The previous section described how to load the Linux kernel image
over ethernet using
TFTP. This is especially well suited for your
development and test environment, when the kernel image is still
undergoing frequent changes, for instance because you are modifying
kernel code or configuration.
Later in your development cycle you will work on application code or
device drivers, which can be loaded dynamically as modules. If the
Linux kernel remains the same then you can save the time needed for
the
TFTP download and put the kernel image into the flash memory of
your canyonlands board.
The U-Boot command
flinfo can be used to display
information about the available on-board flash on your system:
=> fli
Bank # 1: CFI conformant FLASH (16 x 16) Size: 64 MB in 512 Sectors
AMD Standard command set, Manufacturer ID: 0x01, Device ID: 0x227E
Erase timeout: 16384 ms, write timeout: 2 ms
Buffer write timeout: 5 ms, buffer size: 32 bytes
Sector Start Addresses:
FC000000 FC020000 FC040000 FC060000 FC080000
FC0A0000 FC0C0000 FC0E0000 FC100000 FC120000
FC140000 FC160000 FC180000 FC1A0000 FC1C0000 E
FC1E0000 FC200000 FC220000 FC240000 FC260000
FC280000 FC2A0000 FC2C0000 FC2E0000 FC300000
FC320000 FC340000 FC360000 FC380000 FC3A0000
FC3C0000 E FC3E0000 E FC400000 E FC420000 E FC440000 E
FC460000 E FC480000 E FC4A0000 E FC4C0000 E FC4E0000 E
FC500000 E FC520000 E FC540000 E FC560000 E FC580000 E
FC5A0000 E FC5C0000 E FC5E0000 E FC600000 E FC620000 E
FC640000 E FC660000 E FC680000 E FC6A0000 E FC6C0000 E
FC6E0000 E FC700000 E FC720000 E FC740000 E FC760000 E
FC780000 E FC7A0000 E FC7C0000 E FC7E0000 E FC800000 E
FC820000 E FC840000 E FC860000 E FC880000 E FC8A0000 E
FC8C0000 E FC8E0000 E FC900000 E FC920000 E FC940000 E
FC960000 E FC980000 E FC9A0000 E FC9C0000 E FC9E0000 E
FCA00000 E FCA20000 E FCA40000 E FCA60000 E FCA80000 E
FCAA0000 E FCAC0000 E FCAE0000 E FCB00000 E FCB20000 E
FCB40000 E FCB60000 E FCB80000 E FCBA0000 E FCBC0000 E
FCBE0000 E FCC00000 E FCC20000 E FCC40000 E FCC60000 E
FCC80000 E FCCA0000 E FCCC0000 E FCCE0000 E FCD00000 E
FCD20000 E FCD40000 E FCD60000 E FCD80000 E FCDA0000 E
FCDC0000 E FCDE0000 E FCE00000 E FCE20000 E FCE40000 E
FCE60000 E FCE80000 E FCEA0000 E FCEC0000 E FCEE0000 E
FCF00000 E FCF20000 E FCF40000 E FCF60000 E FCF80000 E
FCFA0000 E FCFC0000 E FCFE0000 E FD000000 E FD020000 E
FD040000 E FD060000 E FD080000 E FD0A0000 E FD0C0000 E
FD0E0000 E FD100000 E FD120000 E FD140000 E FD160000 E
FD180000 E FD1A0000 E FD1C0000 E FD1E0000 E FD200000 E
FD220000 E FD240000 E FD260000 E FD280000 E FD2A0000 E
FD2C0000 E FD2E0000 E FD300000 E FD320000 E FD340000 E
FD360000 E FD380000 E FD3A0000 E FD3C0000 E FD3E0000 E
FD400000 E FD420000 E FD440000 E FD460000 E FD480000 E
FD4A0000 E FD4C0000 E FD4E0000 E FD500000 E FD520000 E
FD540000 E FD560000 E FD580000 E FD5A0000 E FD5C0000 E
FD5E0000 E FD600000 FD620000 E FD640000 E FD660000 E
FD680000 E FD6A0000 E FD6C0000 E FD6E0000 E FD700000 E
FD720000 E FD740000 E FD760000 E FD780000 E FD7A0000 E
FD7C0000 E FD7E0000 E FD800000 E FD820000 E FD840000 E
FD860000 E FD880000 E FD8A0000 E FD8C0000 E FD8E0000 E
