+.. SPDX-License-Identifier: GPL-2.0+
+
Command syntax extensions for the new uImage format
===================================================
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.
+scenario::
+ 1. bootm boot image at the current address, equivalent to 2,3,8
-1. bootm boot image at the current address, equivalent to 2,3,8
+Old uImage::
-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> */
+ 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>[#<extra-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>
+New uImage::
+ 8. bootm <addr1>
+ 9. bootm [<addr1>]:<subimg1>
+ 10. bootm [<addr1>]#<conf>[#<extra-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:
+ 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 |
+ ======================================================================
+ | 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 support introduces two new forms for bootm arguments, with the
following syntax:
-- new uImage sub-image specification
-<addr>:<sub-image unit_name>
+new uImage sub-image specification
+ <addr>:<sub-image unit_name>
-- new uImage configuration specification
-<addr>#<configuration unit_name>
+new uImage configuration specification
+ <addr>#<configuration unit_name>
-- new uImage configuration specification with extra configuration components
-<addr>#<configuration unit_name>[#<extra configuration unit_name>[#..]]
+new uImage configuration specification with extra configuration components
+ <addr>#<configuration unit_name>[#<extra configuration unit_name>[#..]]
The extra configuration currently is supported only for additional device tree
overlays to apply on the base device tree supplied by the first configuration
Examples:
-- boot kernel "kernel-1" stored in a new uImage located at 200000:
-bootm 200000:kernel-1
+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 configuration "cfg-1" with extra "cfg-2" from a new uImage located
+at 200000::
+
+ bootm 200000#cfg-1#cfg-2
+
+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 configuration "cfg-1" from a new uImage located at 200000:
-bootm 200000#cfg-1
+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::
-- boot configuration "cfg-1" with extra "cfg-2" from a new uImage located
- at 200000:
-bootm 200000#cfg-1#cfg-2
+ bootm 200000:kernel-1 800000:ramdisk-1 800000:fdt-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 "kernel-2" with initrd "ramdisk-2", both stored in a new uImage
+at address 200000, with a raw FDT blob stored at address 600000::
-- 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
+ bootm 200000:kernel-2 200000:ramdisk-2 600000
-- 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::
-- 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
+ 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:
+the following commands::
-tftp 200000 /tftpboot/kernel
-bootm
-Last command is equivalent to:
-bootm 200000
+ 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
+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