[PATCH v2 02/14] arm: add initjmp()

[Heinrich Schuchardt]

On 25.02.25 17:34, Jerome Forissier wrote:
> Implement initjmp() for Arm.
>
> Signed-off-by: Jerome Forissier <jerome.forissier at linaro.org>
> ---
>   arch/Kconfig                  |  1 +
>   arch/arm/include/asm/setjmp.h |  1 +
>   arch/arm/lib/setjmp.S         | 11 +++++++++++
>   arch/arm/lib/setjmp_aarch64.S |  9 +++++++++
>   4 files changed, 22 insertions(+)
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index 8d5b54031b3..57695fada8d 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -94,6 +94,7 @@ config ARC
>   config ARM
>   	bool "ARM architecture"
>   	select HAVE_SETJMP
> +	select HAVE_INITJMP
>   	select ARCH_SUPPORTS_LTO
>   	select CREATE_ARCH_SYMLINK
>   	select HAVE_PRIVATE_LIBGCC if !ARM64
> diff --git a/arch/arm/include/asm/setjmp.h b/arch/arm/include/asm/setjmp.h
> index 662bec86321..1ad5b500f2a 100644
> --- a/arch/arm/include/asm/setjmp.h
> +++ b/arch/arm/include/asm/setjmp.h
> @@ -23,5 +23,6 @@ typedef struct jmp_buf_data jmp_buf[1];
>
>   int setjmp(jmp_buf jmp);
>   void longjmp(jmp_buf jmp, int ret);
> +int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);

As this is not a standard function we cannot expect developers to know
what it does and how to use it.

Please, provide Sphinx style documentation with the necessary information.

Best regards

Heinrich

>
>   #endif /* _SETJMP_H_ */
> diff --git a/arch/arm/lib/setjmp.S b/arch/arm/lib/setjmp.S
> index 2f041aeef01..320ddea85f9 100644
> --- a/arch/arm/lib/setjmp.S
> +++ b/arch/arm/lib/setjmp.S
> @@ -34,3 +34,14 @@ ENTRY(longjmp)
>   	ret  lr
>   ENDPROC(longjmp)
>   .popsection
> +
> +.pushsection .text.initjmp, "ax"
> +ENTRY(initjmp)
> +	stm  a1, {v1-v8}
> +	/* a2: entry point address, a3: stack top */
> +	str  a3, [a1, #32]  /* where setjmp would save sp */
> +	str  a2, [a1, #36]  /* where setjmp would save lr */
> +	mov  a1, #0
> +	ret  lr
> +ENDPROC(initjmp)
> +.popsection
> diff --git a/arch/arm/lib/setjmp_aarch64.S b/arch/arm/lib/setjmp_aarch64.S
> index 1b8d000eb48..074320d25fb 100644
> --- a/arch/arm/lib/setjmp_aarch64.S
> +++ b/arch/arm/lib/setjmp_aarch64.S
> @@ -39,3 +39,12 @@ ENTRY(longjmp)
>   	ret
>   ENDPROC(longjmp)
>   .popsection
> +
> +.pushsection .text.initjmp, "ax"
> +ENTRY(initjmp)
> +	/* x1: entry point address, x2: stack top */
> +	stp x1, x2, [x0,#88]
> +	mov  x0, #0
> +	ret
> +ENDPROC(initjmp)
> +.popsection