![Max Filippov](/assets/img/avatar_default.png)
vmlinux.lds.S doesn't do anything special with literals, so instead of keeping them separate put them into the corresponding text sections. Drop explicit .literal sections from the vmlinux.lds.S, use standard section macros. Mark literal pool locations in the assembly sources. Unfortunately assembler doesn't put literals into .init sections and external libgcc may still have .literal sections, so sed transformation to the linker script is still needed. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
252 lines
4.6 KiB
ArmAsm
252 lines
4.6 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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#include <variant/core.h>
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#include <asm/regs.h>
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#include <asm/asmmacro.h>
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#include <asm/cacheasm.h>
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/*
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* RB-Data: RedBoot data/bss
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* P: Boot-Parameters
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* L: Kernel-Loader
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*
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* The Linux-Kernel image including the loader must be loaded
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* to a position so that the kernel and the boot parameters
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* can fit in the space before the load address.
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* ______________________________________________________
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* |_RB-Data_|_P_|__________|_L_|___Linux-Kernel___|______|
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* ^
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* ^ Load address
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* ______________________________________________________
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* |___Linux-Kernel___|_P_|_L_|___________________________|
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*
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* The loader copies the parameter to the position that will
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* be the end of the kernel and itself to the end of the
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* parameter list.
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*/
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/* Make sure we have enough space for the 'uncompressor' */
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#define STACK_SIZE 32768
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#define HEAP_SIZE (131072*4)
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# a2: Parameter list
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# a3: Size of parameter list
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.section .start, "ax"
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.globl __start
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/* this must be the first byte of the loader! */
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__start:
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entry sp, 32 # we do not intend to return
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_call0 _start
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__start_a0:
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.align 4
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.section .text, "ax"
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.literal_position
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.begin literal_prefix .text
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/* put literals in here! */
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.globl _start
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_start:
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/* 'reset' window registers */
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movi a4, 1
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wsr a4, ps
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rsync
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rsr a5, windowbase
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ssl a5
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sll a4, a4
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wsr a4, windowstart
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rsync
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movi a4, 0x00040000
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wsr a4, ps
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rsync
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/* copy the loader to its address
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* Note: The loader itself is a very small piece, so we assume we
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* don't partially overlap. We also assume (even more important)
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* that the kernel image is out of the way. Usually, when the
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* load address of this image is not at an arbitrary address,
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* but aligned to some 10K's we shouldn't overlap.
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*/
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/* Note: The assembler cannot relax "addi a0, a0, ..." to an
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l32r, so we load to a4 first. */
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# addi a4, a0, __start - __start_a0
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# mov a0, a4
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movi a4, __start
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movi a5, __start_a0
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add a4, a0, a4
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sub a0, a4, a5
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movi a4, __start
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movi a5, __reloc_end
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# a0: address where this code has been loaded
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# a4: compiled address of __start
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# a5: compiled end address
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mov.n a7, a0
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mov.n a8, a4
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1:
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l32i a10, a7, 0
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l32i a11, a7, 4
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s32i a10, a8, 0
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s32i a11, a8, 4
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l32i a10, a7, 8
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l32i a11, a7, 12
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s32i a10, a8, 8
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s32i a11, a8, 12
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addi a8, a8, 16
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addi a7, a7, 16
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blt a8, a5, 1b
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/* We have to flush and invalidate the caches here before we jump. */
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#if XCHAL_DCACHE_IS_WRITEBACK
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___flush_dcache_all a5 a6
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#endif
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___invalidate_icache_all a5 a6
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isync
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movi a11, _reloc
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jx a11
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.globl _reloc
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_reloc:
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/* RedBoot is now at the end of the memory, so we don't have
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* to copy the parameter list. Keep the code around; in case
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* we need it again. */
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#if 0
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# a0: load address
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# a2: start address of parameter list
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# a3: length of parameter list
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# a4: __start
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/* copy the parameter list out of the way */
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movi a6, _param_start
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add a3, a2, a3
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2:
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l32i a8, a2, 0
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s32i a8, a6, 0
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addi a2, a2, 4
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addi a6, a6, 4
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blt a2, a3, 2b
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#endif
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/* clear BSS section */
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movi a6, __bss_start
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movi a7, __bss_end
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movi.n a5, 0
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3:
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s32i a5, a6, 0
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addi a6, a6, 4
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blt a6, a7, 3b
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movi a5, -16
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movi a1, _stack + STACK_SIZE
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and a1, a1, a5
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/* Uncompress the kernel */
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# a0: load address
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# a2: boot parameter
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# a4: __start
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movi a3, __image_load
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sub a4, a3, a4
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add a8, a0, a4
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# a1 Stack
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# a8(a4) Load address of the image
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movi a6, _image_start
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movi a10, _image_end
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movi a7, 0x1000000
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sub a11, a10, a6
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movi a9, complen
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s32i a11, a9, 0
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movi a0, 0
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# a6 destination
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# a7 maximum size of destination
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# a8 source
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# a9 ptr to length
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.extern gunzip
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movi a4, gunzip
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beqz a4, 1f
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callx4 a4
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j 2f
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# a6 destination start
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# a7 maximum size of destination
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# a8 source start
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# a9 ptr to length
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# a10 destination end
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1:
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l32i a9, a8, 0
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l32i a11, a8, 4
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s32i a9, a6, 0
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s32i a11, a6, 4
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l32i a9, a8, 8
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l32i a11, a8, 12
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s32i a9, a6, 8
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s32i a11, a6, 12
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addi a6, a6, 16
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addi a8, a8, 16
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blt a6, a10, 1b
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/* jump to the kernel */
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2:
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#if XCHAL_DCACHE_IS_WRITEBACK
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___flush_dcache_all a5 a6
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#endif
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___invalidate_icache_all a5 a6
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isync
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# a2 Boot parameter list
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movi a0, _image_start
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jx a0
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.align 16
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.data
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.globl avail_ram
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avail_ram:
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.long _heap
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.globl end_avail
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end_avail:
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.long _heap + HEAP_SIZE
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.comm _stack, STACK_SIZE
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.comm _heap, HEAP_SIZE
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.globl end_avail
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.comm complen, 4
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.end literal_prefix
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