[PATCH master v3 1/2] ARM: MXS: fix breakage for non-DT boards

[Ahmad Fatoum]

boarddata, the third argument passed from barebox PBL to barebox proper,
is usually either a pointer to an optionally compressed flattened device tree
or a machien type integer casted to a pointer.

In order to support device trees located in the first 8192 bytes of
address space, barebox has been trying to dereference boarddata, before
falling back to treating it as integer.

This resulted in breakage as boarddata may be an integer not divisible
by 4 and thus an unaligned exception would occur.

The already existing barebox_arm_boarddata mechanism sidesteps this
issue: With it, the machine type integer is not passed as is, but the
address of a suitably aligned structure that contains it is passed
instead.

Searching for MACH_TYPE in arch/arm/boards shows 5 boards to be
affected in-tree, which are all fixed with this commit.

Fixes: 390bc7834ffc ("ARM: start: check for machine type last")
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
v2 -> v3:
  - move variable reference into non-naked noinline function (Sascha)
v1 -> v2:
  - Do full relocation instead of get_runtime_offset(). This is
    required, because GCC[1] generated a pc-relative reference
    to boarddata as it's in the same translation unit and as
    such get_runtime_offset() being added was wrong.
    Instead of relying on compiler whims, we instead set up
    a full C environment and play it safe.
  -  s/MACHINE_TYPE/MACH_TYPE/ (Bastian)
---
 arch/arm/boards/chumby_falconwing/lowlevel.c     | 16 +++++++++++++++-
 arch/arm/boards/crystalfontz-cfa10036/lowlevel.c | 16 +++++++++++++++-
 arch/arm/boards/freescale-mx23-evk/lowlevel.c    | 16 +++++++++++++++-
 arch/arm/boards/imx233-olinuxino/lowlevel.c      | 15 ++++++++++++++-
 arch/arm/boards/karo-tx28/lowlevel.c             | 15 ++++++++++++++-
 5 files changed, 73 insertions(+), 5 deletions(-)

diff --git a/arch/arm/boards/chumby_falconwing/lowlevel.c b/arch/arm/boards/chumby_falconwing/lowlevel.c
index 091dd1955260..f0c3143e8d03 100644
--- a/arch/arm/boards/chumby_falconwing/lowlevel.c
+++ b/arch/arm/boards/chumby_falconwing/lowlevel.c
@@ -7,8 +7,22 @@
 #include <mach/imx23-regs.h>
 #include <generated/mach-types.h>
 
+static noinline void continue_imx_entry(size_t size)
+{
+	static struct barebox_arm_boarddata boarddata = {
+		.magic = BAREBOX_ARM_BOARDDATA_MAGIC,
+		.machine = MACH_TYPE_CHUMBY,
+	};
+
+	barebox_arm_entry(IMX_MEMORY_BASE, size, &boarddata);
+}
+
 ENTRY_FUNCTION(start_chumby_falconwing, r0, r1, r2)
 {
 	arm_cpu_lowlevel_init();
-	barebox_arm_entry(IMX_MEMORY_BASE, SZ_64M, (void *)MACH_TYPE_CHUMBY);
+
+	relocate_to_current_adr();
+	setup_c();
+
+	continue_imx_entry(SZ_64M);
 }
diff --git a/arch/arm/boards/crystalfontz-cfa10036/lowlevel.c b/arch/arm/boards/crystalfontz-cfa10036/lowlevel.c
index 92b42aa89350..8ebea0fedc9c 100644
--- a/arch/arm/boards/crystalfontz-cfa10036/lowlevel.c
+++ b/arch/arm/boards/crystalfontz-cfa10036/lowlevel.c
@@ -7,8 +7,22 @@
 #include <mach/imx28-regs.h>
 #include <generated/mach-types.h>
 
