[U-Boot] [PATCH v2 1/7] spl: armv7m: to keep ARM v7M in thumb mode before booting next image

Vikas Manocha vikas.manocha at st.com
Sun May 28 19:55:08 UTC 2017


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

At present, it is applied only for raw U-Boot. This patch moves it to just
before booting next image. This way armv7m will be in thumb mode for any image
like raw or image with header like zImage or standard U-Boot.

Signed-off-by: Vikas Manocha <vikas.manocha at st.com>
---

Changed in v2: Added this patch in v2

 common/spl/spl.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/common/spl/spl.c b/common/spl/spl.c
index df984b8..1bdae3e 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -121,9 +121,6 @@ void spl_set_header_raw_uboot(struct spl_image_info *spl_image)
 {
 	spl_image->size = CONFIG_SYS_MONITOR_LEN;
 	spl_image->entry_point = CONFIG_SYS_UBOOT_START;
-#ifdef CONFIG_CPU_V7M
-	spl_image->entry_point |= 0x1;
-#endif
 	spl_image->load_addr = CONFIG_SYS_TEXT_BASE;
 	spl_image->os = IH_OS_U_BOOT;
 	spl_image->name = "U-Boot";
@@ -396,6 +393,9 @@ void board_init_r(gd_t *dummy1, ulong dummy2)
 		hang();
 	}
 
+#ifdef CONFIG_CPU_V7M
+	spl_image.entry_point |= 0x1;
+#endif
 	switch (spl_image.os) {
 	case IH_OS_U_BOOT:
 		debug("Jumping to U-Boot\n");
-- 
1.9.1



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