powerpc/boot: Add support for 64bit little endian wrapper
The code is only slightly modified : entry points now use the
FIXUP_ENDIAN trampoline to switch endian order. The 32bit wrapper
is kept for big endian kernels and 64bit is enforced for little
endian kernels with a PPC64_BOOT_WRAPPER config option.
The linker script is generated using the kernel preprocessor flags
to make use of the CONFIG_* definitions and the wrapper script is
modified to take into account the new elf64ppc format.
Finally, the zImage file is compiled as a position independent
executable (-pie) which makes it loadable at any address by the
firmware.
Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/boot/ppc_asm.h b/arch/powerpc/boot/ppc_asm.h
index eb0e98b..35ea60c 100644
--- a/arch/powerpc/boot/ppc_asm.h
+++ b/arch/powerpc/boot/ppc_asm.h
@@ -62,4 +62,16 @@
#define SPRN_TBRL 268
#define SPRN_TBRU 269
+#define FIXUP_ENDIAN \
+ tdi 0, 0, 0x48; /* Reverse endian of b . + 8 */ \
+ b $+36; /* Skip trampoline if endian is good */ \
+ .long 0x05009f42; /* bcl 20,31,$+4 */ \
+ .long 0xa602487d; /* mflr r10 */ \
+ .long 0x1c004a39; /* addi r10,r10,28 */ \
+ .long 0xa600607d; /* mfmsr r11 */ \
+ .long 0x01006b69; /* xori r11,r11,1 */ \
+ .long 0xa6035a7d; /* mtsrr0 r10 */ \
+ .long 0xa6037b7d; /* mtsrr1 r11 */ \
+ .long 0x2400004c /* rfid */
+
#endif /* _PPC64_PPC_ASM_H */