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    432a6241
    arm: add support for semihosting for ARMv7M targets · 432a6241
    Vadzim Dambrouski authored
    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: default avatarVadzim Dambrouski <pftbest@gmail.com>
    432a6241
    History
    arm: add support for semihosting for ARMv7M targets
    Vadzim Dambrouski authored
    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: default avatarVadzim Dambrouski <pftbest@gmail.com>