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223 lines
4.4 KiB
223 lines
4.4 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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/* |
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* Copyright (C) 2019 FORTH-ICS/CARV |
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* Nick Kossifidis <mick@ics.forth.gr> |
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*/ |
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#include <asm/asm.h> /* For RISCV_* and REG_* macros */ |
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#include <asm/csr.h> /* For CSR_* macros */ |
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#include <asm/page.h> /* For PAGE_SIZE */ |
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#include <linux/linkage.h> /* For SYM_* macros */ |
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.section ".rodata" |
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SYM_CODE_START(riscv_kexec_relocate) |
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/* |
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* s0: Pointer to the current entry |
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* s1: (const) Phys address to jump to after relocation |
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* s2: (const) Phys address of the FDT image |
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* s3: (const) The hartid of the current hart |
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* s4: Pointer to the destination address for the relocation |
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* s5: (const) Number of words per page |
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* s6: (const) 1, used for subtraction |
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* s7: (const) kernel_map.va_pa_offset, used when switching MMU off |
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* s8: (const) Physical address of the main loop |
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* s9: (debug) indirection page counter |
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* s10: (debug) entry counter |
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* s11: (debug) copied words counter |
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*/ |
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mv s0, a0 |
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mv s1, a1 |
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mv s2, a2 |
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mv s3, a3 |
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mv s4, zero |
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li s5, (PAGE_SIZE / RISCV_SZPTR) |
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li s6, 1 |
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mv s7, a4 |
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mv s8, zero |
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mv s9, zero |
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mv s10, zero |
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mv s11, zero |
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/* Disable / cleanup interrupts */ |
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csrw CSR_SIE, zero |
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csrw CSR_SIP, zero |
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/* |
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* When we switch SATP.MODE to "Bare" we'll only |
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* play with physical addresses. However the first time |
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* we try to jump somewhere, the offset on the jump |
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* will be relative to pc which will still be on VA. To |
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* deal with this we set stvec to the physical address at |
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* the start of the loop below so that we jump there in |
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* any case. |
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*/ |
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la s8, 1f |
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sub s8, s8, s7 |
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csrw CSR_STVEC, s8 |
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/* Process entries in a loop */ |
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.align 2 |
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1: |
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addi s10, s10, 1 |
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REG_L t0, 0(s0) /* t0 = *image->entry */ |
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addi s0, s0, RISCV_SZPTR /* image->entry++ */ |
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/* IND_DESTINATION entry ? -> save destination address */ |
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andi t1, t0, 0x1 |
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beqz t1, 2f |
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andi s4, t0, ~0x1 |
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j 1b |
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2: |
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/* IND_INDIRECTION entry ? -> update next entry ptr (PA) */ |
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andi t1, t0, 0x2 |
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beqz t1, 2f |
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andi s0, t0, ~0x2 |
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addi s9, s9, 1 |
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csrw CSR_SATP, zero |
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jalr zero, s8, 0 |
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2: |
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/* IND_DONE entry ? -> jump to done label */ |
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andi t1, t0, 0x4 |
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beqz t1, 2f |
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j 4f |
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2: |
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/* |
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* IND_SOURCE entry ? -> copy page word by word to the |
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* destination address we got from IND_DESTINATION |
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*/ |
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andi t1, t0, 0x8 |
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beqz t1, 1b /* Unknown entry type, ignore it */ |
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andi t0, t0, ~0x8 |
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mv t3, s5 /* i = num words per page */ |
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3: /* copy loop */ |
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REG_L t1, (t0) /* t1 = *src_ptr */ |
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REG_S t1, (s4) /* *dst_ptr = *src_ptr */ |
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addi t0, t0, RISCV_SZPTR /* stc_ptr++ */ |
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addi s4, s4, RISCV_SZPTR /* dst_ptr++ */ |
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sub t3, t3, s6 /* i-- */ |
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addi s11, s11, 1 /* c++ */ |
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beqz t3, 1b /* copy done ? */ |
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j 3b |
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4: |
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/* Pass the arguments to the next kernel / Cleanup*/ |
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mv a0, s3 |
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mv a1, s2 |
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mv a2, s1 |
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/* Cleanup */ |
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mv a3, zero |
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mv a4, zero |
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mv a5, zero |
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mv a6, zero |
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mv a7, zero |
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mv s0, zero |
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mv s1, zero |
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mv s2, zero |
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mv s3, zero |
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mv s4, zero |
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mv s5, zero |
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mv s6, zero |
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mv s7, zero |
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mv s8, zero |
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mv s9, zero |
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mv s10, zero |
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mv s11, zero |
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mv t0, zero |
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mv t1, zero |
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mv t2, zero |
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mv t3, zero |
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mv t4, zero |
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mv t5, zero |
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mv t6, zero |
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csrw CSR_SEPC, zero |
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csrw CSR_SCAUSE, zero |
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csrw CSR_SSCRATCH, zero |
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/* |
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* Make sure the relocated code is visible |
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* and jump to the new kernel |
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*/ |
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fence.i |
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jalr zero, a2, 0 |
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SYM_CODE_END(riscv_kexec_relocate) |
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riscv_kexec_relocate_end: |
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/* Used for jumping to crashkernel */ |
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.section ".text" |
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SYM_CODE_START(riscv_kexec_norelocate) |
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/* |
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* s0: (const) Phys address to jump to |
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* s1: (const) Phys address of the FDT image |
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* s2: (const) The hartid of the current hart |
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* s3: (const) kernel_map.va_pa_offset, used when switching MMU off |
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*/ |
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mv s0, a1 |
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mv s1, a2 |
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mv s2, a3 |
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mv s3, a4 |
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/* Disable / cleanup interrupts */ |
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csrw CSR_SIE, zero |
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csrw CSR_SIP, zero |
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/* Switch to physical addressing */ |
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la s4, 1f |
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sub s4, s4, s3 |
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csrw CSR_STVEC, s4 |
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csrw CSR_SATP, zero |
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.align 2 |
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1: |
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/* Pass the arguments to the next kernel / Cleanup*/ |
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mv a0, s2 |
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mv a1, s1 |
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mv a2, s0 |
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/* Cleanup */ |
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mv a3, zero |
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mv a4, zero |
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mv a5, zero |
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mv a6, zero |
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mv a7, zero |
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mv s0, zero |
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mv s1, zero |
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mv s2, zero |
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mv s3, zero |
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mv s4, zero |
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mv s5, zero |
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mv s6, zero |
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mv s7, zero |
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mv s8, zero |
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mv s9, zero |
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mv s10, zero |
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mv s11, zero |
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mv t0, zero |
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mv t1, zero |
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mv t2, zero |
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mv t3, zero |
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mv t4, zero |
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mv t5, zero |
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mv t6, zero |
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csrw CSR_SEPC, zero |
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csrw CSR_SCAUSE, zero |
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csrw CSR_SSCRATCH, zero |
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jalr zero, a2, 0 |
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SYM_CODE_END(riscv_kexec_norelocate) |
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.section ".rodata" |
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SYM_DATA(riscv_kexec_relocate_size, |
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.long riscv_kexec_relocate_end - riscv_kexec_relocate) |
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