[U-Boot] [RFC PATCH 1/2] spl: Add an option to load a FIT containing U-Boot from FS

[Lokesh Vutla]

This provides a way to load a FIT containing U-Boot and a selection of device
tree files from a File system.

Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
---
 common/spl/spl_fit.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/spl.h        |  5 +++
 2 files changed, 101 insertions(+)

diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
index 1a5c027..4c9fe7b 100644
--- a/common/spl/spl_fit.c
+++ b/common/spl/spl_fit.c
@@ -192,3 +192,99 @@ int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
 
 	return 0;
 }
+
+int spl_fs_load_simple_fit(struct spl_load_info *info, const char *filename, void *fit)
+{
+	ulong size, load;
+	unsigned long count;
+	int node, images;
+	void *load_ptr;
+	int fdt_offset, fdt_len;
+	int data_offset, data_size, file_offset;
+	int base_offset = 0, align_len;
+	void *dst;
+
+	/*
+	 * Figure out where the external images start. This is the base for the
+	 * data-offset properties in each image.
+	 */
+	size = fdt_totalsize(fit);
+	size = (size + 3) & ~3;
+	base_offset = (size + 3) & ~3;
+
+	/*
+	 * Read the entire FIT header, placing it so it finishes before
+	 * where we will load the image. Also the load address is aligned
+	 * ARCH_DMA_MINALIGN.
+	 */
+	align_len = ARCH_DMA_MINALIGN - 1;
+	fit = (void *)((CONFIG_SYS_TEXT_BASE - size - align_len) & ~align_len);
+	debug("FIT header read: destination = 0x%p, size = %lx \n", fit, size);
+	count = info->fs_read(info, filename, fit, 0, size);
+	if (count <= 0)
+		return -EIO;
+
+	/* find the firmware image to load */
+	images = fdt_path_offset(fit, FIT_IMAGES_PATH);
+	if (images < 0) {
+		printf("%s: Cannot find /images node: %d\n", __func__, images);
+		return -1;
+	}
+	node = fdt_first_subnode(fit, images);
+	if (node < 0) {
+		printf("%s: Cannot find first image node: %d\n", __func__, node);
+		return -1;
+	}
+
+	/* Get its information and set up the spl_image structure */
+	data_offset = fdt_getprop_u32(fit, node, "data-offset");
+	data_size = fdt_getprop_u32(fit, node, "data-size");
+	load = fdt_getprop_u32(fit, node, "load");
+	debug("data_offset=%x, data_size=%x\n", data_offset, data_size);
+	spl_image.load_addr = load;
+	spl_image.entry_point = load;
+	spl_image.os = IH_OS_U_BOOT;
+
+	/*
+	 * Work out where to place the image. Assuming load addr of u-boot.bin
+	 * is always aligned to ARCH_DMA_MINALIGN. It is possible that file
+	 * offset is not aligned. In order to make sure that the file read is
+	 * dma aligned, align the file offset to dma with extra bytes in the
+	 * beginning. Then do a memcpy of image to dst.
+	 */
+	data_offset += base_offset;
+	file_offset = data_offset & ~align_len;
+	load_ptr = (void *)load;
+	dst = load_ptr;
+
+	/* Read the image */
+	debug("Temp u-boot.bin read from fit: dst = 0x%p, file offset = 0x%x, size = 0x%x\n",
+	      dst, file_offset, data_size);
+	count = info->fs_read(info, filename, dst, file_offset, data_size);
+	if (count <= 0)
+		return -EIO;
+	debug("u-boot.bin load: dst = 0x%p, size = 0x%x\n", dst, data_size);
+	memcpy(dst, dst + (data_offset & align_len), data_size);
+
+	/* Figure out which device tree the board wants to use */
+	fdt_len = spl_fit_select_fdt(fit, images, &fdt_offset);
+	if (fdt_len < 0)
+		return fdt_len;
+
+	/*
+	 * Read the device tree and place it after the image. Making sure that
+	 * load addr and file offset are aligned to dma.
+	 */
+	dst = (void *)((load + data_size + align_len) & ~align_len);
+	fdt_offset += base_offset;
+	file_offset = fdt_offset & ~align_len;
+	debug("Temp fdt read from fit: dst = 0x%p, file offset = 0x%x, size = %d\n",
+	      dst, file_offset, data_size);
+	count = info->fs_read(info, filename, dst, file_offset, data_size);
+	if (count <= 0)
+		return -EIO;
+	debug("fdt load: dst = 0x%p, size = 0x%x\n", load_ptr + data_size, data_size);
+	memcpy(load_ptr + data_size, dst + (fdt_offset & align_len), data_size);
+
+	return 1;
+}
diff --git a/include/spl.h b/include/spl.h
index de4f70a..276ca12 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -36,6 +36,7 @@ struct spl_image_info {
  * @priv: Private data for the device
  * @bl_len: Block length for reading in bytes
  * @read: Function to call to read from the device
+ * @fd_read: Function to call to read from the a fs
  */
 struct spl_load_info {
 	void *dev;
@@ -43,9 +44,13 @@ struct spl_load_info {
 	int bl_len;
 	ulong (*read)(struct spl_load_info *load, ulong sector, ulong count,
 		      void *buf);
+	int (*fs_read)(struct spl_load_info *load, const char *filename,
+		      void *buf, ulong file_offset, ulong size);
 };
 
 int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fdt);
+int spl_fs_load_simple_fit(struct spl_load_info *info, const char *filename,
+			   void *fit);
 
 #define SPL_COPY_PAYLOAD_ONLY	1
 
-- 
2.1.4