[PATCH] examples: fix building on arm32

[Heinrich Schuchardt]

On 1/27/25 05:15, 1425075683 at qq.com wrote:
> From: Liya Huang <1425075683 at qq.com>
>
> Refer to the commit a3c101a61348 ("examples: fix building on arm64")
> fix for arm32. crt0.S does not even build with
> CONFIG_API=y, CONFIG_EXAMPLES=y:
>
>      examples/api/crt0.S: Assembler messages:
>      examples/api/crt0.S:32: Error: lo register required -- `ldr ip,=search_hint'
>      examples/api/crt0.S:33: Error: lo register required -- `str sp,[ip]'
>      examples/api/crt0.S:39: Error: lo register required -- `ldr ip,=syscall_ptr'
>      examples/api/crt0.S:40: Error: lo register required -- `ldr pc,[ip]'
>      make[2]: *** [scripts/Makefile.build:292：examples/api/crt0.o] Error 1
>
> Use valid register names and instructions.

Hello Liva,

Thank you for reporting the issue that you experience and suggesting a
patch.

I am not able to reproduce your problem using

make qemu_arm_defconfig
make menuconfig # to add CONFIG_API=y, CONFIG_EXAMPLES=y
export CROSS_COMPILE=arm-linux-gnueabi-
make

https://developer.arm.com/documentation/den0013/d/Application-Binary-Interfaces/Procedure-Call-Standard
lists IP, SP, PC as aliases for registers R12, R13, R15.

I am using gcc 4.2.0 and binutils 2.43 on Ubuntu 25.04.

Could you, please, share some detail on how to reproduce your issue:

* version of U-Boot (commit in git)
* operating system and architecture
* installed version of gcc and binutils
* used defconfig
* used commands for building

Best regards

Heinrich

>
> Signed-off-by: Liya Huang <1425075683 at qq.com>
> ---
>
>   examples/api/crt0.S | 10 ++++++----
>   1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/examples/api/crt0.S b/examples/api/crt0.S
> index d2a97557817..d33e1c4aa4d 100644
> --- a/examples/api/crt0.S
> +++ b/examples/api/crt0.S
> @@ -29,15 +29,17 @@ syscall:
>   	.text
>   	.globl _start
>   _start:
> -	ldr	ip, =search_hint
> -	str	sp, [ip]
> +	ldr	r0, =search_hint
> +	mov	r1, sp
> +	str	r1, [r0]
>   	b	main
>
>
>   	.globl syscall
>   syscall:
> -	ldr	ip, =syscall_ptr
> -	ldr	pc, [ip]
> +	ldr	r0, =syscall_ptr
> +	ldr	r0, [r0]
> +	bx	r0
>
>   #elif defined(CONFIG_ARM64)
>