[MinnowBoard] Recompiling the kernel of the "core-image-sato-sdk" image.

[Darren Hart]

Excellent, glad it helped.

On 7/6/15, 10:34 AM, "Vasanthi, Jagatha" <jagatha.vasanthi at intel.com>
wrote:

>Hi Darren
>You're right. I was copying the bzImage to the wrong directory and that's
>why it didn't make a difference. Once I mounted the /dev/sda1 and
>followed your instructions, everything worked!
>
>Thanks for your help!
>Vasanthi
>
>-----Original Message-----
>From: Darren Hart [mailto:dvhart at linux.intel.com]
>Sent: Wednesday, July 01, 2015 5:34 PM
>To: MinnowBoard Development and Community Discussion
>Cc: Vasanthi, Jagatha
>Subject: Re: [MinnowBoard] Recompiling the kernel of the
>"core-image-sato-sdk" image.
>
>
>
>On 7/1/15 4:50 PM, Vasanthi, Jagatha wrote:
>>  Hello
>> I'm downloaded the "core-image-sato-sdk" image on the Minnowboard MAX
>>and have had no issues with it so far. But now, I have a need to change
>>some configurations and recompile the kernel. The steps  seem to be
>>working but when I reboot it keeps booting to the old kernel image. I'd
>>like to understand how Minnowboard chooses the kernel image to boot. I
>>looked for a grub config file but could not find it. I would appreciate
>>any leads on this.
>> 
>> These are the steps I followed:
>> 1. cd /usr/src/kernel
>> 2. make menuconfig
>> 3. made changes and saved them to the .config file 4. Changed
>> EXTRAVERSION in Makefile to unique name 5. ran "make"
>> 6. ran "make  modules"
>> 7. ran  "make modules_install"
>> 8. I tried to run "make install" at this point but it complained that
>> it could not find LILO. So I tried the below steps
>
>Interesting... haven't run into that. But I rarely build on target,
>especially not entire kernels.
>
>> 9. cp System.map /boot/System.map-PERFORMANCE 10. ln -sf
>> /boot/System.map-PERFORMANCE /boot/System.map 11. cp
>> arch/x86_64/boot/bzImage /boot/
>
>How are you booting? Which exact image and how did you copy it to your
>boot media?
>
>I suspect copying it to /boot has no effect because that is not the
>kernel being booted by the boot loader. The hddimg is a fat image with an
>EFI/BOOT directory for the bootx64.efi payload. The kernel is in the top
>level directory of the hddimg, but this is NOT /boot. To copy something
>there from the target itself, you need to mount it. If it's a USB drive:
>
>mount /dev/sda /some/path
>cp bzImage /some/path/vmlinuz
>
>I suggest calling it something else, like vmlinuz-test and modifying the
>boot loader to add a target for -test, then if you mess it up, your image
>will still boot.
>
>> 12.  Rebooted but new changes did not take effect. I also tried 'uname
>>-r' and did not see the EXTRAVERSION change that I made.
>> 
>> 
>> When I reboot, I always get into the EFI shell , so I have to run
>>"fs0:" and "bootx64". Is bootx64 a file that I can access and read?
>
>bootx64 is in EFI/BOOT/bootx64.efi, you can make this your default boot
>target by configuring the boot order in the UEFI firmware.
>
>--
>Darren Hart
>Intel Open Source Technology Center
>


-- 
Darren Hart
Intel Open Source Technology Center