[new uImage] Add new uImage format documentation and examples

Create doc/uImage.FIT documentation directory with the following files:
- command_syntax_extensions.txt : extended command syntax description
- howto.txt                     : short usage howto
- source_file_format.txt        : internal new uImage format description

Add example image source files:
- kernel.its
- kernel_fdt.its
- multi.its

Update README appropriately.

Signed-off-by: Marian Balakowicz <m8@semihalf.com>
Signed-off-by: Bartlomiej Sieka <tur@semihalf.com>

README

@@ -2684,6 +2684,14 @@ Some configuration options can be set using Environment Variables:
 		  configuration from the BOOTP server, but not try to
 		  load any image using TFTP
 
+  autoscript	- if set to "yes" commands like "loadb", "loady",
+		  "bootp", "tftpb", "rarpboot" and "nfs" will attempt
+		  to automatically run script images (by internally
+		  calling "autoscript").
+
+  autoscript_uname - if script image is in a format (FIT) this
+		     variable is used to get script subimage unit name.
+
   autostart	- if set to "yes", an image loaded using the "bootp",
 		  "rarpboot", "tftpboot" or "diskboot" commands will
 		  be automatically started (by internally calling
@@ -2898,10 +2906,24 @@ o If neither SROM nor the environment contain a MAC address, an error
 Image Formats:
 ==============
 
-The "boot" commands of this monitor operate on "image" files which
-can be basicly anything, preceeded by a special header; see the
-definitions in include/image.h for details; basicly, the header
-defines the following image properties:
+U-Boot is capable of booting (and performing other auxiliary operations on)
+images in two formats:
+
+New uImage format (FIT)
+-----------------------
+
+Flexible and powerful format based on Flattened Image Tree -- FIT (similar
+to Flattened Device Tree). It allows the use of images with multiple
+components (several kernels, ramdisks, etc.), with contents protected by
+SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
+
+
+Old uImage format
+-----------------
+
+Old image format is based on binary files which can be basically anything,
+preceded by a special header; see the definitions in include/image.h for
+details; basically, the header defines the following image properties:
 
 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
   4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,

