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Intel processor microcode: two image files on initrd line

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#1 Kirkx



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Posted 02 February 2017 - 08:04 AM

Running Arch Linux on a machine with Intel processor requires loading processor microcode (intel-ucode.img) very early in the boot process, ahead of initial ram disk. So the initrd line would need to look as follows:

initrd /boot/intel-ucode.img /boot/initramfs-linux.img

Below is my menu.lst:

title Arch Linux
root (hd1,4)
kernel /boot/vmlinuz-linux root=UUID=c0af9bh9-39c8-519g-cz4j-87684beg7958 ro
# intel processors only
initrd /boot/intel-ucode.img /boot/initramfs-linux.img

Everything boots and works ok with Grub4Dos v0.4.5c-2014-12-24. Here is the boot log from my Core 2 Duo test machine:

journalctl --boot=d667939e4baf4c7397a9d2ffca2f6742 --output=short-precise
-- Logs begin at Thu 2017-01-26 03:44:17 EST, end at Wed 2017-02-01 22:45:48 EST. --
Feb 01 22:45:07.527460 dc77 kernel: microcode: CPU0 microcode updated early to revision 0x5d, date = 2010-10-02
Feb 01 22:45:07.530905 dc77 kernel: microcode: CPU1 microcode updated early to revision 0x5d, date = 2010-10-02
Feb 01 22:45:07.553866 dc77 kernel: microcode: CPU0 sig=0x6f2, pf=0x1, revision=0x5d
Feb 01 22:45:07.553888 dc77 kernel: microcode: CPU1 sig=0x6f2, pf=0x1, revision=0x5d
Feb 01 22:45:07.553910 dc77 kernel: microcode: Microcode Update Driver: v2.01 <tigran@aivazian.fsnet.co.uk>, Peter Oruba

However, I'm just not sure if two img files placed on a single initrd line are officially supported, or should two separate initrd lines be used instead. Another option mentioned in ArchWiki would be to merge both image files and then have standard initrd line with a single img file:

# concatenate both img files
cat /boot/intel-ucode.img /boot/initramfs-linux.img > /boot/initramfs-merged.img

# use standard initrd with a single img file
initrd /boot/initramfs-merged.img

Below is the link to ArchWiki:



Edited by Kirkx, 02 February 2017 - 08:50 AM.

#2 steve6375


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Posted 02 February 2017 - 09:06 AM

AFAIK, two images or more, placed on the same initrd line in grub4dos is supported and that is how you are suppose to use it.

#3 Wonko the Sane

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Posted 03 February 2017 - 09:36 AM

Yes, grub4dos has been updated (at the time,  2009) to have more than one file as the initrd parameter, this happened originally because of the NT password and of some UBCD files, (linux kernel 2.6x change) should be this one:
2009-02-03 New initrd syntax loading multiple cpio files for Linux 2.6 kernels.

See :


Before that, yes, images had to be merged, example:






#4 Abdul Gafoor

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Posted 22 March 2017 - 07:03 PM

I had the same issue when creating AIO USB. Did some googling and updated one of menu entry as following, which worked perfect for me.

title 6. Parted Magic 32-bit\nA complete hard disk management solution. Version: 2017_03_14
root (hd0,2)/multiboot/pmagic_2017_03_14/pmagic
kernel /bzImage directory=/multiboot/pmagic_2017_03_14/ edd=on vga=normal vmalloc=608MiB
initrd /initrd.img
initrd /fu.img
initrd /m32.img

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