Files
eugenios/kernel.s

188 lines
2.4 KiB
ArmAsm

.global kernel_main, __bss, __bss_end, __stack_top
.section .rodata
panic_message: .asciz "\nPanic"
.equ PANIC_MESSAGE_SIZE, . - panic_message
.section .text
bzero:
la t0, __bss
la t1, __bss_end
.Lbzero_loop:
bgt t0, t1, .Lbzero_end
sw zero, (t0)
addi t0, t0, 4
.Lbzero_end:
ret
.type kernel_main, @function
kernel_main:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
la t0, kernel_entry
csrw stvec, t0
unimp
.Lkernel_main:
j .Lkernel_main
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
.balign 4
.type kernel_entry, @function
kernel_entry:
csrw sscratch, sp
addi sp, sp, -4 * 31
sw ra, 0(sp)
sw gp, 4(sp)
sw tp, 8(sp)
sw t0, 12(sp)
sw t1, 16(sp)
sw t2, 20(sp)
sw t3, 24(sp)
sw t4, 28(sp)
sw t5, 32(sp)
sw t6, 36(sp)
sw a0, 40(sp)
sw a1, 44(sp)
sw a2, 48(sp)
sw a3, 52(sp)
sw a4, 56(sp)
sw a5, 60(sp)
sw a6, 64(sp)
sw a7, 68(sp)
sw s0, 72(sp)
sw s1, 76(sp)
sw s2, 80(sp)
sw s3, 84(sp)
sw s4, 88(sp)
sw s5, 92(sp)
sw s6, 96(sp)
sw s7, 100(sp)
sw s8, 104(sp)
sw s9, 108(sp)
sw s10, 112(sp)
sw s11, 116(sp)
csrr a0, sscratch
sw a0, 120(sp)
mv a0, sp
call handle_trap
lw ra, 0(sp)
lw gp, 4(sp)
lw tp, 8(sp)
lw t0, 12(sp)
lw t1, 16(sp)
lw t2, 20(sp)
lw t3, 24(sp)
lw t4, 28(sp)
lw t5, 32(sp)
lw t6, 36(sp)
lw a0, 40(sp)
lw a1, 44(sp)
lw a2, 48(sp)
lw a3, 52(sp)
lw a4, 56(sp)
lw a5, 60(sp)
lw a6, 64(sp)
lw a7, 68(sp)
lw s0, 72(sp)
lw s1, 76(sp)
lw s2, 80(sp)
lw s3, 84(sp)
lw s4, 88(sp)
lw s5, 92(sp)
lw s6, 96(sp)
lw s7, 100(sp)
lw s8, 104(sp)
lw s9, 108(sp)
lw s10, 112(sp)
lw s11, 116(sp)
lw sp, 120(sp)
sret
.type handle_trap, @function
handle_trap:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
csrr t0, scause
csrr t1, stval
csrr t2, sepc
li a0, PANIC_MESSAGE_SIZE
la a1, panic_message
call write_s
li a0, ' '
call write_c
csrr a0, scause
call write_i
call separator
call write_c
csrr a0, stval
call write_i
call separator
call write_c
csrr a0, sepc
call write_i
call panic
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
.type panic, @function
panic:
# Prologue.
addi sp, sp, -32
sw ra, 28(sp)
sw s0, 24(sp)
addi s0, sp, 32
li a0, '\n'
call write_c
.Lpanic:
j .Lpanic
# Epilogue.
lw ra, 28(sp)
lw s0, 24(sp)
addi sp, sp, 32
ret
.section .text.boot
boot:
la a0, __stack_top
mv sp, a0 # Set the stack pointer
call bzero
j kernel_main