doc/uImage.FIT/command_syntax_extensions.txt

@@ -0,0 +1,191 @@
+Command syntax extensions for the new uImage format
+===================================================
+
+Author: Bartlomiej Sieka <tur@semihalf.com>
+
+With the introduction of the new uImage format, bootm command (and other
+commands as well) have to understand new syntax of the arguments. This is
+necessary in order to specify objects contained in the new uImage, on which
+bootm has to operate. This note attempts to first summarize bootm usage
+scenarios, and then introduces new argument syntax.
+
+
+bootm usage scenarios
+---------------------
+
+Below is a summary of bootm usage scenarios, focused on booting a PowerPC
+Linux kernel. The purpose of the following list is to document a complete list
+of supported bootm usages.
+
+Note: U-Boot supports two methods of booting a PowerPC Linux kernel: old way,
+i.e., without passing the Flattened Device Tree (FDT), and new way, where the
+kernel is passed a pointer to the FDT. The boot method is indicated for each
+scenario.
+
+
+1.  bootm               boot image at the current address, equivalent to 2,3,8
+
+Old uImage:
+2.  bootm <addr1>                   /* single image at <addr1> */
+3.  bootm <addr1>                   /* multi-image at <addr1>  */
+4.  bootm <addr1> -                 /* multi-image at <addr1>  */
+5.  bootm <addr1> <addr2>           /* single image at <addr1> */
+6.  bootm <addr1> <addr2> <addr3>   /* single image at <addr1> */
+7.  bootm <addr1> -       <addr3>   /* single image at <addr1> */
+
+New uImage:
+8.  bootm <addr1>
+9.  bootm [<addr1>]:<subimg1>
+10. bootm [<addr1>]#<conf>
+11. bootm [<addr1>]:<subimg1> [<addr2>]:<subimg2>
+12. bootm [<addr1>]:<subimg1> [<addr2>]:<subimg2> [<addr3>]:<subimg3>
+13. bootm [<addr1>]:<subimg1> [<addr2>]:<subimg2> <addr3>
+14. bootm [<addr1>]:<subimg1> -                   [<addr3>]:<subimg3>
+15. bootm [<addr1>]:<subimg1> -                   <addr3>
+
+
+Ad. 1. This is equivalent to cases 2,3,8, depending on the type of image at
+the current image address.
+- boot method: see cases 2,3,8
+
+Ad. 2. Boot kernel image located at <addr1>.
+- boot method: non-FDT
+
+Ad. 3. First and second components of the image at <addr1> are assumed to be a
+kernel and a ramdisk, respectively. The kernel is booted with initrd loaded
+with the ramdisk from the image.
+- boot method: depends on the number of components at <addr1>, and on whether
+  U-Boot is compiled with OF support:
+
+                    |          2 components |          3 components |
+                    |      (kernel, initrd) | (kernel, initrd, fdt) |
+---------------------------------------------------------------------
+#ifdef CONFIG_OF_*  |               non-FDT |                   FDT |
+#ifndef CONFIG_OF_* |               non-FDT |               non-FDT |
+
+Ad. 4. Similar to case 3, but the kernel is booted without initrd.  Second
+component of the multi-image is irrelevant (it can be a dummy, 1-byte file).
+- boot method: see case 3
+
+Ad. 5. Boot kernel image located at <addr1> with initrd loaded with ramdisk
+from the image at <addr2>.
+- boot method: non-FDT
+
+Ad. 6. <addr1> is the address of a kernel image, <addr2> is the address of a
+ramdisk image, and <addr3> is the address of a FDT binary blob.  Kernel is
+booted with initrd loaded with ramdisk from the image at <addr2>.
+- boot method: FDT
+
+Ad. 7. <addr1> is the address of a kernel image and <addr3> is the address of
+a FDT binary blob. Kernel is booted without initrd.
+- boot method: FDT
+
+Ad. 8. Image at <addr1> is assumed to contain a default configuration, which
+is booted.
