diff mbox

[U-Boot,1/1] arm/lib/bootm.c: keep ARM v7M in thumb mode during boot_jump_linux()

Message ID 1493111266-22888-1-git-send-email-patrice.chotard@st.com
State Accepted
Commit dc89c6fb778ed2d12128e2bb976a45d540afce71
Delegated to: Tom Rini
Headers show

Commit Message

Patrice CHOTARD April 25, 2017, 9:07 a.m. UTC 
From: Patrice Chotard <patrice.chotard@st.com>

On ARM v7M, the processor will return to ARM mode when executing
a blx instruction with bit 0 of the address == 0. Always set it
to 1 to stay in thumb mode.

Tested on STM32f746-disco board

Similar commit:
f99993c10882f7dc8ec35993d5febe59aac01e6a
Author: Matt Porter <mporter@konsulko.com>

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
---
 arch/arm/lib/bootm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Tom Rini April 28, 2017, 1:09 p.m. UTC | #1 
On Tue, Apr 25, 2017 at 11:07:46AM +0200, Patrice Chotard wrote:

> From: Patrice Chotard <patrice.chotard@st.com>
> 
> On ARM v7M, the processor will return to ARM mode when executing
> a blx instruction with bit 0 of the address == 0. Always set it
> to 1 to stay in thumb mode.
> 
> Tested on STM32f746-disco board
> 
> Similar commit:
> f99993c10882f7dc8ec35993d5febe59aac01e6a
> Author: Matt Porter <mporter@konsulko.com>
> 
> Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

Applied to u-boot/master, thanks!
diff mbox

Patch

diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 8125cf0..6b1d3ae 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -347,7 +347,10 @@  static void boot_jump_linux(bootm_headers_t *images, int flag)
 	int fake = (flag & BOOTM_STATE_OS_FAKE_GO);
 
 	kernel_entry = (void (*)(int, int, uint))images->ep;
-
+#ifdef CONFIG_CPU_V7M
+	ulong addr = (ulong)kernel_entry | 1;
+	kernel_entry = (void *)addr;
+#endif
 	s = getenv("machid");
 	if (s) {
 		if (strict_strtoul(s, 16, &machid) < 0) {