[U-Boot] [PATCH v2 1/2] arm: add support for semihosting for ARMv7M targets

[Vadzim Dambrouski]

It is possible to enable CONFIG_SEMIHOSTING for STM32F429 target, but it
would result in compile error. This patch adds support for semihosting for
STM32F429 or any other ARMv7M target. Tested on STM32F429-DISCOVERY board.

Signed-off-by: Vadzim Dambrouski <pftbest at gmail.com>
---

 arch/arm/lib/semihosting.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/lib/semihosting.c b/arch/arm/lib/semihosting.c
index c3e964e..ed5e8e4 100644
--- a/arch/arm/lib/semihosting.c
+++ b/arch/arm/lib/semihosting.c
@@ -31,6 +31,8 @@ static noinline long smh_trap(unsigned int sysnum, void *addr)
 	register long result asm("r0");
 #if defined(CONFIG_ARM64)
 	asm volatile ("hlt #0xf000" : "=r" (result) : "0"(sysnum), "r"(addr));
+#elif defined(CONFIG_CPU_V7M)
+	asm volatile ("bkpt #0xAB" : "=r" (result) : "0"(sysnum), "r"(addr));
 #else
 	/* Note - untested placeholder */
 	asm volatile ("svc #0x123456" : "=r" (result) : "0"(sysnum), "r"(addr));
-- 
2.6.1