+- boot method: FDT or non-FDT, depending on whether the default configuration
+  defines FDT
+
+Ad. 9. Similar to case 2: boot kernel stored in <subimg1> from the image at
+address <addr1>.
+- boot method: non-FDT
+
+Ad. 10. Boot configuration <conf> from the image at <addr1>.
+- boot method: FDT or non-FDT, depending on whether the configuration given
+  defines FDT
+
+Ad. 11. Equivalent to case 5: boot kernel stored in <subimg1> from the image
+at <addr1> with initrd loaded with ramdisk <subimg2> from the image at
+<addr2>.
+- boot method: non-FDT
+
+Ad. 12. Equivalent to case 6: boot kernel stored in <subimg1> from the image
+at <addr1> with initrd loaded with ramdisk <subimg2> from the image at
+<addr2>, and pass FDT blob <subimg3> from the image at <addr3>.
+- boot method: FDT
+
+Ad. 13. Similar to case 12, the difference being that <addr3> is the address
+of FDT binary blob that is to be passed to the kernel.
+- boot method: FDT
+
+Ad. 14. Equivalent to case 7: boot kernel stored in <subimg1> from the image
+at <addr1>, without initrd, and pass FDT blob <subimg3> from the image at
+<addr3>.
+- boot method: FDT
+
+Ad. 15. Similar to case 14, the difference being that <addr3> is the address
+of the FDT binary blob that is to be passed to the kernel.
+- boot method: FDT
+
+
+New uImage argument syntax
+--------------------------
+
+New uImage support introduces two new forms for bootm arguments, with the
+following syntax:
+
+- new uImage sub-image specification
+<addr>:<sub-image unit_name>
+
+- new uImage configuration specification
+<addr>#<configuration unit_name>
+
+
+Examples:
+
+- boot kernel "kernel@1" stored in a new uImage located at 200000:
+bootm 200000:kernel@1
+
+- boot configuration "cfg@1" from a new uImage located at 200000:
+bootm 200000#cfg@1
+
+- boot "kernel@1" from a new uImage at 200000 with initrd "ramdisk@2" found in
+  some other new uImage stored at address 800000:
+bootm 200000:kernel@1 800000:ramdisk@2
+
+- boot "kernel@2" from a new uImage at 200000, with initrd "ramdisk@1" and FDT
+  "fdt@1", both stored in some other new uImage located at 800000:
+bootm 200000:kernel@1 800000:ramdisk@1 800000:fdt@1
+
+- boot kernel "kernel@2" with initrd "ramdisk@2", both stored in a new uImage
+  at address 200000, with a raw FDT blob stored at address 600000:
+bootm 200000:kernel@2 200000:ramdisk@2 600000
+
+- boot kernel "kernel@2" from new uImage at 200000 with FDT "fdt@1" from the
+  same new uImage:
+bootm 200000:kernel@2 - 200000:fdt@1
+
+
+Note on current image address
+-----------------------------
+
+When bootm is called without arguments, the image at current image address is
+booted. The current image address is the address set most recently by a load
+command, etc, and is by default equal to CFG_LOAD_ADDR. For example, consider
+the following commands:
+
+tftp 200000 /tftpboot/kernel
+bootm
+Last command is equivalent to:
+bootm 200000
+
+In case of the new uImage argument syntax, the address portion of any argument
+can be omitted. If <addr3> is omitted, then it is assumed that image at
+<addr2> should be used. Similarly, when <addr2> is omitted, is is assumed that
+image at <addr1> should be used. If <addr1> is omitted, it is assumed that the
+current image address is to be used. For example, consider the following
+commands:
+
+tftp 200000 /tftpboot/uImage
+bootm :kernel@1
+Last command is equivalent to:
+bootm 200000:kernel@1
+
+tftp 200000 /tftpboot/uImage
+bootm 400000:kernel@1 :ramdisk@1
+Last command is equivalent to:
+bootm 400000:kernel@1 400000:ramdisk@1
+
+tftp 200000 /tftpboot/uImage
+bootm :kernel@1 400000:ramdisk@1 :fdt@1
+Last command is equivalent to:
+bootm 200000:kernel@1 400000:ramdisk@1 400000:fdt@1

