_insn(q0, x2)
lw x2, 1*4(x1)
picorv32_setq_insn(q1, x2)
lw x2, 2*4(x1)
picorv32_setq_insn(q2, x2)
#ifdef ENABLE_FASTIRQ
lw x5, 5*4(x1)
lw x6, 6*4(x1)
lw x7, 7*4(x1)
lw x10, 10*4(x1)
lw x11, 11*4(x1)
lw x12, 12*4(x1)
lw x13, 13*4(x1)
lw x14, 14*4(x1)
lw x15, 15*4(x1)
lw x16, 16*4(x1)
lw x17, 17*4(x1)
lw x28, 28*4(x1)
lw x29, 29*4(x1)
lw x30, 30*4(x1)
lw x31, 31*4(x1)
#else
lw x3, 3*4(x1)
lw x4, 4*4(x1)
lw x5, 5*4(x1)
lw x6, 6*4(x1)
lw x7, 7*4(x1)
lw x8, 8*4(x1)
lw x9, 9*4(x1)
lw x10, 10*4(x1)
lw x11, 11*4(x1)
lw x12, 12*4(x1)
lw x13, 13*4(x1)
lw x14, 14*4(x1)
lw x15, 15*4(x1)
lw x16, 16*4(x1)
lw x17, 17*4(x1)
lw x18, 18*4(x1)
lw x19, 19*4(x1)
lw x20, 20*4(x1)
lw x21, 21*4(x1)
lw x22, 22*4(x1)
lw x23, 23*4(x1)
lw x24, 24*4(x1)
lw x25, 25*4(x1)
lw x26, 26*4(x1)
lw x27, 27*4(x1)
lw x28, 28*4(x1)
lw x29, 29*4(x1)
lw x30, 30*4(x1)
lw x31, 31*4(x1)
#endif
picorv32_getq_insn(x1, q1)
picorv32_getq_insn(x2, q2)
#else // ENABLE_QREGS
// new irq_regs address returned from C code in a0
addi a1, zero, 0x200
beq a0, a1, 1f
ebreak
1:
#ifdef ENABLE_FASTIRQ
lw gp, 0*4+0x200(zero)
lw x1, 1*4+0x200(zero)
lw x2, 2*4+0x200(zero)
lw x5, 5*4+0x200(zero)
lw x6, 6*4+0x200(zero)
lw x7, 7*4+0x200(zero)
lw x10, 10*4+0x200(zero)
lw x11, 11*4+0x200(zero)
lw x12, 12*4+0x200(zero)
lw x13, 13*4+0x200(zero)
lw x14, 14*4+0x200(zero)
lw x15, 15*4+0x200(zero)
lw x16, 16*4+0x200(zero)
lw x17, 17*4+0x200(zero)
lw x28, 28*4+0x200(zero)
lw x29, 29*4+0x200(zero)
lw x30, 30*4+0x200(zero)
lw x31, 31*4+0x200(zero)
#else
lw gp, 0*4+0x200(zero)
lw x1, 1*4+0x200(zero)
lw x2, 2*4+0x200(zero)
// do not restore x3 (gp)
lw x4, 4*4+0x200(zero)
lw x5, 5*4+0x200(zero)
lw x6, 6*4+0x200(zero)
lw x7, 7*4+0x200(zero)
lw x8, 8*4+0x200(zero)
lw x9, 9*4+0x200(zero)
lw x10, 10*4+0x200(zero)
lw x11, 11*4+0x200(zero)
lw x12, 12*4+0x200(zero)
lw x13, 13*4+0x200(zero)
lw x14, 14*4+0x200(zero)
lw x15, 15*4+0x200(zero)
lw x16, 16*4+0x200(zero)
lw x17, 17*4+0x200(zero)
lw x18, 18*4+0x200(zero)
lw x19, 19*4+0x200(zero)
lw x20, 20*4+0x200(zero)
lw x21, 21*4+0x200(zero)
lw x22, 22*4+0x200(zero)
lw x23, 23*4+0x200(zero)
lw x24, 24*4+0x200(zero)
lw x25, 25*4+0x200(zero)
lw x26, 26*4+0x200(zero)
lw x27, 27*4+0x200(zero)
lw x28, 28*4+0x200(zero)
lw x29, 29*4+0x200(zero)
lw x30, 30*4+0x200(zero)
lw x31, 31*4+0x200(zero)
#endif
#endif // ENABLE_QREGS
picorv32_retirq_insn()
#ifndef ENABLE_QREGS
.balign 0x200
#endif
irq_regs:
// registers are saved to this memory region during interrupt handling
// the program counter is saved as register 0
.fill 32,4
// stack for the interrupt handler
.fill 128,4
irq_stack:
/* Main program
**********************************/
start:
/* 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
#ifdef ENABLE_HELLO
/* set stack pointer */
lui sp,(128*1024)>>12
/* call hello C code */
jal ra,hello
#endif
/* running tests from riscv-tests */
#ifdef ENABLE_RVTST
# define TEST(n) \
.global n; \
addi x1, zero, 1000; \
picorv32_timer_insn(zero, x1); \
jal zero,n; \
.global n ## _ret; \
n ## _ret:
#else
# define TEST(n) \
.global n ## _ret; \
n ## _ret:
#endif
TEST(lui)
TEST(auipc)
TEST(j)
TEST(jal)
TEST(jalr)
TEST(beq)
TEST(bne)
TEST(blt)
TEST(bge)
TEST(bltu)
TEST(bgeu)
TEST(lb)
TEST(lh)
TEST(lw)
TEST(lbu)
TEST(lhu)
TEST(sb)
TEST(sh)
TEST(sw)
TEST(addi)
TEST(slti) // also tests sltiu
TEST(xori)
TEST(ori)
TEST(andi)
TEST(slli)
TEST(srli)
TEST(srai)
TEST(add)
TEST(sub)
TEST(sll)
TEST(slt) // what is with sltu ?
TEST(xor)
TEST(srl)
TEST(sra)
TEST(or)
TEST(and)
TEST(mulh)
TEST(mulhsu)
TEST(mulhu)
TEST(mul)
TEST(div)
TEST(divu)
TEST(rem)
TEST(remu)
TEST(simple)
/* set stack pointer */
lui sp,(128*1024)>>12
/* set gp and tp */
lui gp, %hi(0xdeadbeef)
addi gp, gp, %lo(0xdeadbeef)
addi tp, gp, 0
#ifdef ENABLE_SIEVE
/* call sieve C code */
jal ra,sieve
#endif
#ifdef ENABLE_MULTST
/* call multest C code */
jal ra,multest
#endif
#ifdef ENABLE_STATS
/* call stats C code */
jal ra,stats
#endif
/* print "DONE\n" */
lui a0,0x10000000>>12
addi a1,zero,'D'
addi a2,zero,'O'
addi a3,zero,'N'
addi a4,zero,'E'
addi a5,zero,'\n'
sw a1,0(a0)
sw a2,0(a0)
sw a3,0(a0)
sw a4,0(a0)
sw a5,0(a0)
li a0, 0x20000000
li a1, 123456789
sw a1,0(a0)
/* trap */
ebreak
/* Hard mul functions for multest.c
**********************************/
hard_mul:
mul a0, a0, a1
ret
hard_mulh:
mulh a0, a0, a1
ret
hard_mulhsu:
mulhsu a0, a0, a1
ret
hard_mulhu:
mulhu a0, a0, a1
ret
hard_div:
div a0, a0, a1
ret
hard_divu:
divu a0, a0, a1
ret
hard_rem:
rem a0, a0, a1
ret
hard_remu:
remu a0, a0, a1
ret