spl: Add an option to load a FIT containing U-Boot

This provides a way to load a FIT containing U-Boot and a selection of device
tree files. The board can select the correct device tree by probing the
hardware. Then U-Boot is started with the selected device tree.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/Kconfig b/Kconfig
index a9a4938..e7002ed 100644 (file)
--- a/Kconfig
+++ b/Kconfig
@@ -273,6 +273,17 @@ config SYS_TEXT_BASE
        help
          TODO: Move CONFIG_SYS_TEXT_BASE for all the architecture
 
+config SPL_LOAD_FIT
+       bool "Enable SPL loading U-Boot as a FIT"
+       depends on FIT
+       help
+         Normally with the SPL framework a legacy image is generated as part
+         of the build. This contains U-Boot along with information as to
+         where it should be loaded. This option instead enables generation
+         of a FIT (Flat Image Tree) which provides more flexibility. In
+         particular it can handle selecting from multiple device tree
+         and passing the correct one to U-Boot.
+
 config SYS_CLK_FREQ
        depends on ARC || ARCH_SUNXI
        int "CPU clock frequency"

diff --git a/common/spl/Makefile b/common/spl/Makefile
index 10a4589..2e0f695 100644 (file)
--- a/common/spl/Makefile
+++ b/common/spl/Makefile
@@ -10,6 +10,7 @@
 
 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_YMODEM_SUPPORT) += spl_ymodem.o
 obj-$(CONFIG_SPL_NAND_SUPPORT) += spl_nand.o

diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
new file mode 100644 (file)
index 0000000..1a5c027
--- /dev/null
+++ b/common/spl/spl_fit.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2016 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <image.h>
+#include <libfdt.h>
+#include <spl.h>
+
+static ulong fdt_getprop_u32(const void *fdt, int node, const char *prop)
+{
+       const u32 *cell;
+       int len;
+
+       cell = fdt_getprop(fdt, node, prop, &len);
+       if (len != sizeof(*cell))
+               return -1U;
+       return fdt32_to_cpu(*cell);
+}
+
+static int spl_fit_select_fdt(const void *fdt, int images, int *fdt_offsetp)
+{
+       const char *name, *fdt_name;
+       int conf, node, fdt_node;
+       int len;
+
+       *fdt_offsetp = 0;
+       conf = fdt_path_offset(fdt, FIT_CONFS_PATH);
+       if (conf < 0) {
+               debug("%s: Cannot find /configurations node: %d\n", __func__,
+                     conf);
+               return -EINVAL;
+       }
+       for (node = fdt_first_subnode(fdt, conf);
+            node >= 0;
+            node = fdt_next_subnode(fdt, node)) {
+               name = fdt_getprop(fdt, node, "description", &len);
+               if (!name)
+                       return -EINVAL;
+               if (board_fit_config_name_match(name))
+                       continue;
+
+               debug("Selecting config '%s'", name);
+               fdt_name = fdt_getprop(fdt, node, FIT_FDT_PROP, &len);
+               if (!fdt_name) {
+                       debug("%s: Cannot find fdt name property: %d\n",
+                             __func__, len);
+                       return -EINVAL;
+               }
+
+               debug(", fdt '%s'\n", fdt_name);
+               fdt_node = fdt_subnode_offset(fdt, images, fdt_name);
+               if (fdt_node < 0) {
+                       debug("%s: Cannot find fdt node '%s': %d\n",
+                             __func__, fdt_name, fdt_node);
+                       return -EINVAL;
+               }
+
+               *fdt_offsetp = fdt_getprop_u32(fdt, fdt_node, "data-offset");
+               len = fdt_getprop_u32(fdt, fdt_node, "data-size");
+#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
+               printf("FIT: Selected '%s'\n", name);
+#endif
+
+               return len;
+       }
+
+#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
+       printf("No matching DT out of these options:\n");
+       for (node = fdt_first_subnode(fdt, conf);
+            node >= 0;
+            node = fdt_next_subnode(fdt, node)) {
+               name = fdt_getprop(fdt, node, "name", &len);
+               printf("   %s\n", name);
+       }
+#endif
+
+       return -ENOENT;
+}
+
+int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fit)
+{
+       int sectors;
+       ulong size, load;
+       unsigned long count;
+       int node, images;
+       void *load_ptr;
+       int fdt_offset, fdt_len;
+       int data_offset, data_size;
+       int base_offset;
+       int src_sector;
+       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;
+
+       /*
+        * So far we only have one block of data from the FIT. Read the entire
+        * thing, including that first block, placing it so it finishes before
+        * where we will load the image.
+        *
+        * Note that we will load the image such that its first byte will be
+        * at the load address. Since that byte may be part-way through a
+        * block, we may load the image up to one block before the load
+        * address. So take account of that here by subtracting an addition
+        * block length from the FIT start position.
+        *
+        * In fact the FIT has its own load address, but we assume it cannot
+        * be before CONFIG_SYS_TEXT_BASE.
+        */
+       fit = (void *)(CONFIG_SYS_TEXT_BASE - size - info->bl_len);
+       sectors = (size + info->bl_len - 1) / info->bl_len;
+       count = info->read(info, sector, sectors, fit);
+       debug("fit read sector %lx, sectors=%d, dst=%p, count=%lu\n",
+             sector, sectors, fit, count);
+       if (count == 0)
+               return -EIO;
+
+       /* find the firmware image to load */
+       images = fdt_path_offset(fit, FIT_IMAGES_PATH);
+       if (images < 0) {
+               debug("%s: Cannot find /images node: %d\n", __func__, images);
+               return -1;
+       }
+       node = fdt_first_subnode(fit, images);
+       if (node < 0) {
+               debug("%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. We read it so that the first
+        * byte will be at 'load'. This may mean we need to load it starting
+        * before then, since we can only read whole blocks.
+        */
+       sectors = (data_size + info->bl_len - 1) / info->bl_len;
+       data_offset += base_offset;
+       load_ptr = (void *)load;
+       debug("U-Boot size %x, data %p\n", data_size, load_ptr);
+       dst = load_ptr - (data_offset % info->bl_len);
+
+       /* Read the image */
+       src_sector = sector + data_offset / info->bl_len;
+       debug("image: data_offset=%x, dst=%p, src_sector=%x, sectors=%x\n",
+             data_offset, dst, src_sector, sectors);
+       count = info->read(info, src_sector, sectors, dst);
+       if (count != sectors)
+               return -EIO;
+
+       /* 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. There may be
+        * some extra data before it since we can only read entire blocks.
+        */
+       dst = load_ptr + data_size;
+       fdt_offset += base_offset;
+       count = info->read(info, sector + fdt_offset / info->bl_len, sectors,
+                          dst);
+       debug("fit read %x sectors to %x, dst %p, data_offset %x\n",
+             sectors, spl_image.load_addr, dst, fdt_offset);
+       if (count != sectors)
+               return -EIO;
+
+       /*
+        * Copy the device tree so that it starts immediately after the image.
+        * After this we will have the U-Boot image and its device tree ready
+        * for us to start.
+        */
+       memcpy(dst, dst + fdt_offset % info->bl_len, fdt_len);
+
+       return 0;
+}