doc/uImage.FIT/howto.txt

@@ -0,0 +1,296 @@
+How to use images in the new image format
+=========================================
+
+Author: Bartlomiej Sieka <tur@semihalf.com>
+
+
+Overview
+--------
+
+The new uImage format allows more flexibility in handling images of various
+types (kernel, ramdisk, etc.), it also enhances integrity protection of images
+with sha1 and md5 checksums.
+
+Two auxiliary tools are needed on the development host system in order to
+create an uImage in the new format: mkimage and dtc, although only one
+(mkimage) is invoked directly. dtc is called from within mkimage and operates
+behind the scenes, but needs to be present in the $PATH nevertheless. It is
+important that the dtc used has support for binary includes -- refer to
+www.jdl.com for its latest version. mkimage (together with dtc) takes as input
+an image source file, which describes the contents of the image and defines
+its various properties used during booting. By convention, image source file
+has the ".its" extension, also, the details of its format are given in
+doc/source_file_format.txt. The actual data that is to be included in the
+uImage (kernel, ramdisk, etc.) is specified in the image source file in the
+form of paths to appropriate data files. The outcome of the image creation
+process is a binary file (by convention with the ".itb" extension) that
+contains all the referenced data (kernel, ramdisk, etc.) and other information
+needed by U-Boot to handle the uImage properly. The uImage file is then
+transferred to the target (e.g., via tftp) and booted using the bootm command.
+
+To summarize the prerequisites needed for new uImage creation:
+- mkimage
+- dtc (with support for binary includes)
+- image source file (*.its)
+- image data file(s)
+
+
+Here's a graphical overview of the image creation and booting process:
+
+image source file     mkimage + dtc               transfer to target
+        +            ---------------> image file --------------------> bootm
+image data files(s)
+
+
+Example 1 -- old-style (non-FDT) kernel booting
+-----------------------------------------------
+
+Consider a simple scenario, where a PPC Linux kernel built from sources on the
+development host is to be booted old-style (non-FDT) by U-Boot on an embedded
+target. Assume that the outcome of the build is vmlinux.bin.gz, a file which
+contains a gzip-compressed PPC Linux kernel (the only data file in this case).
+The uImage can be produced using the image source file examples/kernel.its
+(note that kernel.its assumes that vmlinux.bin.gz is in the current working
+directory; if desired, an alternative path can be specified in the kernel.its
+file). Here's how to create the image and inspect its contents:
+
+[on the host system]
+$ mkimage -f kernel.its kernel.itb
+DTC: dts->dtb  on file "kernel.its"
+$
+$ mkimage -l kernel.itb
+FIT description: Simple image with single Linux kernel
+Created:         Tue Mar 11 17:26:15 2008
+ Image 0 (kernel@1)
+  Description:  Vanilla Linux kernel
+  Type:         Kernel Image
+  Compression:  gzip compressed
+  Data Size:    943347 Bytes = 921.24 kB = 0.90 MB
+  Architecture: PowerPC
+  OS:           Linux
+  Load Address: 0x00000000
+  Entry Point:  0x00000000
+  Hash algo:    crc32
+  Hash value:   2ae2bb40
+  Hash algo:    sha1
+  Hash value:   3c200f34e2c226ddc789240cca0c59fc54a67cf4
+ Default Configuration: 'config@1'
+ Configuration 0 (config@1)
+  Description:  Boot Linux kernel
+  Kernel:       kernel@1
+
+
+The resulting image file kernel.itb can be now transferred to the target,
+inspected and booted (note that first three U-Boot commands below are shown
+for completeness -- they are part of the standard booting procedure and not
+specific to the new image format).
+
+[on the target system]
+=> print nfsargs
+nfsargs=setenv bootargs root=/dev/nfs rw nfsroot=${serverip}:${rootpath}
+=> print addip
+addip=setenv bootargs ${bootargs} ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}:${netdev}:off panic=1
+=> run nfsargs addip
+=> tftp 900000 /path/to/tftp/location/kernel.itb
+Using FEC ETHERNET device
+TFTP from server 192.168.1.1; our IP address is 192.168.160.5
+Filename '/path/to/tftp/location/kernel.itb'.
+Load address: 0x900000
+Loading: #################################################################
+done
+Bytes transferred = 944464 (e6950 hex)
+=> iminfo
+
+## Checking Image at 00900000 ...
+   FIT image found
+   FIT description: Simple image with single Linux kernel
+   Created:         2008-03-11  16:26:15 UTC
+    Image 0 (kernel@1)
+     Description:  Vanilla Linux kernel
+     Type:         Kernel Image
+     Compression:  gzip compressed
+     Data Start:   0x009000e0
+     Data Size:    943347 Bytes = 921.2 kB
+     Architecture: PowerPC
+     OS:           Linux
+     Load Address: 0x00000000
+     Entry Point:  0x00000000
+     Hash algo:    crc32
+     Hash value:   2ae2bb40
+     Hash algo:    sha1
+     Hash value:   3c200f34e2c226ddc789240cca0c59fc54a67cf4
+    Default Configuration: 'config@1'
+    Configuration 0 (config@1)
+     Description:  Boot Linux kernel
+     Kernel:       kernel@1
+
+=> bootm
+## Booting kernel from FIT Image at 00900000 ...
+   Using 'config@1' configuration
+   Trying 'kernel@1' kernel subimage
+     Description:  Vanilla Linux kernel
+     Type:         Kernel Image
+     Compression:  gzip compressed
+     Data Start:   0x009000e0
+     Data Size:    943347 Bytes = 921.2 kB
+     Architecture: PowerPC
+     OS:           Linux