FD900000 E FD920000 E FD940000 E FD960000 E FD980000 E
FD9A0000 E FD9C0000 E FD9E0000 E FDA00000 E FDA20000 E
FDA40000 E FDA60000 E FDA80000 E FDAA0000 E FDAC0000 E
FDAE0000 E FDB00000 E FDB20000 E FDB40000 E FDB60000 E
FDB80000 E FDBA0000 E FDBC0000 E FDBE0000 E FDC00000 E
FDC20000 E FDC40000 E FDC60000 E FDC80000 E FDCA0000 E
FDCC0000 E FDCE0000 E FDD00000 E FDD20000 E FDD40000 E
FDD60000 E FDD80000 E FDDA0000 E FDDC0000 E FDDE0000 E
FDE00000 E FDE20000 E FDE40000 E FDE60000 E FDE80000 E
FDEA0000 E FDEC0000 E FDEE0000 E FDF00000 E FDF20000 E
FDF40000 E FDF60000 E FDF80000 E FDFA0000 E FDFC0000 E
FDFE0000 E FE000000 E FE020000 E FE040000 E FE060000 E
FE080000 E FE0A0000 E FE0C0000 E FE0E0000 E FE100000 E
FE120000 E FE140000 E FE160000 E FE180000 E FE1A0000 E
FE1C0000 E FE1E0000 E FE200000 E FE220000 E FE240000 E
FE260000 E FE280000 E FE2A0000 E FE2C0000 E FE2E0000 E
FE300000 E FE320000 E FE340000 E FE360000 E FE380000 E
FE3A0000 E FE3C0000 E FE3E0000 E FE400000 E FE420000 E
FE440000 E FE460000 E FE480000 E FE4A0000 E FE4C0000 E
FE4E0000 E FE500000 E FE520000 E FE540000 E FE560000 E
FE580000 E FE5A0000 E FE5C0000 E FE5E0000 E FE600000 E
FE620000 E FE640000 E FE660000 E FE680000 E FE6A0000 E
FE6C0000 E FE6E0000 E FE700000 E FE720000 E FE740000 E
FE760000 E FE780000 E FE7A0000 E FE7C0000 E FE7E0000 E
FE800000 E FE820000 E FE840000 E FE860000 E FE880000 E
FE8A0000 E FE8C0000 E FE8E0000 E FE900000 E FE920000 E
FE940000 E FE960000 E FE980000 E FE9A0000 E FE9C0000 E
FE9E0000 E FEA00000 E FEA20000 E FEA40000 E FEA60000 E
FEA80000 E FEAA0000 E FEAC0000 E FEAE0000 E FEB00000 E
FEB20000 E FEB40000 E FEB60000 E FEB80000 E FEBA0000 E
FEBC0000 E FEBE0000 E FEC00000 E FEC20000 E FEC40000 E
FEC60000 E FEC80000 E FECA0000 E FECC0000 E FECE0000 E
FED00000 E FED20000 E FED40000 E FED60000 E FED80000 E
FEDA0000 E FEDC0000 E FEDE0000 E FEE00000 E FEE20000 E
FEE40000 E FEE60000 E FEE80000 E FEEA0000 E FEEC0000 E
FEEE0000 E FEF00000 E FEF20000 E FEF40000 E FEF60000 E
FEF80000 E FEFA0000 E FEFC0000 E FEFE0000 E FF000000 E
FF020000 E FF040000 E FF060000 E FF080000 E FF0A0000 E
FF0C0000 E FF0E0000 E FF100000 E FF120000 E FF140000 E
FF160000 E FF180000 E FF1A0000 E FF1C0000 E FF1E0000 E
FF200000 E FF220000 E FF240000 E FF260000 E FF280000 E
FF2A0000 E FF2C0000 E FF2E0000 E FF300000 E FF320000 E
FF340000 E FF360000 E FF380000 E FF3A0000 E FF3C0000 E
FF3E0000 E FF400000 E FF420000 E FF440000 E FF460000 E
FF480000 E FF4A0000 E FF4C0000 E FF4E0000 E FF500000 E
FF520000 E FF540000 E FF560000 E FF580000 E FF5A0000 E
FF5C0000 E FF5E0000 E FF600000 E FF620000 E FF640000 E
FF660000 E FF680000 E FF6A0000 E FF6C0000 E FF6E0000 E
FF700000 E FF720000 E FF740000 E FF760000 E FF780000 E
FF7A0000 E FF7C0000 E FF7E0000 E FF800000 E FF820000 E
FF840000 E FF860000 E FF880000 E FF8A0000 E FF8C0000 E
FF8E0000 E FF900000 E FF920000 E FF940000 E FF960000 E
FF980000 E FF9A0000 E FF9C0000 E FF9E0000 E FFA00000 E
FFA20000 E FFA40000 E FFA60000 E FFA80000 E FFAA0000 E
FFAC0000 E FFAE0000 E FFB00000 E FFB20000 E FFB40000 E
FFB60000 E FFB80000 E FFBA0000 E FFBC0000 E FFBE0000 E
FFC00000 E FFC20000 E FFC40000 E FFC60000 E FFC80000 E
