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#31 esbeeb

esbeeb

    Neowinian

  • Joined: 01-January 14

Posted 01 January 2014 - 15:39

Karl L.,

 

Firstly kudos for your excellent work so far.  :D

 

I'd like to understand how booting works, after one has followed your instructions.  Am I right that:

  1. The default "verified" uboot bootloader is not used (nor is the alternate "non-verified" nv-uboot bootloader? For more details on nv-uboot, please see "Appendix A: Using nv-U-Boot on the Samsung ARM Chromebook":
    http://www.chromium....-arm-chromebook ).  It seems you somehow use "firmware-linux" and "firmware-libertas" instead.  I've never heard of those (as I'm only familiar with how GRUB works, on PC's).  What are those?  What do they do?
  2. "firmware-linux" and "firmware-libertas" somehow boots a "stock" linux kernel that you compiled and packaged yourself, called "linux-image-exynos5" (as opposed to "borrowing" and "signing" the ChromeOS kernel, which is what one must unfortunately do using the current instructions found on "InstallingDebianOn Samsung ARMChromebook":
    https://wiki.debian....g/ARMChromebook
  3. When future versions of your "linux-image-exynos5" are released (say, because there was an important security update released for the kernel), they'll "just work" (at boot time), when one installs them with "sudo apt-get update && sudo apt-get upgrade"?

If I'm correct on these 3 points, then how were you able to "get away with" not using the nv-uboot bootloader?  That is to say, why couldn't the Debian folks follow suit and boot their own stock linux kernels with "firmware-linux" and "firmware-libertas" like you do?

 

Note: The Debian folks are currently stuck on how to boot a stock linux kernel from nv-u-boot, as seen on
"InstallingDebianOn Samsung ARMChromebook":

https://wiki.debian....g/ARMChromebook


  "Three partitions are created on the disk. In time, the intention is that these be used for:
   - a copy of nv-uboot that is chainloaded by the standard firmware,
   - a /boot filesystem containing the standard (non-ChromeOS) kernel, read by nv-uboot,
   - the root filesystem.

  Currently nv-uboot is *not* used, and so the arrangement is:
   - a copy of the ChromeOS kernel that is loaded by the standard firmware,
   - a /boot filesystem that is used only to contain the ChromeOS kernel (which is not used during booting, just during the preparation of the previous partition),
   - the root filesystem."

 

I would appreciate any clarification, as you seem to understand these things really well.  GPT and "verified" bootloaders are tough to understand, especially when it comes to how to boot stock linux kernels.




#32 esbeeb

esbeeb

    Neowinian

  • Joined: 01-January 14

Posted 03 January 2014 - 14:15

Karl L.,

 

Your work is much appreciated.   :woot:   I write this posting from my new Debian Jesse install on my Samsung ARM Chromebook.

 

A few things could be filled into your procedure:

  • Before doing step 2.3, you didn't mention how to get the Chromebook connected to one's wifi network.  Here's how I did that (well, I'm pretty sure these were the minimal steps that succeeded):
    • ifconfig mlan0 down
    • ifconfig mlan0 essid MySSIDsNameHere key s:MyWifiPasswordHere
    • ifconfig mlan0 up
    • (wait about 15 seconds for the wifi authentication to work)
    • dhclient mlan0
    • (wait a few seconds for a DHCP lease to be assigned)
    • ifconfig mlan0
    • (you should now see a valid DHCP-assigned IP address for "inet addr" on the second line)
  • Before you can do step 2.3, gdisk needs to be installed on the Debian-formatted SD card.  I installed it with:
  • Later in step 2.6, when I tried to run the command "umount /mnt/rar/dev/pts", it wouldn't unmount, as it was "busy".  Nothing except a reboot could clear this up.

I also answered my own questions above as to how booting works:

  • You've left the default uboot "verified" bootloader in place.
  • Your package linux-image-exynos5 provides a kernel which will work with that bootloader
  • To get the bootloader to boot that kernel, the "update-chromebook-vboot" had to be run, which came from your package "chromebook-kernel-vboot"


#33 vics

vics

    Resident One Post Wonder

  • Joined: 31-January 14

Posted 31 January 2014 - 12:20

Is it possible to tailor all that operations to using nv-U-Boot? So that the chromebook booted right away without need to press Ctrl-D etc.?

http://www.chromium....-arm-chromebook



#34 Cull_methi

Cull_methi

    Resident One Post Wonder

  • Joined: 14-February 14

Posted 14 February 2014 - 15:34

 

Karl L.,

 

Your work is much appreciated.   :woot:   I write this posting from my new Debian Jesse install on my Samsung ARM Chromebook.

 

A few things could be filled into your procedure:

  • Before doing step 2.3, you didn't mention how to get the Chromebook connected to one's wifi network.  Here's how I did that (well, I'm pretty sure these were the minimal steps that succeeded):
    • ifconfig mlan0 down
    • ifconfig mlan0 essid MySSIDsNameHere key s:MyWifiPasswordHere
    • ifconfig mlan0 up
    • (wait about 15 seconds for the wifi authentication to work)
    • dhclient mlan0
    • (wait a few seconds for a DHCP lease to be assigned)
    • ifconfig mlan0
    • (you should now see a valid DHCP-assigned IP address for "inet addr" on the second line)

 

 FWIW I also had to use wpa_supplicant here at some point.

 

Also, to OP: I'm getting a weird issue where I can't activate swap space, like at all. When I try to swapon the one we made during the partitioning via (using gparted to swapon) I get:

 

swapon: /dev/mmcblk0p1: found swap signature: version 1, page-size 4, same byte order
swapon: /dev/mmcblk0p1: pagesize = 4096

swapsize = 2251292672, devsize = 2251293184

swapon: /dev/mmcblk0p1: swapon failed: invalid argument

 

Thinking I may have set something up wrong in the partitioning I took a flash drive and formatted it as swap space, plugged it in, and got the same error except with different numbers in line three.

 

Any advice?