+     Load Address: 0x00000000
+     Entry Point:  0x00000000
+     Hash algo:    crc32
+     Hash value:   2ae2bb40
+     Hash algo:    sha1
+     Hash value:   3c200f34e2c226ddc789240cca0c59fc54a67cf4
+   Verifying Hash Integrity ... crc32+ sha1+ OK
+   Uncompressing Kernel Image ... OK
+Memory BAT mapping: BAT2=256Mb, BAT3=0Mb, residual: 0Mb
+Linux version 2.4.25 (m8@hekate) (gcc version 4.0.0 (DENX ELDK 4.0 4.0.0)) #2 czw lip 5 17:56:18 CEST 2007
+On node 0 totalpages: 65536
+zone(0): 65536 pages.
+zone(1): 0 pages.
+zone(2): 0 pages.
+Kernel command line: root=/dev/nfs rw nfsroot=192.168.1.1:/opt/eldk-4.1/ppc_6xx ip=192.168.160.5:192.168.1.1::255.255.0.0:lite5200b:eth0:off panic=1
+Calibrating delay loop... 307.20 BogoMIPS
+
+
+Example 2 -- new-style (FDT) kernel booting
+-------------------------------------------
+
+Consider another simple scenario, where a PPC Linux kernel is to be booted
+new-style, i.e., with a FDT blob. In this case there are two prerequisite data
+files: vmlinux.bin.gz (Linux kernel) and target.dtb (FDT blob). The uImage can
+be produced using image source file examples/kernel_fdt.its like this (note
+again, that both prerequisite data files are assumed to be present in the
+current working directory -- image source file kernel_fdt.its can be modified
+to take the files from some other location if needed):
+
+[on the host system]
+$ mkimage -f kernel_fdt.its kernel_fdt.itb
+DTC: dts->dtb  on file "kernel_fdt.its"
+$
+$ 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)
+  Description:  Vanilla Linux kernel
+  Type:         Kernel Image
+  Compression:  gzip compressed
+  Data Size:    1092037 Bytes = 1066.44 kB = 1.04 MB
+  Architecture: PowerPC
+  OS:           Linux
+  Load Address: 0x00000000
+  Entry Point:  0x00000000
+  Hash algo:    crc32
+  Hash value:   2c0cc807
+  Hash algo:    sha1
+  Hash value:   264b59935470e42c418744f83935d44cdf59a3bb
+ Image 1 (fdt@1)
+  Description:  Flattened Device Tree blob
+  Type:         Flat Device Tree
+  Compression:  uncompressed
+  Data Size:    16384 Bytes = 16.00 kB = 0.02 MB
+  Architecture: PowerPC
+  Hash algo:    crc32
+  Hash value:   0d655d71
+  Hash algo:    sha1
+  Hash value:   25ab4e15cd4b8a5144610394560d9c318ce52def
+ Default Configuration: 'conf@1'
+ Configuration 0 (conf@1)
+  Description:  Boot Linux kernel with FDT blob
+  Kernel:       kernel@1
+  FDT:          fdt@1
+
+
+The resulting image file kernel_fdt.itb can be now transferred to the target,
+inspected and booted:
+
+[on the target system]
+=> tftp 900000 /path/to/tftp/location/kernel_fdt.itb
+Using FEC ETHERNET device
+TFTP from server 192.168.1.1; our IP address is 192.168.160.5
+Filename '/path/to/tftp/location/kernel_fdt.itb'.
+Load address: 0x900000
+Loading: #################################################################
+         ###########
+done
+Bytes transferred = 1109776 (10ef10 hex)
+=> iminfo
+
+## Checking Image at 00900000 ...
+   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)
+     Description:  Vanilla Linux kernel
+     Type:         Kernel Image
+     Compression:  gzip compressed
+     Data Start:   0x009000ec
+     Data Size:    1092037 Bytes =  1 MB
+     Architecture: PowerPC
+     OS:           Linux
+     Load Address: 0x00000000
+     Entry Point:  0x00000000
+     Hash algo:    crc32
+     Hash value:   2c0cc807
+     Hash algo:    sha1
+     Hash value:   264b59935470e42c418744f83935d44cdf59a3bb
+    Image 1 (fdt@1)
+     Description:  Flattened Device Tree blob
+     Type:         Flat Device Tree
+     Compression:  uncompressed
+     Data Start:   0x00a0abdc
+     Data Size:    16384 Bytes = 16 kB
+     Architecture: PowerPC
+     Hash algo:    crc32
+     Hash value:   0d655d71
+     Hash algo:    sha1
+     Hash value:   25ab4e15cd4b8a5144610394560d9c318ce52def
+    Default Configuration: 'conf@1'
+    Configuration 0 (conf@1)
+     Description:  Boot Linux kernel with FDT blob
+     Kernel:       kernel@1
+     FDT:          fdt@1
+=> bootm
+## Booting kernel from FIT Image at 00900000 ...
+   Using 'conf@1' configuration
+   Trying 'kernel@1' kernel subimage
+     Description:  Vanilla Linux kernel
+     Type:         Kernel Image
+     Compression:  gzip compressed
+     Data Start:   0x009000ec
+     Data Size:    1092037 Bytes =  1 MB
+     Architecture: PowerPC
+     OS:           Linux
+     Load Address: 0x00000000
+     Entry Point:  0x00000000
+     Hash algo:    crc32
+     Hash value:   2c0cc807
+     Hash algo:    sha1
+     Hash value:   264b59935470e42c418744f83935d44cdf59a3bb
+   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
+     Description:  Flattened Device Tree blob
+     Type:         Flat Device Tree
+     Compression:  uncompressed
+     Data Start:   0x00a0abdc
+     Data Size:    16384 Bytes = 16 kB
+     Architecture: PowerPC
+     Hash algo:    crc32
+     Hash value:   0d655d71
+     Hash algo:    sha1
+     Hash value:   25ab4e15cd4b8a5144610394560d9c318ce52def
+   Verifying Hash Integrity ... crc32+ sha1+ OK
+   Booting using the fdt blob at 0xa0abdc
+   Loading Device Tree to 007fc000, end 007fffff ... OK
+[    0.000000] Using lite5200 machine description
+[    0.000000] Linux version 2.6.24-rc6-gaebecdfc (m8@hekate) (gcc version 4.0.0 (DENX ELDK 4.1 4.0.0)) #1 Sat Jan 12 15:38:48 CET 2008
+
+
+Example 3 -- advanced booting
+-----------------------------
+
+Refer to examples/multi.its for an image source file that allows more
+sophisticated booting scenarios (multiple kernels, ramdisks and fdt blobs).

