+# See LICENSE for license details.
+
#include "encoding.h"
-#ifdef __riscv64
+#if __riscv_xlen == 64
# define LREG ld
# define SREG sd
+# define REGBYTES 8
#else
# define LREG lw
# define SREG sw
+# define REGBYTES 4
#endif
- .text
+ .section ".text.init"
.globl _start
-
_start:
li x1, 0
li x2, 0
li x30,0
li x31,0
- # initialize status, enable fp, accelerator, interrupts
- li a0, SR_S | SR_PEI | SR_EF | SR_EA
- csrw status, a0
+ # enable FPU and accelerator if present
+ li t0, MSTATUS_FS | MSTATUS_XS
+ csrs mstatus, t0
-#ifdef __riscv64
- li a0, SR_U64 | SR_S64
- csrs status, a0
+ # make sure XLEN agrees with compilation choice
+ li t0, 1
+ slli t0, t0, 31
+#if __riscv_xlen == 64
+ bgez t0, 1f
+#else
+ bltz t0, 1f
#endif
+2:
+ li a0, 1
+ sw a0, tohost, t0
+ j 2b
+1:
- csrr t0, status
- and t1, t0, SR_EA
- sw t1, have_vec, t2
-
- ## if that didn't stick, we don't have a FPU, so don't initialize it
- and t1, t0, SR_EF
- beqz t1, 1f
+#ifdef __riscv_flen
+ # initialize FPU if we have one
+ la t0, 1f
+ csrw mtvec, t0
fssr x0
fmv.s.x f0, x0
fmv.s.x f30,x0
fmv.s.x f31,x0
1:
+#endif
+ # initialize trap vector
la t0, trap_entry
- csrw evec, t0
+ csrw mtvec, t0
+
+ # initialize global pointer
+.option push
+.option norelax
+ la gp, __global_pointer$
+.option pop
la tp, _end + 63
and tp, tp, -64
- # get core id and number of cores
- csrr a0, hartid
- lw a1, 4(zero)
+ # get core id
+ csrr a0, mhartid
+ # for now, assume only 1 core
+ li a1, 1
+1:bgeu a0, a1, 1b
# give each core 128KB of stack + TLS
#define STKSHIFT 17
sll sp, sp, STKSHIFT
add sp, sp, tp
- # offset thread pointer by thread pointer bias
- lui t0, %tprel_hi(tls_start)
- add t0, t0, tp, %tprel_add(tls_start)
- add t0, t0, %tprel_lo(tls_start)
- sub t0, t0, tp
- sub tp, tp, t0
-
- la t0, _init
- csrw epc, t0
- sret
+ j _init
+ .align 2
trap_entry:
- csrw sup0, sp
- csrw sup1, t0
- csrr t0, status
- andi t0, t0, SR_PS
- bnez t0, 1f
- la sp, kstacktop
-1:
addi sp, sp, -272
- csrr t0, sup1
-
- SREG x1, 8(sp)
- SREG x2, 16(sp)
- SREG x3, 24(sp)
- SREG x4, 32(sp)
- SREG x5, 40(sp)
- SREG x6, 48(sp)
- SREG x7, 56(sp)
- SREG x8, 64(sp)
- SREG x9, 72(sp)
- SREG x10, 80(sp)
- SREG x11, 88(sp)
- SREG x12, 96(sp)
- SREG x13, 104(sp)
- SREG x14, 112(sp)
- SREG x15, 120(sp)
- SREG x16, 128(sp)
- SREG x17, 136(sp)
- SREG x18, 144(sp)
- SREG x19, 152(sp)
- SREG x20, 160(sp)
- SREG x21, 168(sp)
- SREG x22, 176(sp)
- SREG x23, 184(sp)
- SREG x24, 192(sp)
- SREG x25, 200(sp)
- SREG x26, 208(sp)
- SREG x27, 216(sp)
- SREG x28, 224(sp)
- SREG x29, 232(sp)
- SREG x30, 240(sp)
- SREG x31, 248(sp)
-
- csrr t0, sup0
- csrr t1, status
- SREG t0, 256(sp)
- SREG t1, 264(sp)
-
- csrr a0, cause
- csrr a1, epc
+
+ SREG x1, 1*REGBYTES(sp)
+ SREG x2, 2*REGBYTES(sp)
+ SREG x3, 3*REGBYTES(sp)
+ SREG x4, 4*REGBYTES(sp)
+ SREG x5, 5*REGBYTES(sp)
+ SREG x6, 6*REGBYTES(sp)
