tinyriscv/sdk/bsp/trap_entry.S

110 lines
2.6 KiB
ArmAsm

#define REGBYTES 4
#define STORE sw
#define LOAD lw
.section .text.entry
.align 2
.global trap_entry
trap_entry:
addi sp, sp, -32*REGBYTES
STORE x1, 1*REGBYTES(sp)
STORE x2, 2*REGBYTES(sp)
STORE x3, 3*REGBYTES(sp)
STORE x4, 4*REGBYTES(sp)
STORE x5, 5*REGBYTES(sp)
STORE x6, 6*REGBYTES(sp)
STORE x7, 7*REGBYTES(sp)
STORE x8, 8*REGBYTES(sp)
STORE x9, 9*REGBYTES(sp)
STORE x10, 10*REGBYTES(sp)
STORE x11, 11*REGBYTES(sp)
STORE x12, 12*REGBYTES(sp)
STORE x13, 13*REGBYTES(sp)
STORE x14, 14*REGBYTES(sp)
STORE x15, 15*REGBYTES(sp)
STORE x16, 16*REGBYTES(sp)
STORE x17, 17*REGBYTES(sp)
STORE x18, 18*REGBYTES(sp)
STORE x19, 19*REGBYTES(sp)
STORE x20, 20*REGBYTES(sp)
STORE x21, 21*REGBYTES(sp)
STORE x22, 22*REGBYTES(sp)
STORE x23, 23*REGBYTES(sp)
STORE x24, 24*REGBYTES(sp)
STORE x25, 25*REGBYTES(sp)
#ifndef SIMULATION
STORE x26, 26*REGBYTES(sp)
STORE x27, 27*REGBYTES(sp)
#endif
STORE x28, 28*REGBYTES(sp)
STORE x29, 29*REGBYTES(sp)
STORE x30, 30*REGBYTES(sp)
STORE x31, 31*REGBYTES(sp)
csrr a0, mcause
csrr a1, mepc
test_if_asynchronous:
srli a2, a0, 31 /* MSB of mcause is 1 if handing an asynchronous interrupt - shift to LSB to clear other bits. */
beq a2, x0, handle_synchronous /* Branch past interrupt handing if not asynchronous. */
call interrupt_handler
j asynchronous_return
handle_synchronous:
call exception_handler
addi a1, a1, 4
csrw mepc, a1
asynchronous_return:
LOAD x1, 1*REGBYTES(sp)
LOAD x2, 2*REGBYTES(sp)
LOAD x3, 3*REGBYTES(sp)
LOAD x4, 4*REGBYTES(sp)
LOAD x5, 5*REGBYTES(sp)
LOAD x6, 6*REGBYTES(sp)
LOAD x7, 7*REGBYTES(sp)
LOAD x8, 8*REGBYTES(sp)
LOAD x9, 9*REGBYTES(sp)
LOAD x10, 10*REGBYTES(sp)
LOAD x11, 11*REGBYTES(sp)
LOAD x12, 12*REGBYTES(sp)
LOAD x13, 13*REGBYTES(sp)
LOAD x14, 14*REGBYTES(sp)
LOAD x15, 15*REGBYTES(sp)
LOAD x16, 16*REGBYTES(sp)
LOAD x17, 17*REGBYTES(sp)
LOAD x18, 18*REGBYTES(sp)
LOAD x19, 19*REGBYTES(sp)
LOAD x20, 20*REGBYTES(sp)
LOAD x21, 21*REGBYTES(sp)
LOAD x22, 22*REGBYTES(sp)
LOAD x23, 23*REGBYTES(sp)
LOAD x24, 24*REGBYTES(sp)
LOAD x25, 25*REGBYTES(sp)
#ifndef SIMULATION
LOAD x26, 26*REGBYTES(sp)
LOAD x27, 27*REGBYTES(sp)
#endif
LOAD x28, 28*REGBYTES(sp)
LOAD x29, 29*REGBYTES(sp)
LOAD x30, 30*REGBYTES(sp)
LOAD x31, 31*REGBYTES(sp)
addi sp, sp, 32*REGBYTES
mret
.weak interrupt_handler
interrupt_handler:
1:
j 1b
.weak exception_handler
exception_handler:
2:
j 2b