doc/uImage.FIT/kernel.its

@@ -0,0 +1,34 @@
+/*
+ * Simple U-boot uImage source file containing a single kernel
+ */
+/ {
+	description = "Simple image with single Linux kernel";
+	#address-cells = <1>;
+
+	images {
+		kernel@1 {
+			description = "Vanilla Linux kernel";
+			data = /incbin/("./vmlinux.bin.gz");
+			type = "kernel";
+			arch = "ppc";
+			os = "linux";
+			compression = "gzip";
+			load = <00000000>;
+			entry = <00000000>;
+			hash@1 {
+				algo = "crc32";
+			};
+			hash@2 {
+				algo = "sha1";
+			};
+		};
+	};
+
+	configurations {
+		default = "config@1";
+		config@1 {
+			description = "Boot Linux kernel";
+			kernel = "kernel@1";
+		};
+	};
+};

doc/uImage.FIT/kernel_fdt.its

@@ -0,0 +1,48 @@
+/*
+ * Simple U-boot uImage source file containing a single kernel and FDT blob
+ */
+/ {
+	description = "Simple image with single Linux kernel and FDT blob";
+	#address-cells = <1>;
+
+	images {
+		kernel@1 {
+			description = "Vanilla Linux kernel";
+			data = /incbin/("./vmlinux.bin.gz");
+			type = "kernel";
+			arch = "ppc";
+			os = "linux";
+			compression = "gzip";
+			load = <00000000>;
+			entry = <00000000>;
+			hash@1 {
+				algo = "crc32";
+			};
+			hash@2 {
+				algo = "sha1";
+			};
+		};
+		fdt@1 {
+			description = "Flattened Device Tree blob";
+			data = /incbin/("./target.dtb");
+			type = "flat_dt";
+			arch = "ppc";
+			compression = "none";
+			hash@1 {
+				algo = "crc32";
+			};
+			hash@2 {
+				algo = "sha1";
+			};
+		};
+	};
+
+	configurations {
+		default = "conf@1";
+		conf@1 {
+			description = "Boot Linux kernel with FDT blob";
+			kernel = "kernel@1";
+			fdt = "fdt@1";
+		};
+	};
+};

doc/uImage.FIT/multi.its

@@ -0,0 +1,124 @@
+/*
+ * U-boot uImage source file with multiple kernels, ramdisks and FDT blobs
+ */
+/ {
+	description = "Various kernels, ramdisks and FDT blobs";
+	#address-cells = <1>;
+
+	images {
+		kernel@1 {
+			description = "vanilla-2.6.23";
+			data = /incbin/("./vmlinux.bin.gz");
+			type = "kernel";
+			arch = "ppc";
+			os = "linux";
+			compression = "gzip";
+			load = <00000000>;
+			entry = <00000000>;
+			hash@1 {
+				algo = "md5";
+			};
+			hash@2 {
+				algo = "sha1";
+			};
+		};
+
+		kernel@2 {
+			description = "2.6.23-denx";
+			data = /incbin/("./2.6.23-denx.bin.gz");
+			type = "kernel";
+			arch = "ppc";
+			os = "linux";
+			compression = "gzip";
+			load = <00000000>;
+			entry = <00000000>;
+			hash@1 {
+				algo = "sha1";
+			};
+		};
+
+		kernel@3 {
+			description = "2.4.25-denx";
+			data = /incbin/("./2.4.25-denx.bin.gz");
+			type = "kernel";
+			arch = "ppc";
+			os = "linux";
+			compression = "gzip";
+			load = <00000000>;
+			entry = <00000000>;
+			hash@1 {
+				algo = "md5";
+			};
+		};
+
+		ramdisk@1 {
+			description = "eldk-4.2-ramdisk";
+			data = /incbin/("./eldk-4.2-ramdisk");
+			type = "ramdisk";
+			arch = "ppc";
+			compression = "gzip";
+			hash@1 {
+				algo = "sha1";
+			};
+		};
+
+		ramdisk@2 {
+			description = "eldk-3.1-ramdisk";
+			data = /incbin/("./eldk-3.1-ramdisk");
+			type = "ramdisk";
+			arch = "ppc";
+			compression = "gzip";
+			hash@1 {
+				algo = "crc32";
+			};
+		};
+
+		fdt@1 {
+			description = "tqm5200-fdt";
+			data = /incbin/("./tqm5200.dtb");
+			type = "flat_dt";
+			arch = "ppc";
+			compression = "none";
+			hash@1 {
+				algo = "crc32";
+			};
+		};
+
+		fdt@2 {
+			description = "tqm5200s-fdt";
+			data = /incbin/("./tqm5200s.dtb");
+			type = "flat_dt";
+			arch = "ppc";
+			compression = "none";
+			load = <00700000>;
+			hash@1 {
+				algo = "sha1";
+			};
+		};
+
+	};
+
+	configurations {
+		default = "config@1";
+
+		config@1 {
+			description = "tqm5200 vanilla-2.6.23 configuration";
+			kernel = "kernel@1";
+			ramdisk = "ramdisk@1";
+			fdt = "fdt@1";
+		};
+
+		config@2 {
+			description = "tqm5200s denx-2.6.23 configuration";
+			kernel = "kernel@2";
+			ramdisk = "ramdisk@1";
+			fdt = "fdt@2";
+		};
+
+		config@3 {
+			description = "tqm5200s denx-2.4.25 configuration";
+			kernel = "kernel@3";
+			ramdisk = "ramdisk@2";
+		};
+	};
+};

