Hi Marek, Lukasz,
On 31.07.23 10:06, Lukasz Majewski wrote:
On Sat, 29 Jul 2023 15:30:10 +0200
Marek Vasut <ma...@denx.de> wrote:
The MXS starts with CPSR V bit set, which makes the CPU jump to high
vectors in case of an exception. Those high vectors are located at
0xffff0000, which is where the BootROM exception table is located as
well. U-Boot should handle exceptions on its own using its own
exception handling code, which is located at 0x0, i.e. at low
vectors. Clear the CPSR V bit, so that the CPU would jump to low
vectors on exception instead, and therefore run the U-Boot exception
handling code.
Signed-off-by: Marek Vasut <ma...@denx.de>
---
Cc: "NXP i.MX U-Boot Team" <uboot-...@nxp.com>
Cc: Fabio Estevam <feste...@gmail.com>
Cc: Lukasz Majewski <lu...@denx.de>
Cc: Stefano Babic <sba...@denx.de>
---
arch/arm/cpu/arm926ejs/mxs/mxs.c | 3 +++
arch/arm/cpu/arm926ejs/mxs/spl_boot.c | 4 ++++
2 files changed, 7 insertions(+)
diff --git a/arch/arm/cpu/arm926ejs/mxs/mxs.c
b/arch/arm/cpu/arm926ejs/mxs/mxs.c index 4d21e3df76e..d64a8328b04
100644 --- a/arch/arm/cpu/arm926ejs/mxs/mxs.c
+++ b/arch/arm/cpu/arm926ejs/mxs/mxs.c
@@ -85,6 +85,9 @@ void mx28_fixup_vt(uint32_t start_addr)
/* cppcheck-suppress nullPointer */
vt[i + 8] = start_addr + (4 * i);
}
+
+ /* Make sure ARM core points to low vectors */
+ set_cr(get_cr() & ~CR_V);
}
#ifdef CONFIG_ARCH_MISC_INIT
diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c
b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c index
5598c552ab9..4a7dfc6a2ae 100644 ---
a/arch/arm/cpu/arm926ejs/mxs/spl_boot.c +++
b/arch/arm/cpu/arm926ejs/mxs/spl_boot.c @@ -17,6 +17,7 @@
#include <asm/arch/sys_proto.h>
#include <asm/gpio.h>
#include <asm/sections.h>
+#include <asm/system.h>
#include <linux/compiler.h>
#include "mxs_init.h"
@@ -104,6 +105,9 @@ static void mxs_spl_fixup_vectors(void)
/* cppcheck-suppress nullPointer */
memcpy(0x0, &_start, 0x60);
+
+ /* Make sure ARM core points to low vectors */
+ set_cr(get_cr() & ~CR_V);
}
static void mxs_spl_console_init(void)
Reviewed-by: Lukasz Majewski <lu...@denx.de>
Thanks for raising my attention to this older patch, but it breaks
exaclty the xea board:
+{standard input}: Assembler messages:
+{standard input}:214: Error: selected processor does not support `mrc
p15,0,r3,c1,c0,0' in Thumb mode
+{standard input}:249: Error: selected processor does not support `mcr
p15,0,r3,c1,c0,0' in Thumb mode
+{standard input}:157: Error: selected processor does not support `mrc
p15,0,r3,c1,c0,0' in Thumb mode
+{standard input}:188: Error: selected processor does not support `mcr
p15,0,r3,c1,c0,0' in Thumb mode
Can you check it ?
Regards,
Stefano
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