033b8ffe3f
This patch resolves a kexec boot failure that can occur because no ATAGs are passed in to the kexec'd kernel. Currently the newly-kexec'd kernel may fail if it requires specific ATAGs, or it may fail because the fixed memory location at which it expects to find the ATAGs may contain random data instead of ATAGs. The patch ensures that any ATAGs passed to the current kernel at boot time are copied to a static buffer, and are copied back when kexec copies the new kernel into place. Thus the new kernel sees the same ATAGs from kexec and the boot loader. The boot parameters are copied without regard to type, content, or length -- this patch's scope is limited soley to saving and restoring a fixed-size block of memory containing the kernel's boot parameters. Additional functionality to examine, alter, or replace the ATAGs (using kexec, for example) can be implemented by manipulating the static buffer containing the preserved ATAGs. Note: the size of the buffer (1.5KB) is selected to comfortably hold one of each ATAG type, including a maximum-length command line and the maximum number of ATAG_MEM structures currently supported by the kernel. Should an ATAG list exceed that limit, the list will be silently truncated to that limit (to do other- wise at that point in the boot process would make a simple problem exceedingly complicated). [Note: this is the same patch as 4579, modified to accomodate the ATAG changes introduced in 2.6.23] Signed-off-by: Mike Westerhof <mwester at dls.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
102 lines
1.6 KiB
ArmAsm
102 lines
1.6 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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/* Move boot params back to where the kernel expects them */
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ldr r0,kexec_boot_params_address
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teq r0,#0
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beq 8f
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ldr r1,kexec_boot_params_copy
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mov r6,#KEXEC_BOOT_PARAMS_SIZE/4
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7:
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ldr r5,[r1],#4
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str r5,[r0],#4
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subs r6,r6,#1
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bne 7b
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8:
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/* Boot params moved, now go on with the 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_params_address
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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 where new kernel will expect to find boot params */
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.globl kexec_boot_params_address
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kexec_boot_params_address:
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.long 0x0
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/* phy addr where old kernel put a copy of orig boot params */
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.globl kexec_boot_params_copy
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kexec_boot_params_copy:
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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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