0060-HACK-arch-arm-force-ZRELADDR-on-arch-qcom.patch

From fa71139b55e114aa8c3c4823ff8ee7d49ee810d4 Mon Sep 17 00:00:00 2001
From: Mathieu Olivari <mathieu@codeaurora.org>
Date: Wed, 29 Apr 2015 15:21:46 -0700
Subject: [PATCH 60/69] HACK: arch: arm: force ZRELADDR on arch-qcom

ARCH_QCOM is using the ARCH_MULTIPLATFORM option, as now recommended
on most ARM architectures. This automatically calculate ZRELADDR by
masking PHYS_OFFSET with 0xf8000000.

However, on IPQ806x, the first ~20MB of RAM is reserved for the hardware
network accelerators, and the bootloader removes this section from the
layout passed from the ATAGS (when used).

For newer bootloader, when DT is used, this is not a problem, we just
reserve this memory in the device tree. But if the bootloader doesn't
have DT support, then ATAGS have to be used. In this case, the ARM
decompressor will position the kernel in this low mem, which will not be
in the RAM section mapped by the bootloader, which means the kernel will
freeze in the middle of the boot process trying to map the memory.

As a work around, this patch allows disabling AUTO_ZRELADDR when
ARCH_QCOM is selected. It makes the zImage usage possible on bootloaders
which don't support device-tree, which is the case on certain early
IPQ806x based designs.

Signed-off-by: Mathieu Olivari <mathieu@codeaurora.org>
---
 arch/arm/Kconfig                 | 2 +-
 arch/arm/Makefile                | 2 ++
 arch/arm/mach-qcom/Makefile.boot | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-qcom/Makefile.boot

--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -317,7 +317,7 @@ config ARCH_MULTIPLATFORM
 	select ARCH_SELECT_MEMORY_MODEL
 	select ARM_HAS_SG_CHAIN
 	select ARM_PATCH_PHYS_VIRT
-	select AUTO_ZRELADDR
+	select AUTO_ZRELADDR if !ARCH_QCOM
 	select TIMER_OF
 	select COMMON_CLK
 	select GENERIC_IRQ_MULTI_HANDLER
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -237,9 +237,11 @@ MACHINE  := arch/arm/mach-$(word 1,$(mac
 else
 MACHINE  :=
 endif
+ifeq ($(CONFIG_ARCH_QCOM),)
 ifeq ($(CONFIG_ARCH_MULTIPLATFORM),y)
 MACHINE  :=
 endif
+endif
 
 machdirs := $(patsubst %,arch/arm/mach-%/,$(machine-y))
 platdirs := $(patsubst %,arch/arm/plat-%/,$(sort $(plat-y)))
--- /dev/null
+++ b/arch/arm/mach-qcom/Makefile.boot
@@ -0,0 +1 @@
+zreladdr-y+= 0x42208000