Older big-endian ppc64 kernels don't include the FIXUP_ENDIAN check,
meaning if we kexec from a little-endian kernel the target kernel will
fail to boot.
Returning to big-endian before we enter the target kernel ensures that
the target kernel can boot whether or not it includes FIXUP_ENDIAN.
Signed-off-by: Samuel Mendoza-Jonas <sam...@au1.ibm.com>
---
kexec_trampoline.S | 9 ++++++++-
kexec_trampoline.h | 17 +++++++++++++++--
2 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/kexec_trampoline.S b/kexec_trampoline.S
index a3eb314..29537ab 100644
--- a/kexec_trampoline.S
+++ b/kexec_trampoline.S
@@ -41,6 +41,8 @@
#define r7 7
#define r8 8
#define r9 9
+#define r10 10
+#define r11 11
#ifdef __powerpc64__
#define LOAD ld
@@ -50,8 +52,10 @@
#if defined(__LITTLE_ENDIAN__)
#define STWX_BE stwbrx
+#define BCTR .long 0x2004804e
#elif defined(__BIG_ENDIAN__)
#define STWX_BE stwx
+#define BCTR bctr
#else
#error no endianness defined!
#endif
@@ -89,7 +93,10 @@ start:
li r5,0
mtctr r4
- bctr
+
+ RESET_ENDIAN
+
+ BCTR
. = KERNEL_ADDR_OFFSET
kernel_addr:
diff --git a/kexec_trampoline.h b/kexec_trampoline.h
index 6485c88..909953b 100644
--- a/kexec_trampoline.h
+++ b/kexec_trampoline.h
@@ -27,7 +27,20 @@
/* Fixed offset in device tree for storing the physical ID of the boot CPU */
#define DT_CPU_OFFSET 28
-#ifndef __ASSEMBLY__
+#ifdef __ASSEMBLY__
+#define RESET_ENDIAN \
+ mfmsr r9; \
+ clrldi. r10,r9,63; \
+ beq $+36; /* Already big-endian */ \
+ bcl 20,31,$+4; \
+ mflr r10; \
+ addi r10,r10,28; \
+ mfmsr r11; \
+ xori r11,r11,1; \
+ mtsrr0 r10; \
+ mtsrr1 r11; \
+ rfid;
+#else
extern char __trampoline_start[];
extern char __trampoline_end[];
@@ -48,6 +61,6 @@ static inline void trampoline_set_device_tree(void *p,
unsigned long addr)
*v = addr;
}
-#endif
+#endif /* !__ASSEMBLY__ */
#endif
--
2.4.5
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