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-rw-r--r--doc/uImage.FIT/howto.txt21
-rw-r--r--doc/uImage.FIT/multi_spl.its89
2 files changed, 110 insertions, 0 deletions
diff --git a/doc/uImage.FIT/howto.txt b/doc/uImage.FIT/howto.txt
index 14e316f..2988a52 100644
--- a/doc/uImage.FIT/howto.txt
+++ b/doc/uImage.FIT/howto.txt
@@ -44,6 +44,27 @@ image source file mkimage + dtc transfer to target
+ ---------------> image file --------------------> bootm
image data file(s)
+SPL usage
+---------
+
+The SPL can make use of the new image format as well, this traditionally
+is used to ship multiple device tree files within one image. Code in the SPL
+will choose the one matching the current board and append this to the
+U-Boot proper binary to be automatically used up by it.
+Aside from U-Boot proper and one device tree blob the SPL can load multiple,
+arbitrary image files as well. These binaries should be specified in their
+own subnode under the /images node, which should then be referenced from one or
+multiple /configurations subnodes. The required images must be enumerated in
+the "loadables" property as a list of strings.
+
+If a platform specific image source file (.its) is shipped with the U-Boot
+source, it can be specified using the CONFIG_SPL_FIT_SOURCE Kconfig symbol.
+In this case it will be automatically used by U-Boot's Makefile to generate
+the image.
+If a static source file is not flexible enough, CONFIG_SPL_FIT_GENERATOR
+can point to a script which generates this image source file during
+the build process. It gets passed a list of device tree files (taken from the
+CONFIG_OF_LIST symbol).
Example 1 -- old-style (non-FDT) kernel booting
-----------------------------------------------
diff --git a/doc/uImage.FIT/multi_spl.its b/doc/uImage.FIT/multi_spl.its
new file mode 100644
index 0000000..e5551d4
--- /dev/null
+++ b/doc/uImage.FIT/multi_spl.its
@@ -0,0 +1,89 @@
+/dts-v1/;
+
+/*
+ * (Bogus) example FIT image description file demonstrating the usage
+ * of multiple images loaded by the SPL.
+ * Several binaries will be loaded at their respective load addresses.
+ * Finally the one image specifying an entry point will be entered by the SPL.
+ */
+
+/ {
+ description = "multiple firmware blobs and U-Boot, loaded by SPL";
+ #address-cells = <0x1>;
+
+ images {
+
+ uboot {
+ description = "U-Boot (64-bit)";
+ type = "standalone";
+ arch = "arm64";
+ compression = "none";
+ load = <0x4a000000>;
+ };
+
+ atf {
+ description = "ARM Trusted Firmware";
+ type = "firmware";
+ arch = "arm64";
+ compression = "none";
+ load = <0x18000>;
+ entry = <0x18000>;
+ };
+
+ mgmt-firmware {
+ description = "arisc management processor firmware";
+ type = "firmware";
+ arch = "or1k";
+ compression = "none";
+ load = <0x40000>;
+ };
+
+ fdt@1 {
+ description = "Pine64+ DT";
+ type = "flat_dt";
+ compression = "none";
+ load = <0x4fa00000>;
+ arch = "arm64";
+ };
+
+ fdt@2 {
+ description = "Pine64 DT";
+ type = "flat_dt";
+ compression = "none";
+ load = <0x4fa00000>;
+ arch = "arm64";
+ };
+
+ kernel {
+ description = "4.7-rc5 kernel";
+ type = "kernel";
+ compression = "none";
+ load = <0x40080000>;
+ arch = "arm64";
+ };
+
+ initrd {
+ description = "Debian installer initrd";
+ type = "ramdisk";
+ compression = "none";
+ load = <0x4fe00000>;
+ arch = "arm64";
+ };
+ };
+
+ configurations {
+ default = "config@1";
+
+ config@1 {
+ description = "sun50i-a64-pine64-plus";
+ loadables = "uboot", "atf", "kernel", "initrd";
+ fdt = "fdt@1";
+ };
+
+ config@2 {
+ description = "sun50i-a64-pine64";
+ loadables = "uboot", "atf", "mgmt-firmware";
+ fdt = "fdt@2";
+ };
+ };
+};