[U-Boot-Users] AT91RM9100 board with uCOS-II. What boot loader to use?

shuwn yuan s_yuan31tee at yahoo.com
Wed Mar 8 03:13:43 CET 2006

hi all,

Let me explain more about my case. I know that U-boot is OS-independant
bootloader. If I change to uCOS-II instead of ARM-linux, I can still use
U-boot as bootloader for AT91RM9200. 
Am I right? 
But I know some modification has to be done on the original U-boot for the
ARM-linux version. 

Address mapping (Flash & RAM) for my AT91RM9200 board
0x20000000 = RAM

0x10000000 = parallel flash
         0x10000000 = Boot.bin
         0x10010000 = u-boot.gz
         0x10020000 = zImage (ARM-linux kernel)

0xc0000000 = serial flash
         0xc0000000 = Ramdisk.gz (ARM-linux file system)

Currently, for my ARM-linux version, the "bootcmd" for auto-boot is set as

"bootcmd=cp 10020000 20008000 e0000;cp c0000000 21000000 100000;go 20008000"

It copy kernel image "zImage" which store at 0x10020000 (size = 0xe0000) to
0x20008000 (RAM); copy file system image "Ramdisk.gz" which store at
0xc0000000 (size = 0x100000) to 0x21000000 (RAM); jump to RAM location

Now I change to uCOS-ii as OS, & reprogram parallel flash content as follow:

0x10000000 - Boot.bin
0x10010000 - u-boot.gz
0x10020000 - (uCOS-II + application) binary

For the U-boot, is it just change the environment variable "bootcmd" to

"bootcmd=cp 10020000 20008000 f818;go 20008000"

It means copy the (ucos-ii + application) binary (size = 0xf818) from
0x10020000 to 0x200080000 (RAM); go to RAM location 0x20008000.
Is this all I need to do?
But I try to change the "bootcmp" in U-boot prompt, using this cmd:

Uboot> setenv bootcmd cp 10020000 20008000 f818;go 20008000

But this seems not work. I can't set it successfully. It directly jump to
RAM location 0x20008000 after this & I can't save the "bootcmd".
I expect it to be still in U-boot prompt after I type the above, & then I
should type:

U-boot> saveenv 

to save the "bootcmd" variable. 

How to set the "bootcmd" in U-boot? How to put more than 1 action in
"bootcmd" (eg: cp .....; go.....)? Does it not allow to type ";" ? What
punctuation mark should I use?

Is changing the "bootcmd" enough if change to uCOS-II? Or I need to modify
U-boot source code, recompile, & reprogram the u-boot.gz into parallel
flash? Any reference link online suggested?

Please help. Thanks :-)

View this message in context: http://www.nabble.com/AT91RM9100-board-with-uCOS-II.-What-boot-loader-to-use--t1232449.html#a3293578
Sent from the Uboot - Users forum at Nabble.com.

More information about the U-Boot mailing list