+ SREG x7, 7*REGBYTES(sp)
+ SREG x8, 8*REGBYTES(sp)
+ SREG x9, 9*REGBYTES(sp)
+ SREG x10, 10*REGBYTES(sp)
+ SREG x11, 11*REGBYTES(sp)
+ SREG x12, 12*REGBYTES(sp)
+ SREG x13, 13*REGBYTES(sp)
+ SREG x14, 14*REGBYTES(sp)
+ SREG x15, 15*REGBYTES(sp)
+ SREG x16, 16*REGBYTES(sp)
+ SREG x17, 17*REGBYTES(sp)
+ SREG x18, 18*REGBYTES(sp)
+ SREG x19, 19*REGBYTES(sp)
+ SREG x20, 20*REGBYTES(sp)
+ SREG x21, 21*REGBYTES(sp)
+ SREG x22, 22*REGBYTES(sp)
+ SREG x23, 23*REGBYTES(sp)
+ SREG x24, 24*REGBYTES(sp)
+ SREG x25, 25*REGBYTES(sp)
+ SREG x26, 26*REGBYTES(sp)
+ SREG x27, 27*REGBYTES(sp)
+ SREG x28, 28*REGBYTES(sp)
+ SREG x29, 29*REGBYTES(sp)
+ SREG x30, 30*REGBYTES(sp)
+ SREG x31, 31*REGBYTES(sp)
+
+ csrr a0, mcause
+ csrr a1, mepc
mv a2, sp
jal handle_trap
- csrw epc, a0
-
- LREG t0, 256(sp)
- LREG t1, 264(sp)
- csrw sup0, t0
- csrw status, t1
-
- LREG x1, 8(sp)
- LREG x2, 16(sp)
- LREG x3, 24(sp)
- LREG x4, 32(sp)
- LREG x5, 40(sp)
- LREG x6, 48(sp)
- LREG x7, 56(sp)
- LREG x8, 64(sp)
- LREG x9, 72(sp)
- LREG x10, 80(sp)
- LREG x11, 88(sp)
- LREG x12, 96(sp)
- LREG x13, 104(sp)
- LREG x14, 112(sp)
- LREG x15, 120(sp)
- LREG x16, 128(sp)
- LREG x17, 136(sp)
- LREG x18, 144(sp)
- LREG x19, 152(sp)
- LREG x20, 160(sp)
- LREG x21, 168(sp)
- LREG x22, 176(sp)
- LREG x23, 184(sp)
- LREG x24, 192(sp)
- LREG x25, 200(sp)
- LREG x26, 208(sp)
- LREG x27, 216(sp)
- LREG x28, 224(sp)
- LREG x29, 232(sp)
- LREG x30, 240(sp)
- LREG x31, 248(sp)
-
- csrr sp, sup0
- sret
-
-.bss
-.align 4
-.skip 4096
-kstacktop:
-
-.section .tbss
-tls_start:
+ csrw mepc, a0
+
+ # Remain in M-mode after eret
+ li t0, MSTATUS_MPP
+ csrs mstatus, t0
+
+ LREG x1, 1*REGBYTES(sp)
+ LREG x2, 2*REGBYTES(sp)
+ LREG x3, 3*REGBYTES(sp)
+ LREG x4, 4*REGBYTES(sp)
+ LREG x5, 5*REGBYTES(sp)
+ LREG x6, 6*REGBYTES(sp)
+ LREG x7, 7*REGBYTES(sp)
+ LREG x8, 8*REGBYTES(sp)
+ LREG x9, 9*REGBYTES(sp)
+ LREG x10, 10*REGBYTES(sp)
+ LREG x11, 11*REGBYTES(sp)
+ LREG x12, 12*REGBYTES(sp)
+ LREG x13, 13*REGBYTES(sp)
+ LREG x14, 14*REGBYTES(sp)
+ LREG x15, 15*REGBYTES(sp)
+ LREG x16, 16*REGBYTES(sp)
+ LREG x17, 17*REGBYTES(sp)
+ LREG x18, 18*REGBYTES(sp)
+ LREG x19, 19*REGBYTES(sp)
+ LREG x20, 20*REGBYTES(sp)
+ LREG x21, 21*REGBYTES(sp)
+ LREG x22, 22*REGBYTES(sp)
+ LREG x23, 23*REGBYTES(sp)
+ LREG x24, 24*REGBYTES(sp)
+ LREG x25, 25*REGBYTES(sp)
+ LREG x26, 26*REGBYTES(sp)
+ LREG x27, 27*REGBYTES(sp)
+ LREG x28, 28*REGBYTES(sp)
+ LREG x29, 29*REGBYTES(sp)
+ LREG x30, 30*REGBYTES(sp)
+ LREG x31, 31*REGBYTES(sp)
+
+ addi sp, sp, 272
+ mret
+
+.section ".tdata.begin"
+.globl _tdata_begin
+_tdata_begin:
+
+.section ".tdata.end"
+.globl _tdata_end
+_tdata_end:
+
+.section ".tbss.end"
+.globl _tbss_end
+_tbss_end:
+
+.section ".tohost","aw",@progbits
+.align 6
+.globl tohost
+tohost: .dword 0
+.align 6
+.globl fromhost
+fromhost: .dword 0
projects / riscv-tests.git / blobdiff