From 4cabd1d9625c7d88acd143f4021fbef75394f154 Mon Sep 17 00:00:00 2001 From: Matthew Leach Date: Fri, 21 Sep 2012 18:56:02 +0100 Subject: [PATCH] ARM: 7539/1: kexec: scan for dtb magic in segments This patch allows a dtb to be passed to a new kernel using the kexec mechinism. When loading segments from userspace, scan each segment's first four bytes for the dtb magic. If this is found set the kexec_boot_atags parameter to the relocate_kernel code to the phyical address of this segment. Reviewed-by: Simon Horman Reviewed-by: Will Deacon Signed-off-by: Matthew Leach Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/machine_kexec.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index dfcdb9f7c126..dee34efca748 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -32,6 +33,24 @@ static atomic_t waiting_for_crash_ipi; int machine_kexec_prepare(struct kimage *image) { + struct kexec_segment *current_segment; + __be32 header; + int i, err; + + /* + * No segment at default ATAGs address. try to locate + * a dtb using magic. + */ + for (i = 0; i < image->nr_segments; i++) { + current_segment = &image->segment[i]; + + err = get_user(header, (__be32*)current_segment->buf); + if (err) + return err; + + if (be32_to_cpu(header) == OF_DT_HEADER) + kexec_boot_atags = current_segment->mem; + } return 0; } @@ -122,7 +141,9 @@ void machine_kexec(struct kimage *image) kexec_start_address = image->start; kexec_indirection_page = page_list; kexec_mach_type = machine_arch_type; - kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET; + if (!kexec_boot_atags) + kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET; + /* copy our kernel relocation code to the control code page */ memcpy(reboot_code_buffer, -- 2.20.1