[U-Boot] [PATCH v2] rockchip: Print a message when returning to the bootrom

[Simon Glass]

At present if the return to bootrom fails (e.g. because you are not using
the Rockchip's bootrom's pointer table in MMC) then the board prints
SPL message and hangs. Print a message first if we can, to help in
understanding what happened when it hangs.

Signed-off-by: Simon Glass <sjg at chromium.org>
Tested-by: Heiko Stuebner <heiko at sntech.de>
Acked-by: Heiko Stuebner <heiko at sntech.de>
---

Changes in v2:
- Make inclusion of bootrom.c conditional in the Makefile
- Update #ifdef check around printf() to include !CONFIG_TPL_BUILD

 arch/arm/include/asm/arch-rockchip/bootrom.h |  9 +++++++--
 arch/arm/mach-rockchip/Makefile              |  2 ++
 arch/arm/mach-rockchip/bootrom.c             | 16 ++++++++++++++++
 arch/arm/mach-rockchip/save_boot_param.S     |  6 +++---
 4 files changed, 28 insertions(+), 5 deletions(-)
 create mode 100644 arch/arm/mach-rockchip/bootrom.c

diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h
index 79fb1a07ac..92eb8783a3 100644
--- a/arch/arm/include/asm/arch-rockchip/bootrom.h
+++ b/arch/arm/include/asm/arch-rockchip/bootrom.h
@@ -13,10 +13,15 @@
  */
 extern u32 SAVE_SP_ADDR;
 
-/*
+/**
  * Hand control back to the bootrom to load another
  * boot stage.
  */
-extern void back_to_bootrom(void);
+void back_to_bootrom(void);
+
+/**
+ * Assembler component for the above (do not call this directly)
+ */
+void _back_to_bootrom_s(void);
 
 #endif
diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index 6b251c7e7e..327b26705d 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -4,6 +4,8 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+obj-$(CONFIG_ROCKCHIP_BROM_HELPER) += bootrom.o
+
 ifdef CONFIG_TPL_BUILD
 obj-$(CONFIG_ROCKCHIP_RK3188) += rk3188-board-tpl.o
 obj-$(CONFIG_ROCKCHIP_BROM_HELPER) += save_boot_param.o
diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c
new file mode 100644
index 0000000000..da36f92697
--- /dev/null
+++ b/arch/arm/mach-rockchip/bootrom.c
@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2017 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arch/bootrom.h>
+
+void back_to_bootrom(void)
+{
+#if defined(CONFIG_SPL_LIBGENERIC_SUPPORT) && !defined(CONFIG_TPL_BUILD)
+	printf("Returning to boot ROM...");
+#endif
+	_back_to_bootrom_s();
+}
diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S
index 85b407b4d3..5e6c8dba13 100644
--- a/arch/arm/mach-rockchip/save_boot_param.S
+++ b/arch/arm/mach-rockchip/save_boot_param.S
@@ -23,10 +23,10 @@ ENTRY(save_boot_params)
 ENDPROC(save_boot_params)
 
 
-.globl back_to_bootrom
-ENTRY(back_to_bootrom)
+.globl _back_to_bootrom_s
+ENTRY(_back_to_bootrom_s)
 	ldr	r0, =SAVE_SP_ADDR
 	ldr	sp, [r0]
 	mov	r0, #0
 	pop	{r1-r12, pc}
-ENDPROC(back_to_bootrom)
+ENDPROC(_back_to_bootrom_s)
-- 
2.12.2.762.g0e3151a226-goog