[clug] Ubuntu 7.04

[Robert Edwards]

Thanks for the replies.

I have set up various Linuxes in the past to boot from a CF card on an
IDE bus (especially on mini-ITX mobos). That works fine, as Michael
says, it just looks like a regular /dev/hdx to the BIOS and to the
kernel.

One thing that can cause a problem is that write speed on a CF card can
be a whole lot slower than on a regular hard drive and can also "wear"
the flash memory chips. So it is a good idea to use a non-journalling
file-system (like ext2) and to turn off access time updating (with the
"noatime" option to mount in /etc/fstab). This seems to noticably speed
up the system.

Another "trick" I use is to use a RAM-based root filesystem (from
initrd) and to mount stuff like /home, /var and /usr (read-only) from
the drive. Requires some fiddling to work with a standard distribution.

Anyway, what I was hoping for was any good references to what the BIOS
is actually looking for on the USB memory device in order to boot from
it. I have determined that it needs to be a VFAT (or FAT) filesystem,
but where does the kernel need to be and what bootloader works? Has
anyone found any good references on how to "roll your own", or a script
that does it for you?

Cheers,

Bob Edwards.

Michael Cohen wrote:
> Rodney,
>   I have a CF/IDE adapter which makes the CF look exactly like a hdd. It
>   connects to a regular PATA cable. I think its nothing but a connection
>   adapter because the CF itself supports ATA and appears like an IDE device.
>   This kind of CF device will always boot because as far as the mobo is
>   concerned its a hdd. Similarly installation on it is identical to installing
>   on a hdd. (only caveat is i think it does not support slave mode so you can
>   only have one of those per bus)
> 
>   I think if you do a google for a CF/IDE adapter you could get some options.
>   If you like I can try to find its exact model number/manufacturer. I think it
>   cost about $20 quite a few years ago.
> 
>   Michael.
>   
> On Sat, Apr 28, 2007 at 05:37:58PM +1000, Rodney Peters wrote:
>> I have not done this, but the IPCop firewall supports running from CF, without 
>> a HDD.  Their docs, available from http:// www.ipcop.org, give an overview of 
>> the installation process.  However, they are confining their discussions to 
>> those  mini-ITX style mobo which have a CF slot on board in lieu IDE 
>> connector.
>>
>> If you install and setup GRUB on the CF drive, then notionally the kernel 
>> should be bootable (however, the syntax of the "kernel" command would depend 
>> on whether the CF drive is seen as sda, sdb etc).  
>>
>> You would still be up against what boot devices the BIOS supports.  On my 
>> recent mobo, a message appears during POST indicating which "hot-key" to 
>> press to get a menu of boot devices.  For my mobo (both Award-Phoenix BIOS), 
>> pressing Esc and F11 respectively brings up a menu of all bootable devices 
>> (whether they are actually present or not)  Even the later one does not 
>> support booting from USB Card Reader or even USB flash drive.
>>
>>
>> Rod