rvc/bare_metal_test/init.S

137 lines
3.2 KiB
ArmAsm

#define SLL32 sll
#define STORE sw
#define LOAD lw
#define LWU lw
#define LOG_REGBYTES 2
#define REGBYTES (1 << LOG_REGBYTES)
.section .entry, "ax", %progbits
.align 4
.globl _start
_start:
csrw mie, zero
csrw mip, zero
lla a3, _start_hang
csrw mtvec, a3
lla a3, _s_trap_entry
csrw stvec, a3
# enable supervisor software interrupt
li a3, 0x2
csrw sie, a3
csrw mie, a3
csrw mideleg, a3
li a3, 0x00b
csrs mstatus, a3
lla sp, _estack
lla a3, main
csrw mepc, a3
li a3, 0x800
csrs mstatus, a3
mret
j _start_hang
.section .entry, "ax", %progbits
.align 4
.globl _start_hang
_start_hang:
j _start_hang
.section .entry, "ax", %progbits
.align 4
.globl _trap_entry
_s_trap_entry:
addi sp,sp,-320
# save gprs
STORE x1,1*REGBYTES(x2)
STORE x3,3*REGBYTES(x2)
STORE x4,4*REGBYTES(x2)
STORE x5,5*REGBYTES(x2)
STORE x6,6*REGBYTES(x2)
STORE x7,7*REGBYTES(x2)
STORE x8,8*REGBYTES(x2)
STORE x9,9*REGBYTES(x2)
STORE x10,10*REGBYTES(x2)
STORE x11,11*REGBYTES(x2)
STORE x12,12*REGBYTES(x2)
STORE x13,13*REGBYTES(x2)
STORE x14,14*REGBYTES(x2)
STORE x15,15*REGBYTES(x2)
STORE x16,16*REGBYTES(x2)
STORE x17,17*REGBYTES(x2)
STORE x18,18*REGBYTES(x2)
STORE x19,19*REGBYTES(x2)
STORE x20,20*REGBYTES(x2)
STORE x21,21*REGBYTES(x2)
STORE x22,22*REGBYTES(x2)
STORE x23,23*REGBYTES(x2)
STORE x24,24*REGBYTES(x2)
STORE x25,25*REGBYTES(x2)
STORE x26,26*REGBYTES(x2)
STORE x27,27*REGBYTES(x2)
STORE x28,28*REGBYTES(x2)
STORE x29,29*REGBYTES(x2)
STORE x30,30*REGBYTES(x2)
STORE x31,31*REGBYTES(x2)
# get sr, epc, badvaddr, cause
csrr s0, sstatus
csrr t1, sepc
csrr t2, stval
csrr t3, scause
STORE t0, 2*REGBYTES(x2)
STORE s0, 32*REGBYTES(x2)
STORE t1, 33*REGBYTES(x2)
STORE t2, 34*REGBYTES(x2)
STORE t3, 35*REGBYTES(x2)
mv a0, sp
jal handle_trap
mv a0, sp
addi sp, sp, 320
LOAD t0, 32*REGBYTES(a0)
LOAD t1, 33*REGBYTES(a0)
csrw sstatus, t0
csrw sepc, t1
# restore x registers
LOAD x1,1*REGBYTES(a0)
LOAD x3,3*REGBYTES(a0)
LOAD x4,4*REGBYTES(a0)
LOAD x5,5*REGBYTES(a0)
LOAD x6,6*REGBYTES(a0)
LOAD x7,7*REGBYTES(a0)
LOAD x8,8*REGBYTES(a0)
LOAD x9,9*REGBYTES(a0)
LOAD x11,11*REGBYTES(a0)
LOAD x12,12*REGBYTES(a0)
LOAD x13,13*REGBYTES(a0)
LOAD x14,14*REGBYTES(a0)
LOAD x15,15*REGBYTES(a0)
LOAD x16,16*REGBYTES(a0)
LOAD x17,17*REGBYTES(a0)
LOAD x18,18*REGBYTES(a0)
LOAD x19,19*REGBYTES(a0)
LOAD x20,20*REGBYTES(a0)
LOAD x21,21*REGBYTES(a0)
LOAD x22,22*REGBYTES(a0)
LOAD x23,23*REGBYTES(a0)
LOAD x24,24*REGBYTES(a0)
LOAD x25,25*REGBYTES(a0)
LOAD x26,26*REGBYTES(a0)
LOAD x27,27*REGBYTES(a0)
LOAD x28,28*REGBYTES(a0)
LOAD x29,29*REGBYTES(a0)
LOAD x30,30*REGBYTES(a0)
LOAD x31,31*REGBYTES(a0)
# restore a0 last
LOAD x10,10*REGBYTES(a0)
# gtfo
sret