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From: nicolas.pitre@linaro.org (Nicolas Pitre)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/3] ARM: semihosting: use proper instruction on v7m processors
Date: Sun,  1 Oct 2017 22:06:17 -0400	[thread overview]
Message-ID: <20171002020618.23924-3-nicolas.pitre@linaro.org> (raw)
In-Reply-To: <20171002020618.23924-1-nicolas.pitre@linaro.org>

The svc instruction doesn't exist on v7m processors. Semihosting ops are
invoked with the bkpt instruction instead.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
 arch/arm/boot/compressed/debug.S | 4 ++++
 arch/arm/kernel/debug.S          | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/arm/boot/compressed/debug.S b/arch/arm/boot/compressed/debug.S
index 5392ee6333..8f6e37177d 100644
--- a/arch/arm/boot/compressed/debug.S
+++ b/arch/arm/boot/compressed/debug.S
@@ -23,7 +23,11 @@ ENTRY(putc)
 	strb	r0, [r1]
 	mov	r0, #0x03		@ SYS_WRITEC
    ARM(	svc	#0x123456	)
+#ifdef CONFIG_CPU_V7M
+ THUMB(	bkpt	#0xab		)
+#else
  THUMB(	svc	#0xab		)
+#endif
 	mov	pc, lr
 	.align	2
 1:	.word	_GLOBAL_OFFSET_TABLE_ - .
diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S
index 423f443258..35145b618c 100644
--- a/arch/arm/kernel/debug.S
+++ b/arch/arm/kernel/debug.S
@@ -121,7 +121,11 @@ ENTRY(printascii)
 		mov	r1, r0
 		mov	r0, #0x04		@ SYS_WRITE0
 	ARM(	svc	#0x123456	)
+#ifdef CONFIG_CPU_V7M
+	THUMB(	bkpt	#0xab		)
+#else
 	THUMB(	svc	#0xab		)
+#endif
 		ret	lr
 ENDPROC(printascii)
 
@@ -132,7 +136,11 @@ ENTRY(printch)
 		strb	r0, [r1]
 		mov	r0, #0x03		@ SYS_WRITEC
 	ARM(	svc	#0x123456	)
+#ifdef CONFIG_CPU_V7M
+	THUMB(	bkpt	#0xab		)
+#else
 	THUMB(	svc	#0xab		)
+#endif
 		ret	lr
 ENDPROC(printch)
 
-- 
2.9.5

  parent reply	other threads:[~2017-10-02  2:06 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-02  2:06 [PATCH 0/3] a few debug_ll fixes and improvements Nicolas Pitre
2017-10-02  2:06 ` [PATCH 1/3] ARM: debug.S: move hexbuf to a writable section Nicolas Pitre
2017-10-02  2:06 ` Nicolas Pitre [this message]
2017-10-02  2:06 ` [PATCH 3/3] ARM: early_printk: use printascii() rather than printch() Nicolas Pitre
2017-10-02  5:20   ` Uwe Kleine-König
2017-10-02 14:09     ` Nicolas Pitre
2017-10-31 11:28   ` Chris Brandt
2017-10-31 16:22     ` Nicolas Pitre
2017-10-31 16:38       ` Robin Murphy
2017-10-31 17:06         ` Nicolas Pitre
2017-10-31 17:16           ` Russell King - ARM Linux
2017-10-31 17:48             ` Nicolas Pitre
2017-10-31 17:53               ` Russell King - ARM Linux
2017-10-31 18:15                 ` Nicolas Pitre
2017-10-31 18:20                   ` Russell King - ARM Linux
2017-10-31 18:35                     ` Nicolas Pitre
2017-10-31 19:12                       ` Chris Brandt
2017-10-31 19:28                         ` Nicolas Pitre
2017-10-31 21:50                           ` Russell King - ARM Linux
2017-10-31 23:35                             ` Nicolas Pitre
2017-10-31 23:50                               ` Russell King - ARM Linux
2017-11-02  0:09                         ` Russell King - ARM Linux
2017-11-02  3:59                           ` Nicolas Pitre
2017-11-02  4:16                             ` Nicolas Pitre
2017-11-02 11:09                               ` Russell King - ARM Linux
2017-11-02 15:12                                 ` Nicolas Pitre
2017-11-02 11:06                             ` Chris Brandt
2017-11-02 11:20                               ` Russell King - ARM Linux
2017-11-02 11:28                                 ` Chris Brandt
2017-11-02 13:04                                   ` Russell King - ARM Linux
2017-11-02 15:04                                   ` Nicolas Pitre
2017-11-02 15:18                                     ` Robin Murphy
2017-11-02 15:22                                       ` Russell King - ARM Linux
2017-11-02 15:25                                       ` Chris Brandt
2017-11-02 15:23                                     ` Chris Brandt
2017-11-02 15:35                                       ` Nicolas Pitre
2017-11-02 16:06                                         ` Nicolas Pitre
2017-11-02 16:38                                           ` Chris Brandt
2017-11-02 17:10                                             ` Russell King - ARM Linux
2017-11-02 17:20                                               ` Nicolas Pitre
2017-11-02 17:28                                               ` Chris Brandt
2017-11-02 18:29                                               ` Robin Murphy
2017-11-02 21:46                                                 ` syntax unified, was " Nicolas Pitre
2017-11-02 15:48                                       ` Russell King - ARM Linux
2017-11-02 16:30                                         ` Chris Brandt

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