| 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 |
| |
| git://git.kernel.org/pub/scm/utils/dtc/dtc.git |
| |
| 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/uImage.FIT/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 file(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 |
| doc/uImage.FIT/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 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 doc/uImage.FIT/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 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 doc/uImage.FIT/multi.its for an image source file that allows more |
| sophisticated booting scenarios (multiple kernels, ramdisks and fdt blobs). |
