Thread: Mer v0.6 released
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daperl is offline daperl
2009-01-22 , 02:35
Posts: 2,427 | Thanked: 2,986 times | Joined on Dec 2007
#45
Originally Posted by solca View Post
You need to compile your kernel with CONFIG_BOOT_PRINTK_DELAY set and pass the boot parameter 'boot_delay=X' where X is ms. I pass 100ms and it works without the need for serial-console R&D flag. Please keep us posted on your findings.

I tried to kexec the 2.6.21 kernel from a kexec capable 2.6.28 and it only works with serial-console flag. On the other side a 2.6.28 kexeced kernel works without serial-console flag iff you insert the above printk delays. I didn't tried a 2.6.21 kernel with delays tho.

BTW I have not tried to insert delays before jumping nor switching to slower CPU freqs as I'm not a very bright kernel hacker
Thanks for the info, but I am no kernel hacker. Sometimes I get lucky with a conservative, naive (minimize the variables) approach when I accept that I'm in over my head. Thus, I have a simple goal with a simple approach.

My goal:

To enhance my tablet, not significantly modify it. That means it will work as is with the added ability to kexec into at least one other kernel/OS.

My approach:

I'm currently running an unmodified maemo 5.2008.43-7 kernel (latest Diablo SSU). I will patch this kernel only for successful kexec ability. When I'm satisfied with this kernel I will then:
  • clone an initfs (for this, maybe Nokia's instead of fanoush's) and modify this clone if needed
  • clone my primary OS partition (/dev/mmcblk0p3) and modify this clone if needed
  • add the new kernel to /boot of one of these cloned partitions
  • add a kexec entry to the flash initfs bootmenu for the cloned kernel/initfs/OS
If I can "successfully" boot and run this new entry the goal will be satisfied.

Because I'm very happy with my n800 as is, I would hope that a slightly modified maemo 5.2008.43-7 (2.6.21-omap1) kernel could be a good enough slave/boot kernel for any kernel/OS combination that can be thrown at it. If not, well...

Also, consider this a challenge to the rest of the hack monsters out there to beat me to the punch. Some of you already seem fairly close to the finish line; because of my parenting responsibilities, I probably won't even start patching till Friday. So, on your mark...Get set...Go!

More as I know.
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