[U-Boot] [PATCH v3 1/2] arm: add support for semihosting for ARMv7M targets

Albert ARIBAUD albert.u.boot at aribaud.net
Thu Oct 22 12:42:35 CEST 2015


Hello Vadzim,

On Mon, 19 Oct 2015 19:40:14 +0300, Vadzim Dambrouski
<pftbest at gmail.com> wrote:
> If you enable CONFIG_SEMIHOSTING for STM32F429 target, you will get compile
> error looking like this:
> 
> arch/arm/lib/semihosting.c: In function 'smh_read':
> {standard input}: Assembler messages:
> {standard input}:34: Error: invalid swi expression
> {standard input}:34: Error: value of 1193046 too large for field of 2 bytes at 0
> scripts/Makefile.build:277: recipe for target 'arch/arm/lib/semihosting.o' failed
> 
> The source of the problem is "svc #0x123456" instruction. This instruction
> can not be encoded using Thumb2 instruction set used by ARMv7M CPUs.
> ARM documentation suggests using "bkpt #0xAB" instruction instead [1].
> This patch fixes compile errors and adds support for semihosting for
> STM32F429 or any other ARMv7M target.
> This change was sested on STM32F429-DISCOVERY board using OpenOCD and
> "smhload" u-boot command.
> 
> [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0471c/Bgbjhiea.html
> 
> Signed-off-by: Vadzim Dambrouski <pftbest at gmail.com>
> ---

Can someone provide their 'Tested-by' on this?

Amicalement,
-- 
Albert.


More information about the U-Boot mailing list