[U-Boot] [PATCH 3/6] SPL: Add XIP booting support

[Vikas Manocha]

Enable support for XIP (execute in place) of U-Boot or kernel image. There is
no need to copy image from flash to ram if flash supports execute in place.

Signed-off-by: Vikas Manocha <vikas.manocha at st.com>
---
 arch/arm/include/asm/spl.h                 |  1 +
 board/st/stm32f746-disco/stm32f746-disco.c |  1 +
 common/spl/Kconfig                         |  9 +++++++++
 common/spl/Makefile                        |  1 +
 common/spl/spl_xip.c                       | 31 ++++++++++++++++++++++++++++++
 5 files changed, 43 insertions(+)
 create mode 100644 common/spl/spl_xip.c

diff --git a/arch/arm/include/asm/spl.h b/arch/arm/include/asm/spl.h
index a0bda28..0a3536b 100644
--- a/arch/arm/include/asm/spl.h
+++ b/arch/arm/include/asm/spl.h
@@ -29,6 +29,7 @@ enum {
 	BOOT_DEVICE_I2C,
 	BOOT_DEVICE_BOARD,
 	BOOT_DEVICE_DFU,
+	BOOT_DEVICE_XIP,
 	BOOT_DEVICE_NONE
 };
 #endif
diff --git a/board/st/stm32f746-disco/stm32f746-disco.c b/board/st/stm32f746-disco/stm32f746-disco.c
index 4f2b677..e330b1f 100644
--- a/board/st/stm32f746-disco/stm32f746-disco.c
+++ b/board/st/stm32f746-disco/stm32f746-disco.c
@@ -91,6 +91,7 @@ int board_early_init_f(void)
 #endif
 
 #ifdef CONFIG_SPL_BUILD
+
 int spl_dram_init(void)
 {
 	struct udevice *dev;
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index f51ae2c..52a5271 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -459,6 +459,15 @@ config SPL_NOR_SUPPORT
 	  a memory-mapped device makes it very easy to access. Loading from
 	  NOR is typically achieved with just a memcpy().
 
+config SPL_XIP_SUPPORT
+	bool "Support XIP"
+	depends on SPL
+	help
+	  Enable support for execute in place of U-Boot or kernel image. There
+	  is no need to copy image from flash to ram if flash supports execute
+	  in place. Its very useful in systems having enough flash but not
+	  enough ram to load the image.
+
 config SPL_ONENAND_SUPPORT
 	bool "Support OneNAND flash"
 	depends on SPL
diff --git a/common/spl/Makefile b/common/spl/Makefile
index 1933cbd..88deeaf 100644
--- a/common/spl/Makefile
+++ b/common/spl/Makefile
@@ -12,6 +12,7 @@ ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_SPL_FRAMEWORK) += spl.o
 obj-$(CONFIG_SPL_LOAD_FIT) += spl_fit.o
 obj-$(CONFIG_SPL_NOR_SUPPORT) += spl_nor.o
+obj-$(CONFIG_SPL_XIP_SUPPORT) += spl_xip.o
 obj-$(CONFIG_SPL_YMODEM_SUPPORT) += spl_ymodem.o
 ifndef CONFIG_SPL_UBI
 obj-$(CONFIG_SPL_NAND_SUPPORT) += spl_nand.o
diff --git a/common/spl/spl_xip.c b/common/spl/spl_xip.c
new file mode 100644
index 0000000..50e2f34
--- /dev/null
+++ b/common/spl/spl_xip.c
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2017 Vikas Manocha <vikas.manocha at st.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <spl.h>
+
+static int spl_xip(struct spl_image_info *spl_image,
+		   struct spl_boot_device *bootdev)
+{
+#ifdef CONFIG_SPL_OS_BOOT
+	if (!spl_start_uboot()) {
+		spl_image->arg = (void *)CONFIG_SYS_FDT_BASE;
+		spl_image->name = "Linux";
+		spl_image->os = IH_OS_LINUX;
+		spl_image->load_addr = CONFIG_SYS_LOAD_ADDR;
+		spl_image->entry_point = CONFIG_SYS_LOAD_ADDR;
+#ifdef CONFIG_CPU_V7M
+		spl_image->entry_point |= 0x1;
+#endif
+		debug("spl: payload xipImage, load addr: 0x%lx\n",
+		      spl_image->load_addr);
+		return 0;
+	}
+#endif
+	return(spl_parse_image_header(spl_image, (const struct image_header *)
+	       CONFIG_SYS_UBOOT_BASE));
+}
+SPL_LOAD_IMAGE_METHOD("XIP", 0, BOOT_DEVICE_XIP, spl_xip);
-- 
1.9.1