FFCA0000 E FFCC0000 E FFCE0000 E FFD00000 E FFD20000 E
FFD40000 E FFD60000 E FFD80000 E FFDA0000 E FFDC0000 E
FFDE0000 E FFE00000 E FFE20000 E FFE40000 E FFE60000 E
FFE80000 E FFEA0000 E FFEC0000 E FFEE0000 E FFF00000 E
FFF20000 E FFF40000 E FFF60000 RO FFF80000 RO FFFA0000 RO
FFFC0000 RO FFFE0000 RO
=>
From this output you can see the total amount of flash memory, and
how it is divided in blocks (
Erase Units or
Sectors). The
RO markers
show blocks of flash memory that are write protected (by software) -
this is the area where U-Boot is stored. The remaining flash memory
is available for other use.
For instance, we can store the Linux kernel image in flash starting
at the start address of the next free flash sector. Before we can do
this we must make sure that the flash memory in that region is empty
- a Linux kernel image is typically around 600...700 kB, so to be on
the safe side we dedicate the whole area from 0xFC000000 to
0xFC17FFFF for the kernel image. Keep in mind that with
flash memory only whole erase units can be cleared.
After having deleted the target flash area, you can download
the Linux image and write it to flash. Below is a transcript of
the complete operation with a final
iminfo command to check
the newly placed Linux kernel image in the flash memory.
=>
=> setenv kernel_addr FC000000
=>
=> prot off FC000000 FC17FFFF
Un-Protected 12 sectors
=>
=> era FC000000 FC17FFFF
............ done
Erased 12 sectors
=>
=> tftp 100000 /tftpboot/canyonlands/uImage-duts
ENET Speed is 1000 Mbps - FULL duplex connection (EMAC0)
Using ppc_4xx_eth0 device
TFTP from server 192.168.1.1; our IP address is 192.168.100.6
Filename '/tftpboot/canyonlands/uImage-duts'.
Load address: 0x100000
Loading: *#################################################################
######################################################
done
Bytes transferred = 1744326 (1a9dc6 hex)
=>
=> imi 100000
## Checking Image at 00100000 ...
Legacy image found
Image Name: Linux-2.6.25-rc8-01016-g94bf13b-
Created: 2008-04-10 9:50:08 UTC
Image Type: PowerPC Linux Kernel Image (gzip compressed)
Data Size: 1744262 Bytes = 1.7 MB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
=>
=> setenv ram_ws 100000
=>
=> cp.b ${ram_ws} ${kernel_addr} ${filesize}
Copy to Flash... done
=>
=> iminfo ${kernel_addr}
## Checking Image at fc000000 ...
Legacy image found
Image Name: Linux-2.6.25-rc8-01016-g94bf13b-
Created: 2008-04-10 9:50:08 UTC
Image Type: PowerPC Linux Kernel Image (gzip compressed)
Data Size: 1744262 Bytes = 1.7 MB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
=>
=> saveenv
Saving Environment to Flash...
Un-Protected 1 sectors
Un-Protected 1 sectors
Erasing Flash...
. done
Erased 1 sectors
Writing to Flash... done
Protected 1 sectors
Protected 1 sectors
=>
Note how the
filesize variable (which gets set by
the
TFTP transfer) is used to automatically adjust for the actual
image size.
Since kernel requires the flattened device tree blob to be passed at boot time, you have to also write the blob to the flash memory. Below is a transcript of this operation.
