[U-Boot-Users] Boot loader on PC (i386) with flash memory

[Jerry Van Baren <gerald.vanbaren@smiths-aerospace.com>]

Martin Kajdas wrote:
> Hello,
> 
> My situation is:
> I have a custom designed flash memory PCI card in a standard PC motherboard (i386) (no floppy, no hard disk, no CD-ROM).
> Everything else is standard (serial, parallel, USB, VGA, network, BIOS).
> The PC does the standard boot and eventually jumps to expansion ROM on my PCI card which does the rest.
> At this point, I trap the INT 19 and when BIOS is finished, I get to boot my code from flash memory on my card.
> 
> My code consists of a Linux kernel with RTAI (real time) extensions, busybox and my application program.
> I tried booting my code from a hard disk (temporarily) and it works well.
> Then, I tried it with BlueCat (LynuxWorks) demo software running from the flash memory and it also worked well.
> But when I found out that LynuxWorks wants $8000 for the privilege of using their software, I decided against it.
> It does too much and I do not need all of their functionality.
> 
> All I need is to create bootable root file system (image), have it in flash and then copy it to RAM and boot from it.
> 
> After finding U-Boot, I believe that it will work form me, with some customizations on my part which I will release back to U-Boot.
> 
> Of course, I do not need all of the power up initialization of the CPU as this is already done by the motherboard's BIOS but the booting of the Linux from flash should be the same.
> 
> My questions:
> - is my thinking correct?
> - was this ever done (I would be surprised if it was not) and is there an easier way (another project)?
> - would this be useful to U-Boot community?
> - any ideas on how to proceed?
> - is anybody interested in such a scenario (PC i386 setup)?
> 
> I appreciate any feedback,
> Martin

Did you look at GRUB?

Did you look at linuxBIOS?
http://linuxbios.org/index.php/Main_Page
http://www.fsf.org/campaigns/free-bios.html

Do you need a second level boot-loader at all?  Between your existing 
BIOS and linux, there is only the task of getting linux copied into RAM 
and jumpped to.  U-boot has 99% overlap with your existing BIOS (and it 
ain't gonna be happy about playing second fiddle).  Linux already knows 
how to run on a PC architecture with very little information from the BIOS.

gvb