From 033b8ffe3f1ea8174d51d125838ac6deea60f63f Mon Sep 17 00:00:00 2001 From: Mike Westerhof Date: Thu, 11 Oct 2007 03:18:14 +0100 Subject: [ARM] 4599/1: Preserve ATAG list for use with kexec (2.6.23) 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 Signed-off-by: Russell King --- include/asm-arm/kexec.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/asm-arm/kexec.h b/include/asm-arm/kexec.h index b5b030ef633d..46dcc4d0b9bd 100644 --- a/include/asm-arm/kexec.h +++ b/include/asm-arm/kexec.h @@ -14,6 +14,8 @@ #define KEXEC_ARCH KEXEC_ARCH_ARM +#define KEXEC_BOOT_PARAMS_SIZE 1536 + #ifndef __ASSEMBLY__ struct kimage; -- cgit v1.2.1