Fix the building issue of boot image, and add zImage booting support.

Changes:
1) zImage entry point switches EL2-aarch64 to EL1-aarch32 instead of
kernel entry point.
2) Set ZRELADDR of mach-mmp/Makefile.boot to 8MB.
3) Fix buggy TTBCR setup in arch/arm/boot/compressed/head.S Bits
[2:0] and not [1:0] should be set to 0 as TTBCR.N is a 3-bit field
and non-0 value would result in truncated TTB space and thus limited
virtual space accessible.
4) Kernel defconfig: enable CONFIG_APPENDED_DTB and related settings.
5) Disable stack protector on atags-to-fdt function.
The reason is -fstack-protector-strong generates a stack canary code in
atags_to_fdt(), which accesses __stack_chk_guard in .bss. This violates
the assumption that atags_to_fdt does not access any globals as
explicitly stated in comments before the function invocation in head.S.
The function is called before GOT relocations are performed, thus
__stack_chk_guard is accessed by offset in GOT, not an actual relocated
address. That this might work on many platforms that have accessible
memory at low addresses (similar to a NULL pointer access),but On iap140
the lowest 8MB of physical address space is not accessible to
Non-Security, therefore __stack_chk_guard results in exception.

BUG=25393413
BUG=25421621

Change-Id: I72164e43b2dc400ae7db0e3403e5ae78cd6e5a34

5 files changed, 28 insertions, 6 deletions

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 68c918362b7..128ee0b16eb 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -124,6 +124,14 @@ endif
 ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj)
 asflags-y := -DZIMAGE
 
+ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
+CFLAGS_atags_to_fdt.o := -fno-stack-protector
+CFLAGS_fdt.o := -fno-stack-protector
+CFLAGS_fdt_ro.o := -fno-stack-protector
+CFLAGS_fdt_rw.o := -fno-stack-protector
+CFLAGS_fdt_wip.o := -fno-stack-protector
+endif
+
 # Supply kernel BSS size to the decompressor via a linker symbol.
 KBSS_SZ = $(shell $(CROSS_COMPILE)size $(obj)/../../../../vmlinux | \
 		awk 'END{print $$3}')
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index c0d3977b138..96c0581184c 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -11,6 +11,10 @@
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 
+#ifdef CONFIG_CPU_PXA1908
+#include "../../kernel/entry-el2.S"
+#endif
+
 	.arch	armv7-a
 /*
  * Debugging stuff
@@ -122,7 +126,12 @@
 		.arm				@ Always enter in ARM state
 start:
 		.type	start,#function
+#ifdef CONFIG_CPU_PXA1908
+		.word 0x1400000c		@ b 1f (0x30 forward)
+		.rept 6
+#else
 		.rept	7
+#endif
 		mov	r0, r0
 		.endr
    ARM(		mov	r0, r0		)
@@ -135,6 +144,9 @@ start:
 		.word	_edata			@ zImage end address
  THUMB(		.thumb			)
 1:
+#ifdef CONFIG_CPU_PXA1908
+		el2_setup
+#endif
  ARM_BE8(	setend	be )			@ go BE8 if compiled for BE8
 		mrs	r9, cpsr
 #ifdef CONFIG_ARM_VIRT_EXT
@@ -738,7 +750,7 @@ __armv7_mmu_cache_on:
 		orrne	r0, r0, #1		@ MMU enabled
 		movne	r1, #0xfffffffd		@ domain 0 = client
 		bic     r6, r6, #1 << 31        @ 32-bit translation system
-		bic     r6, r6, #3 << 0         @ use only ttbr0
+		bic     r6, r6, #7 << 0         @ use only ttbr0
 		mcrne	p15, 0, r3, c2, c0, 0	@ load page table pointer
 		mcrne	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
 		mcr	p15, 0, r0, c7, c5, 4	@ ISB
diff --git a/arch/arm/configs/armadillo_edge_defconfig b/arch/arm/configs/armadillo_edge_defconfig
index 744535e167c..27e695badd6 100644
--- a/arch/arm/configs/armadillo_edge_defconfig
+++ b/arch/arm/configs/armadillo_edge_defconfig
@@ -1,4 +1,4 @@
-#
+
 # Automatically generated file; DO NOT EDIT.
 # Linux/arm 3.14.35 Kernel Configuration
 #
@@ -496,10 +496,12 @@ CONFIG_IOMMU_HELPER=y
 CONFIG_USE_OF=y
 CONFIG_ATAGS=y
 # CONFIG_DEPRECATED_PARAM_STRUCT is not set
-# CONFIG_BUILD_ARM_APPENDED_DTB_IMAGE is not set
+CONFIG_BUILD_ARM_APPENDED_DTB_IMAGE=y
+CONFIG_BUILD_ARM_APPENDED_DTB_IMAGE_NAMES="pxa1908-dkb"
 CONFIG_ZBOOT_ROM_TEXT=0
 CONFIG_ZBOOT_ROM_BSS=0
-# CONFIG_ARM_APPENDED_DTB is not set
+CONFIG_ARM_APPENDED_DTB=y
+CONFIG_ARM_ATAG_DTB_COMPAT=y
 CONFIG_CMDLINE="rdinit=/busybox/rdinit console=ttyS0,115200 mem=512M earlyprintk uart_dma"
 CONFIG_CMDLINE_FROM_BOOTLOADER=y
 # CONFIG_CMDLINE_EXTEND is not set
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 845b69ae315..ef60f81183b 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -83,7 +83,7 @@
 
 	__HEAD
 ENTRY(stext)
-#ifdef CONFIG_CPU_PXA1908
+#if defined(CONFIG_CPU_PXA1908) && !defined(CONFIG_ARM_APPENDED_DTB)
 	head_arm64_arg_fix
 	el2_setup
 #endif
diff --git a/arch/arm/mach-mmp/Makefile.boot b/arch/arm/mach-mmp/Makefile.boot
index 257194382f5..e928f86ae4d 100644
--- a/arch/arm/mach-mmp/Makefile.boot
+++ b/arch/arm/mach-mmp/Makefile.boot
@@ -1,5 +1,5 @@
 
-__ADDRBASE := 0x00000000
+__ADDRBASE := 0x00800000
 
 __ZRELADDR := $(shell /bin/bash -c 'printf "0x%08x" \
 	$$[$(TEXT_OFFSET) + $(__ADDRBASE)]')