+static noinline void continue_imx_entry(size_t size)
+{
+	static struct barebox_arm_boarddata boarddata = {
+		.magic = BAREBOX_ARM_BOARDDATA_MAGIC,
+		.machine = MACH_TYPE_CFA10036,
+	};
+
+	barebox_arm_entry(IMX_MEMORY_BASE, size, &boarddata);
+}
+
 ENTRY_FUNCTION(start_cfa10036, r0, r1, r2)
 {
 	arm_cpu_lowlevel_init();
-	barebox_arm_entry(IMX_MEMORY_BASE, SZ_128M, (void *)MACH_TYPE_CFA10036);
+
+	relocate_to_current_adr();
+	setup_c();
+
+	continue_imx_entry(SZ_128M);
 }
diff --git a/arch/arm/boards/freescale-mx23-evk/lowlevel.c b/arch/arm/boards/freescale-mx23-evk/lowlevel.c
index 62560bbff733..319e9784a4fd 100644
--- a/arch/arm/boards/freescale-mx23-evk/lowlevel.c
+++ b/arch/arm/boards/freescale-mx23-evk/lowlevel.c
@@ -7,8 +7,22 @@
 #include <asm/barebox-arm.h>
 #include <mach/imx23-regs.h>
 
+static noinline void continue_imx_entry(size_t size)
+{
+	static struct barebox_arm_boarddata boarddata = {
+		.magic = BAREBOX_ARM_BOARDDATA_MAGIC,
+		.machine = MACH_TYPE_MX23EVK,
+	};
+
+	barebox_arm_entry(IMX_MEMORY_BASE, size, &boarddata);
+}
+
 ENTRY_FUNCTION(start_imx23_evk, r0, r1, r2)
 {
 	arm_cpu_lowlevel_init();
-	barebox_arm_entry(IMX_MEMORY_BASE, SZ_32M, (void *)MACH_TYPE_MX23EVK);
+
+	relocate_to_current_adr();
+	setup_c();
+
+	continue_imx_entry(SZ_32M);
 }
diff --git a/arch/arm/boards/imx233-olinuxino/lowlevel.c b/arch/arm/boards/imx233-olinuxino/lowlevel.c
index 71fc379f0487..6e80e6889b51 100644
--- a/arch/arm/boards/imx233-olinuxino/lowlevel.c
+++ b/arch/arm/boards/imx233-olinuxino/lowlevel.c
@@ -11,9 +11,22 @@
 #include <mach/iomux.h>
 #include <generated/mach-types.h>
 
+static noinline void continue_imx_entry(size_t size)
+{
+	static struct barebox_arm_boarddata boarddata = {
+		.magic = BAREBOX_ARM_BOARDDATA_MAGIC,
+		.machine = MACH_TYPE_IMX233_OLINUXINO,
+	};
+
+	barebox_arm_entry(IMX_MEMORY_BASE, size, &boarddata);
+}
+
 ENTRY_FUNCTION(start_barebox_olinuxino_imx23, r0, r1, r2)
 {
-	barebox_arm_entry(IMX_MEMORY_BASE, SZ_64M, (void *)MACH_TYPE_IMX233_OLINUXINO);
+	relocate_to_current_adr();
+	setup_c();
+
+	continue_imx_entry(SZ_64M);
 }
 
 static const uint32_t pad_setup[] = {
diff --git a/arch/arm/boards/karo-tx28/lowlevel.c b/arch/arm/boards/karo-tx28/lowlevel.c
index 28d96f3e1a5f..9e90e40926e8 100644
--- a/arch/arm/boards/karo-tx28/lowlevel.c
+++ b/arch/arm/boards/karo-tx28/lowlevel.c
@@ -15,9 +15,22 @@
 #include <stmp-device.h>
 #include <generated/mach-types.h>
 
+static noinline void continue_imx_entry(size_t size)
+{
+	static struct barebox_arm_boarddata boarddata = {
+		.magic = BAREBOX_ARM_BOARDDATA_MAGIC,
+		.machine = MACH_TYPE_TX28,
+	};
+
+	barebox_arm_entry(IMX_MEMORY_BASE, size, &boarddata);
+}
+
 ENTRY_FUNCTION(start_barebox_karo_tx28, r0, r1, r2)
 {
-	barebox_arm_entry(IMX_MEMORY_BASE, SZ_128M, (void *)MACH_TYPE_TX28);
+	relocate_to_current_adr();
+	setup_c();
+
+	continue_imx_entry(SZ_128M);
 }
 
 static const uint32_t iomux_pads[] = {
-- 
2.30.2