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https://github.com/handsomezhuzhu/2025-yatcpu.git
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118 lines
2.2 KiB
ArmAsm
118 lines
2.2 KiB
ArmAsm
# Copyright 2021 Howard Lau
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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.section .text.init
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.globl _start
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_start:
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li sp, 0x10000000 # Initialize stack pointer
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call main # Jump to main function
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loop:
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j loop # Loop forever
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.globl enable_interrupt
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enable_interrupt:
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la t0, __trap_entry
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csrrw t1, mtvec, t0 # setup trap vector base
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li t0, 0x1888
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csrrw t1, mstatus, t0 # enable interrupt
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ret
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.globl enable_paging
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enable_paging:
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li t0, 0x80000005 # ppn << 12 = 0x005000
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csrw satp, t0
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ret
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.globl get_mtval
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get_mtval:
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csrr a0, mtval
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ret
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.globl get_epc
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get_epc:
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csrr a0, mepc
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ret
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.weak trap_handler
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tran_handler:
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ret
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__trap_entry:
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csrw mscratch, sp
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addi sp, sp, -128
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sw ra, 4(sp)
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sw gp, 12(sp)
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sw tp, 16(sp)
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sw t0, 20(sp)
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sw t1, 24(sp)
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sw t2, 28(sp)
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sw tp, 32(sp)
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sw s1, 36(sp)
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sw a0, 40(sp)
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sw a1, 44(sp)
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sw a2, 48(sp)
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sw a3, 52(sp)
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sw a4, 56(sp)
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sw a5, 60(sp)
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sw a6, 64(sp)
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sw a7, 68(sp)
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sw s2, 72(sp)
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sw s3, 76(sp)
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sw s4, 80(sp)
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sw s5, 84(sp)
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sw s6, 88(sp)
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sw s7, 92(sp)
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sw s8, 96(sp)
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sw s9, 100(sp)
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sw s10, 104(sp)
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sw s11, 108(sp)
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sw t3, 112(sp)
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sw t4, 116(sp)
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sw t5, 120(sp)
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sw t6, 124(sp)
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csrr a0, mepc
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csrr a1, mcause
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call trap_handler
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lw ra, 4(sp)
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lw gp, 12(sp)
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lw tp, 16(sp)
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lw t0, 20(sp)
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lw t1, 24(sp)
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lw t2, 28(sp)
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lw tp, 32(sp)
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lw s1, 36(sp)
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lw a0, 40(sp)
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lw a1, 44(sp)
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lw a2, 48(sp)
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lw a3, 52(sp)
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lw a4, 56(sp)
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lw a5, 60(sp)
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lw a6, 64(sp)
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lw a7, 68(sp)
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lw s2, 72(sp)
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lw s3, 76(sp)
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lw s4, 80(sp)
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lw s5, 84(sp)
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lw s6, 88(sp)
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lw s7, 92(sp)
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lw s8, 96(sp)
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lw s9, 100(sp)
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lw s10, 104(sp)
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lw s11, 108(sp)
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lw t3, 112(sp)
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lw t4, 116(sp)
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lw t5, 120(sp)
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lw t6, 124(sp)
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csrr sp, mscratch
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mret
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