doc/uImage.FIT/source_file_format.txt

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+U-boot new uImage source file format (bindings definition)
+==========================================================
+
+Author: Marian Balakowicz <m8@semihalf.com>
+
+1) Introduction
+---------------
+
+Evolution of the 2.6 Linux kernel for embedded PowerPC systems introduced new
+booting method which requires that hardware description is available to the
+kernel in the form of Flattened Device Tree.
+
+Booting with a Flattened Device Tree is much more flexible and is intended to
+replace direct passing of 'struct bd_info' which was used to boot pre-FDT
+kernels.
+
+However, U-boot needs to support both techniques to provide backward
+compatibility for platforms which are not FDT ready. Number of elements
+playing role in the booting process has increased and now includes the FDT
+blob. Kernel image, FDT blob and possibly ramdisk image - all must be placed
+in the system memory and passed to bootm as a arguments. Some of them may be
+missing: FDT is not present for legacy platforms, ramdisk is always optional.
+Additionally, old uImage format has been extended to support multi sub-images
+but the support is limited by simple format of the legacy uImage structure.
+Single binary header 'struct image_header' is not flexible enough to cover all
+possible scenarios.
+
+All those factors combined clearly show that there is a need for new, more
+flexible, multi component uImage format.
+
+
+2) New uImage format assumptions
+--------------------------------
+
+a) Implementation
+
+Libfdt has been selected for the new uImage format implementation as (1) it
+provides needed functionality, (2) is actively maintained and developed and
+(3) increases code reuse as it is already part of the U-boot source tree.
+
+b) Terminology
+
+This document defines new uImage structure by providing FDT bindings for new
+uImage internals. Bindings are defined from U-boot perspective, i.e. describe
+final form of the uImage at the moment when it reaches U-boot. User
+perspective may be simpler, as some of the properties (like timestamps and
+hashes) will need to be filled in automatically by the U-boot mkimage tool.
+
+To avoid confusion with the kernel FDT the following naming convention is
+proposed for the new uImage format related terms:
+
+FIT	- Flattened uImage Tree
+
+FIT is formally a flattened device tree (in the libfdt meaning), which
+conforms to bindings defined in this document.
+
+.its	- image tree source
+.itb	- image tree blob
+
+c) Image building procedure
+
+The following picture shows how the new uImage is prepared. Input consists of
+image source file (.its) and a set of data files. Image is created with the
+help of standard U-boot mkimage tool which in turn uses dtc (device tree
+compiler) to produce image tree blob (.itb).  Resulting .itb file is is the
+actual binary of a new uImage.
+
+
+tqm5200.its
++
+vmlinux.bin.gz     mkimage + dtc               xfer to target
+eldk-4.2-ramdisk  --------------> tqm5200.itb --------------> bootm
+tqm5200.dtb                          /|\
+...                                   |
+                                 'new uImage'
+
+	- create .its file, automatically filled-in properties are omitted
+	- call mkimage tool on a .its file
+	- mkimage calls dtc to create .itb image and assures that
+	  missing properties are added
+	- .itb (new uImage) is uploaded onto the target and used therein
+
+
+d) Unique identifiers
+
+To identify FIT sub-nodes representing images, hashes, configurations (which
+are defined in the following sections), the "unit name" of the given sub-node
+is used as it's identifier as it assures uniqueness without additional
+checking required.
+
+
+3) Root node properties
+-----------------------
+
+Root node of the uImage Tree should have the following layout:
+
+/ o image-tree
+    |- description = "image description"
+    |- timestamp = <12399321>
+    |- #address-cells = <1>
+    |
+    o images
+    | |
+    | o img@1 {...}
+    | o img@2 {...}
+    | ...
+    |
+    o configurations
+      |- default = "cfg@1"
+      |
+      o cfg@1 {...}
+      o cfg@2 {...}
+      ...
+
+
+  Optional property:
+  - description : Textual description of the uImage
+
+  Mandatory property:
+  - timestamp : Last image modification time being counted in seconds since
+    1970-01-01 00:00:00 - to be automatically calculated by mkimage tool.
+
+  Conditionally mandatory property:
+  - #address-cells : Number of 32bit cells required to represent entry and
+    load addresses supplied within sub-image nodes. May be omitted when no
