About MLO and uboot.bin

[sureshbalijepalli]

Hi all,

I compiled(using cross toolchain for arm) the kernel on host machine and builded it to a clean build directory.

I founded the builded uImage in arch/arm/boot.

but how and where (i mean in which directory) should i get the MLO and Uboot.bin files.

I should transfer MLO and Uboot.bin and uImage to sdcard to boot my board .

thanks for the help

[Siddly]

MLO and uboot.bin should already be there on the VFAT partition.
You would need to backup/rename the existing UImage and copy the new UImage to the first (VFAT) partition on the SD card.
Mount it first of course.

The modules are in /lib/modules on your PC.
e.g:-
# ls /lib/modules/3.0.0-rc3-git5-omap/
build kernel modules.alias modules.alias.bin modules.builtin modules.builtin.bin modules.dep modules.dep.bin modules.devname modules.order modules.softdep modules.symbols modules.symbols.bin source

# mount the SD card second partition
# mkdir -p /lib/modules/3.0.0-rc3-git5-omap ### on the SD card 2nd partition ###
# cp /lib/modules/3.0.0-rc3-git5-omap/modules.* <sdcard_2nd_partition_mount_point>/ib/modules/3.0.0-rc3-git5-omap
# cp -dpR /lib/modules/3.0.0-rc3-git5-omap/kernel <sdcard_2nd_partition_mount_point>/lib/modules/3.0.0-rc3-git5-omap
# sync
When you boot the SD card, not all the required modules will be loaded.
# depmod -a
Reboot.

[sureshbalijepalli]

Thank you for the reply.

So, the MLO nad uboot.bin are the common boot files or they will change according to kernel.

can you please sujjest me to link where i can find the inner details about mlo and uboot.bin.

What i done before posting my 1st thread was ,my sd card have mlo and uboot.bin and uImage and i just removed the old uImage and placed the newly compiled uImage . At that time i did not placed modules on to the sd card. It starting booting process and displaying booting the kernel and going to freezing state. nothing seen on my terminal.

[Siddly]

Thank you for the reply.

So, the MLO nad uboot.bin are the common boot files or they will change according to kernel.

can you please sujjest me to link where i can find the inner details about mlo and uboot.bin.

What i done before posting my 1st thread was ,my sd card have mlo and uboot.bin and uImage and i just removed the old uImage and placed the newly compiled uImage . At that time i did not placed modules on to the sd card. It starting booting process and displaying booting the kernel and going to freezing state. nothing seen on my terminal.

That's usually a problem with what's specified as a tty, the rev B and rev C use ttyS2 and the -XM uses tty02.
BeagleBoardUbuntu - eLinux.org

[sureshbalijepalli]

as you said i kept the mlo and uboot.bin files os previous i mean ubuntu and i loaded new uImage .

it is going fine but it did not recognising the rootpartion and giving me error

cound not found dev/mmcblk0p2

then i just formatted the sd card in both partions and i placed mlo and uboot.bin files from angstrom and my new uImage on to sd partion .

the builded modules into ext partion . nothing else i done not even any file system also.

then my ext partion is mounting then getting error as below


Kernel panic - not syncing: No init found. Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.




Is this error is because of not loading any filesystem ?

i have builded the kernel with omap2.6 and added xenomai patch.

which file system i have to place on ext partion.

Thanks for help

[Siddly]

If you reformatted your SD card, you would have to start again from the beginning so you have a system you can boot.
There are all the other components you need like utilities and applications.
A new kernel is just an addition or replacement for the original kernel.
The ext3 partition does not hold only a kernel.
When you have a bootable and running system on an existing kernel, you can build and install other kernels to replace the original.
My original used a 2.6.38 kernel, I upgraded the kernel to 2.6.39 and later to 3.0.0-rc5 without replacing or removing anything else.

[sureshbalijepalli]

Yes i agree that you upgraded kernel without much effort but in my case

its a custom kernel . I can not just replace the kernel . That is the reason i

tried to build the rootfs which seems to be not working.

[Siddly]

Yes i agree that you upgraded kernel without much effort but in my case

its a custom kernel . I can not just replace the kernel . That is the reason i

tried to build the rootfs which seems to be not working.

A custom kernel is just another kernel - uImage, modules and initrd if it's used, everything else stays the same.
On Beagleboard some time ago I needed a kernel that supported UAC2 which was not in any of the standard kernels back then. I crosscompiled the kernel, copied across uImage, initrd and modules to the SD card. Booted up and first time most modules weren't loaded, "depmod -ae" and rebooted to a fully working system.

The Beagleboard and linux-omap lists are best if you need specifics as you'll find the kernel and Angstrom developers there.