+ ---------------> 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
-----------------------------------------------
$ mkimage -l kernel.itb
FIT description: Simple image with single Linux kernel
Created: Tue Mar 11 17:26:15 2008
- Image 0 (kernel@1)
+ Image 0 (kernel)
Description: Vanilla Linux kernel
Type: Kernel Image
Compression: gzip compressed
Hash value: 2ae2bb40
Hash algo: sha1
Hash value: 3c200f34e2c226ddc789240cca0c59fc54a67cf4
- Default Configuration: 'config@1'
- Configuration 0 (config@1)
+ Default Configuration: 'config-1'
+ Configuration 0 (config-1)
Description: Boot Linux kernel
- Kernel: kernel@1
+ Kernel: kernel
The resulting image file kernel.itb can be now transferred to the target,
FIT image found
FIT description: Simple image with single Linux kernel
Created: 2008-03-11 16:26:15 UTC
- Image 0 (kernel@1)
+ Image 0 (kernel)
Description: Vanilla Linux kernel
Type: Kernel Image
Compression: gzip compressed
Hash value: 2ae2bb40
Hash algo: sha1
Hash value: 3c200f34e2c226ddc789240cca0c59fc54a67cf4
- Default Configuration: 'config@1'
- Configuration 0 (config@1)
+ Default Configuration: 'config-1'
+ Configuration 0 (config-1)
Description: Boot Linux kernel
- Kernel: kernel@1
+ Kernel: kernel
=> bootm
## Booting kernel from FIT Image at 00900000 ...
- Using 'config@1' configuration
- Trying 'kernel@1' kernel subimage
+ Using 'config-1' configuration
+ Trying 'kernel' kernel subimage
Description: Vanilla Linux kernel
Type: Kernel Image
Compression: gzip compressed
$ mkimage -l kernel_fdt.itb
FIT description: Simple image with single Linux kernel and FDT blob
Created: Tue Mar 11 16:29:22 2008
- Image 0 (kernel@1)
+ Image 0 (kernel)
Description: Vanilla Linux kernel
Type: Kernel Image
Compression: gzip compressed
Hash value: 2c0cc807
Hash algo: sha1
Hash value: 264b59935470e42c418744f83935d44cdf59a3bb
- Image 1 (fdt@1)
+ Image 1 (fdt-1)
Description: Flattened Device Tree blob
Type: Flat Device Tree
Compression: uncompressed
Hash value: 0d655d71
Hash algo: sha1
Hash value: 25ab4e15cd4b8a5144610394560d9c318ce52def
- Default Configuration: 'conf@1'
- Configuration 0 (conf@1)
+ Default Configuration: 'conf-1'
+ Configuration 0 (conf-1)
Description: Boot Linux kernel with FDT blob
- Kernel: kernel@1
- FDT: fdt@1
+ Kernel: kernel
+ FDT: fdt-1
The resulting image file kernel_fdt.itb can be now transferred to the target,
FIT image found
FIT description: Simple image with single Linux kernel and FDT blob
Created: 2008-03-11 15:29:22 UTC
- Image 0 (kernel@1)
+ Image 0 (kernel)
Description: Vanilla Linux kernel
Type: Kernel Image
Compression: gzip compressed
Hash value: 2c0cc807
Hash algo: sha1
Hash value: 264b59935470e42c418744f83935d44cdf59a3bb
- Image 1 (fdt@1)
+ Image 1 (fdt-1)
Description: Flattened Device Tree blob
Type: Flat Device Tree
Compression: uncompressed
Hash value: 0d655d71
Hash algo: sha1
Hash value: 25ab4e15cd4b8a5144610394560d9c318ce52def
- Default Configuration: 'conf@1'
- Configuration 0 (conf@1)
+ Default Configuration: 'conf-1'
+ Configuration 0 (conf-1)
Description: Boot Linux kernel with FDT blob
- Kernel: kernel@1
- FDT: fdt@1
+ Kernel: kernel
+ FDT: fdt-1
=> bootm
## Booting kernel from FIT Image at 00900000 ...
- Using 'conf@1' configuration
- Trying 'kernel@1' kernel subimage
+ Using 'conf-1' configuration
+ Trying 'kernel' kernel subimage
Description: Vanilla Linux kernel
Type: Kernel Image
Compression: gzip compressed
Verifying Hash Integrity ... crc32+ sha1+ OK
Uncompressing Kernel Image ... OK
## Flattened Device Tree from FIT Image at 00900000
- Using 'conf@1' configuration
- Trying 'fdt@1' FDT blob subimage
+ Using 'conf-1' configuration
+ Trying 'fdt-1' FDT blob subimage
Description: Flattened Device Tree blob
Type: Flat Device Tree
Compression: uncompressed