diff --git a/include/image.h b/include/image.h
index 0605280..f9ee564 100644 (file)
--- a/include/image.h
+++ b/include/image.h
@@ -780,7 +780,6 @@ int bootz_setup(ulong image, ulong *start, ulong *end);
 /*******************************************************************/
 /* New uImage format specific code (prefixed with fit_) */
 /*******************************************************************/
-#if IMAGE_ENABLE_FIT
 
 #define FIT_IMAGES_PATH                "/images"
 #define FIT_CONFS_PATH         "/configurations"
@@ -813,6 +812,7 @@ int bootz_setup(ulong image, ulong *start, ulong *end);
 
 #define FIT_MAX_HASH_LEN       HASH_MAX_DIGEST_SIZE
 
+#if IMAGE_ENABLE_FIT
 /* cmdline argument format parsing */
 int fit_parse_conf(const char *spec, ulong addr_curr,
                ulong *addr, const char **conf_name);

diff --git a/include/spl.h b/include/spl.h
index 92cdc04..16f2f6a 100644 (file)
--- a/include/spl.h
+++ b/include/spl.h
@@ -29,6 +29,24 @@ struct spl_image_info {
        u32 flags;
 };
 
+/*
+ * Information required to load data from a device
+ *
+ * @dev: Pointer to the device, e.g. struct mmc *
+ * @priv: Private data for the device
+ * @bl_len: Block length for reading in bytes
+ * @read: Function to call to read from the device
+ */
+struct spl_load_info {
+       void *dev;
+       void *priv;
+       int bl_len;
+       ulong (*read)(struct spl_load_info *load, ulong sector, ulong count,
+                     void *buf);
+};
+
+int spl_load_simple_fit(struct spl_load_info *info, ulong sector, void *fdt);
+
 #define SPL_COPY_PAYLOAD_ONLY  1
 
 extern struct spl_image_info spl_image;