=>
=> setenv fdt_addr FC1E0000
=>
=> prot off FC1E0000 FC1FFFFF
Un-Protected 1 sectors
=>
=> era FC1E0000 FC1FFFFF
. done
Erased 1 sectors
=>
=> tftp 100000 /tftpboot/canyonlands/canyonlands.dtb
Waiting for PHY auto negotiation to complete... done
ENET Speed is 1000 Mbps - FULL duplex connection (EMAC0)
Using ppc_4xx_eth0 device
TFTP from server 192.168.1.1; our IP address is 192.168.100.6
Filename '/tftpboot/canyonlands/canyonlands.dtb'.
Load address: 0x100000
Loading: *T #
done
Bytes transferred = 10000 (2710 hex)
=>
=> md 100000
00100000: d00dfeed 00002710 000000b8 00001b08 ......'.........
00100010: 00000028 00000011 00000010 00000000 ...(............
00100020: 000002f5 00001a50 00000000 00000000 .......P........
00100030: 00000000 00000000 00000000 00000000 ................
00100040: 00000000 00000000 00000000 00000000 ................
00100050: 00000000 00000000 00000000 00000000 ................
00100060: 00000000 00000000 00000000 00000000 ................
00100070: 00000000 00000000 00000000 00000000 ................
00100080: 00000000 00000000 00000000 00000000 ................
00100090: 00000000 00000000 00000000 00000000 ................
001000a0: 00000000 00000000 00000000 00000000 ................
001000b0: 00000000 00000000 00000001 00000000 ................
001000c0: 00000003 00000004 00000000 00000002 ................
001000d0: 00000003 00000004 0000000f 00000001 ................
001000e0: 00000003 00000011 0000001b 616d6363 ............amcc
001000f0: 2c63616e 796f6e6c 616e6473 00000000 ,canyonlands....
=>
=> setenv ram_ws 100000
=>
=> cp.b ${ram_ws} ${fdt_addr} ${filesize}
Copy to Flash... done
=>
=> md ${fdt_addr}
fc1e0000: d00dfeed 00002710 000000b8 00001b08 ......'.........
fc1e0010: 00000028 00000011 00000010 00000000 ...(............
fc1e0020: 000002f5 00001a50 00000000 00000000 .......P........
fc1e0030: 00000000 00000000 00000000 00000000 ................
fc1e0040: 00000000 00000000 00000000 00000000 ................
fc1e0050: 00000000 00000000 00000000 00000000 ................
fc1e0060: 00000000 00000000 00000000 00000000 ................
fc1e0070: 00000000 00000000 00000000 00000000 ................
fc1e0080: 00000000 00000000 00000000 00000000 ................
fc1e0090: 00000000 00000000 00000000 00000000 ................
fc1e00a0: 00000000 00000000 00000000 00000000 ................
fc1e00b0: 00000000 00000000 00000001 00000000 ................
fc1e00c0: 00000003 00000004 00000000 00000002 ................
fc1e00d0: 00000003 00000004 0000000f 00000001 ................
fc1e00e0: 00000003 00000011 0000001b 616d6363 ............amcc
fc1e00f0: 2c63616e 796f6e6c 616e6473 00000000 ,canyonlands....
=>
=> setenv filesize
=>
=> saveenv
Saving Environment to Flash...
Un-Protected 1 sectors
Un-Protected 1 sectors
Erasing Flash...
. done
Erased 1 sectors
Writing to Flash... done
Protected 1 sectors
Protected 1 sectors
=>
Now we can boot directly from flash. All we need to do is passing the
in-flash address of the image (FC000000)
and the in-flash address of the flattened device tree (FC1E0000) with the
bootm
command; we also make the definition of the
bootargs variable permanent now:
=> setenv bootcmd bootm FC000000 - FC1E0000
=> setenv bootargs root=/dev/nfs rw nfsroot=${serverip}:${rootpath} ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off
Use
printenv to verify that everything is OK before you save the
environment settings:
=> printenv
bootdelay=5
baudrate=115200
stdin=serial
stdout=serial
stderr=serial
bootcmd=bootm FC000000 - FC1E0000
bootargs=root=/dev/nfs rw nfsroot=192.168.1.1:/opt/eldk-4.2/ppc_4xx
ip=192.168.100.6:192.168.1.1:192.168.1.1:255.255.0.0:canyonlands::off
....
=> saveenv
To test booting from flash you can now reset the board (either by
power-cycling it, or using the U-Boot command
reset), or you can manually call the
boot command which will run the commands in the
bootcmd variable:
Note: Included topic
DULGData.canyonlandsLinuxBootSelf? does not exist yet
