ARM: MXS: fix breakage for non-DT boards

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@pengutronix.de>
Tested-by: Bastian Krause <bst@pengutronix.de>
Link: https://lore.barebox.org/20221011114927.546670-1-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 15 insertions, 1 deletions

diff --git a/arch/arm/boards/crystalfontz-cfa10036/lowlevel.c b/arch/arm/boards/crystalfontz-cfa10036/lowlevel.c
index 92b42aa893..8ebea0fedc 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);
 }