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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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4cd9d6f774
Currently, the atags used by kexec are fixed to the ones originally used to boot the kernel. This is less than ideal as changing the commandline, initrd and other options would be a useful feature. This patch exports the atags used for the current kernel to userspace through an "atags" file in procfs. The presence of the file is controlled by its own Kconfig option and cleans up several ifdef blocks into a separate file. The tags for the new kernel are assumed to be at a fixed location before the kernel image itself. The location of the tags used to boot the original kernel is unimportant and no longer saved. Based on a patch from Uli Luckas <u.luckas@road.de> Signed-off-by: Richard Purdie <rpurdie@rpsys.net> Acked-by: Uli Luckas <u.luckas@road.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
80 lines
1.2 KiB
ArmAsm
80 lines
1.2 KiB
ArmAsm
/*
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* relocate_kernel.S - put the kernel image in place to boot
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*/
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#include <asm/kexec.h>
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.globl relocate_new_kernel
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relocate_new_kernel:
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ldr r0,kexec_indirection_page
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ldr r1,kexec_start_address
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0: /* top, read another word for the indirection page */
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ldr r3, [r0],#4
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/* Is it a destination page. Put destination address to r4 */
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tst r3,#1,0
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beq 1f
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bic r4,r3,#1
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b 0b
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1:
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/* Is it an indirection page */
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tst r3,#2,0
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beq 1f
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bic r0,r3,#2
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b 0b
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1:
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/* are we done ? */
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tst r3,#4,0
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beq 1f
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b 2f
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1:
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/* is it source ? */
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tst r3,#8,0
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beq 0b
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bic r3,r3,#8
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mov r6,#1024
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9:
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ldr r5,[r3],#4
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str r5,[r4],#4
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subs r6,r6,#1
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bne 9b
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b 0b
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2:
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/* Jump to relocated kernel */
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mov lr,r1
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mov r0,#0
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ldr r1,kexec_mach_type
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ldr r2,kexec_boot_atags
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mov pc,lr
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.globl kexec_start_address
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kexec_start_address:
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.long 0x0
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.globl kexec_indirection_page
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kexec_indirection_page:
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.long 0x0
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.globl kexec_mach_type
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kexec_mach_type:
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.long 0x0
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/* phy addr of the atags for the new kernel */
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.globl kexec_boot_atags
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kexec_boot_atags:
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.long 0x0
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relocate_new_kernel_end:
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.globl relocate_new_kernel_size
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relocate_new_kernel_size:
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.long relocate_new_kernel_end - relocate_new_kernel
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