Help Getting RAMFS version booting
rtmistler - November 5, 2010
Using MVL6.0 for Z530 I've built a version to boot from RAM disk using the Quickstart initramfs recommendations.
I installed grub2 onto a compact flash and end up at the grub> prompt.
From there I can issue a kernel line to point to my vmLinuz and boot.
There are two problems.
1.) I do not know how to configure grub to just boot and not stick at the prompt; unless there's an error seen in the grub.cfg or other files; hence why it does that.
2.) I do not know how to properly issue the kernel or boot lines so that I can get it fully booted.
I've tried:
"kernel /boot/vmLinuz root=/dev/sda ro" - tells me it can't mount the file system and I end up at the root of the RAM FS
"kernel /boot/vmLinuz root=/dev/sda1 ro" - caused a panic and stuck there about the time it was going to try and mount root
"kernel /boot/vmLinux root=/ ro" - same as the first one, can't mount the file system and drops me to "/" for the RAM FS.
Should I try a different bootloader, or what grub2 configurations am I missing?
I AM a little wary about the grub instal. I did perform grub-install to the mounted /dev/sdx from my development machine and I did modify the device.map to only have /dev/sda - figuring that when I boot my embedded target, the first and only IDE (Compact Flash) will be that device for (hd0). And I did modify the device.map on my development machine prior to doing this because I realize that is where grub-install grabs that information. The other reason is that the /boot/grub directory on the compact flash had very little. I've had to construct a grub.cfg file for it manually; and in comparison to the /boot/grub directory on my development system (Ubuntu 9.10) there are a lot of files not present. Development system has many .mod files, target disk had default, xxx_stage1_5 files only.
Here's what I ended up creating for my grub.cfg:
set default="0"
insmod ext2
set root=(hd0,0)
search --no-floppy
set timeout=0
menuentry "MVL6" {
set quiet=1
insmod ext2
set root=(hd0,0)
search --no-floppy
linux /boot/vmLinuz root=/dev/sda ro
}
Any suggestions?
For booting automatically
For booting automatically without stuck at the prompt, you can copy grub.cfg to /boot/grub and grub will pick it up.
For the grub boot command, my system has 2 partitions - (hd0,1) and (hd0,2). Grub and kernel are on (hd0,1). My rootfs is on (hd0,2). Here are the command I use to boot linux.
linux (hd0,1)/bzImage console=ttyS1,115200n8 noinitrd rw root=/dev/sda2
boot
I used bzImage and rootfs straight out of MVL6 bitbake.
Hope that helps.
Steve
By the way, my grub.cfg looks
By the way, my grub.cfg looks like
set timeout=3
set default=0
menuentry "MVL6-Intel-Atom-Z530" {
linux (hd0,1)/bzImage console=ttyS1,115200n8 noinitrd rw root=/dev/sda2
}
Steve
It helps a bit; however I
It helps a bit; however I still have some difficulties.
There is no way a grub.cfg seems to work for me. I have to use a menu.lst file. Is there a particular reason for that?
I've taken an 8 GB Compact Flash and partitioned it to have two primary ext2 partitions, and make the first partition bootable.
In the menu.lst I have the following:
title MVL-6.0
kernel (hd0,0)/boot/bzImage-2.6.31-r1-intel-atom-z530-initramfs.bin noinitrd root=/dev/sda2 rw quiet
boot
My presumption is that when grub runs it detects the sole drive (Compact Flash via IDE) as /dev/sda.
The misunderstanding on my part is the root file system.
Bitbake creates a gz file for that.
Do I place that on the compact flash intact? And if so, do I place it on /dev/sda2, or in the /dev/sda1/boot directory where my bzImage file is located?
Or ... do I not do that at all and extract that image and copy it recursively onto that second partition? I thought that you could use a compressed file system, but perhaps I'm confused.
If I am supposed to copy that file system onto the compact flash what are the steps? gunzip it first? mount it as a loop? (recommendations needed for how to do that), or gunzip and extract it fully and then cp -R from dev machine to target compact flash?
What happens now is that it boots and when it goes to switch root, it says it sees no /dev/console and then panics.
> There is no way a grub.cfg
> There is no way a grub.cfg seems to work for me. I have to use a menu.lst file. Is there a particular reason for that?
That means you are using older version of GRUB.
> Bitbake creates a gz file for that. Do I place that on the compact flash intact? And if so, do I place it on /dev/sda2, or in the /dev/sda1/boot directory where my bzImage file is located?
The general steps I took to get the filesystem to compactFLASH are
1. Uncompress with with gunzip.
2. Loop mount the uncompressed file
3. Extract the files into a tar.gz with tar -czf
4. Copy the files to /dev/sda2 with tar -xzf
Steve