+    entry or load addresses are used.
+
+  Mandatory node:
+  - images : This node contains a set of sub-nodes, each of them representing
+    single component sub-image (like kernel, ramdisk, etc.). At least one
+    sub-image is required.
+
+  Optional node:
+  - configurations : Contains a set of available configuration nodes and
+    defines a default configuration.
+
+
+4) '/images' node
+-----------------
+
+This node is a container node for component sub-image nodes. Each sub-node of
+the '/images' node should have the following layout:
+
+ o image@1
+   |- description = "component sub-image description"
+   |- data = /incbin/("path/to/data/file.bin")
+   |- type = "sub-image type name"
+   |- arch = "ARCH name"
+   |- os = "OS name"
+   |- compression = "compression name"
+   |- load = <00000000>
+   |- entry = <00000000>
+   |
+   o hash@1 {...}
+   o hash@2 {...}
+   ...
+
+  Mandatory properties:
+  - description : Textual description of the component sub-image
+  - type : Name of component sub-image type, supported types are:
+    "standalone", "kernel", "ramdisk", "firmware", "script", "filesystem",
+    "fdt".
+  - data : Path to the external file which contains this node's binary data.
+  - compression : Compression used by included data. Supported compressions
+    are "gzip" and "bzip2". If no compression is used compression property
+    should be set to "none".
+
+  Conditionally mandatory property:
+  - os : OS name, mandatory for type="kernel", valid OS names are: "openbsd",
+    "netbsd", "freebsd", "4_4bsd", "linux", "svr4", "esix", "solaris", "irix",
+    "sco", "dell", "ncr", "lynxos", "vxworks", "psos", "qnx", "u_boot",
+    "rtems", "artos", "unity".
+  - arch : Architecture name, mandatory for types: "standalone", "kernel",
+    "firmware", "ramdisk" and "fdt". Valid architecture names are: "alpha",
+    "arm", "i386", "ia64", "mips", "mips64", "ppc", "s390", "sh", "sparc",
+    "sparc64", "m68k", "nios", "microblaze", "nios2", "blackfin", "avr32",
+    "st200".
+  - entry : entry point address, address size is determined by
+    '#address-cells' property of the root node. Mandatory for for types:
+    "standalone" and "kernel".
+  - load : load address, address size is determined by '#address-cells'
+    property of the root node. Mandatory for types: "standalone" and "kernel".
+
+  Optional nodes:
+  - hash@1 : Each hash sub-node represents separate hash or checksum
+    calculated for node's data according to specified algorithm.
+
+
+5) Hash nodes
+-------------
+
+o hash@1
+  |- algo = "hash or checksum algorithm name"
+  |- value = [hash or checksum value]
+
+  Mandatory properties:
+  - algo : Algorithm name, supported are "crc32", "md5" and "sha1".
+  - value : Actual checksum or hash value, correspondingly 4, 16 or 20 bytes
+    long.
+
+
+6) '/configurations' node
+-------------------------
+
+The 'configurations' node is optional. If present, it allows to create a
+convenient, labeled boot configurations, which combine together kernel images
+with their ramdisks and fdt blobs.
+
+The 'configurations' node has has the following structure:
+
+o configurations
+  |- default = "default configuration sub-node unit name"
+  |
+  o config@1 {...}
+  o config@2 {...}
+  ...
+
+
+  Optional property:
+  - default : Selects one of the configuration sub-nodes as a default
+    configuration.
+
+  Mandatory nodes:
+  - configuration-sub-node-unit-name : At least one of the configuration
+    sub-nodes is required.
+
+
+7) Configuration nodes
+----------------------
+
+Each configuration has the following structure:
+
+o config@1
+  |- description = "configuration description"
+  |- kernel = "kernel sub-node unit name"
+  |- ramdisk = "ramdisk sub-node unit name"
+  |- fdt = "fdt sub-node unit-name"
+
+
+  Mandatory properties:
+  - description : Textual configuration description.
+  - kernel : Unit name of the corresponding kernel image (image sub-node of a
+    "kernel" type).
+
+  Optional properties:
+  - ramdisk : Unit name of the corresponding ramdisk image (component image
+    node of a "ramdisk" type).
+  - fdt : Unit name of the corresponding fdt blob (component image node of a
+    "fdt type").
+
+The FDT blob is required to properly boot FDT based kernel, so the minimal
+configuration for 2.6 FDT kernel is (kernel, fdt) pair.
+
+Older, 2.4 kernel and 2.6 non-FDT kernel do not use FDT blob, in such cases
+'struct bd_info' must be passed instead of FDT blob, thus fdt property *must
+not* be specified in a configuration node.
+
+
+8) Examples
+-----------
+
+Please see examples/*.its for actual image source files.