61ffc17aeb
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Acked-by: Simon Glass <sjg@chromium.org>
192 lines
6.8 KiB
Plaintext
192 lines
6.8 KiB
Plaintext
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 CONFIG_SYS_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, it 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
|