what happens if I use olpc-boot.sh to point to my kernel, and my kernel does not work? Is there a way to return from that situation?
Your recent edits on LinuxBIOS are incorrect. Using LAB (or OFW) in the ROM saves absolutely no space on the flash storage - the two sets of bits are independent of each other. The original assertation that the larger ROM eliminated the cost benefit from saving the BIOS royalty is, AFAIK still valid. I have reverted the incorrect comments accordingly. - JordanCrouse (Talk to me!) 21:07, 5 December 2006 (EST)
"On other systems, for example ones on which one can write protect main flash pages, one might put the Linux image being used as a bootloader into such write protected pages. The NAND flash on our system lacks page level write protect bits, and therefore for robustness sake, we decided we want Linux as bootloader to also fit into the the ROM with LinuxBIOS (and the embedded controller code). The actual cost turned out to be almost identical to using a commercial BIOS."
- Your claim about memory usage makes no sense to me. If you put a Linux image in the BIOS ROM, then you don't need one in main storage. The text on the page, quoted just above, specifically describes this option.--Mokurai 21:42, 5 December 2006 (EST)
- In the actual LAB solution, a minimal Linux kernel is used as a bootstrap to bring up the storage, video and USB devices, and then load a full kernel from the flash storage using kexec. Even a 1MB ROM doesn't have enough space to store the full olpc kernel (not to mention all the modules that we need to support USB and other hotpluggable busses). It also doesn't make sense from a technical standpoint - since it makes upgrading the kernel very difficult. Changing the bootloader is a very dangerous procedure, and nominally one wants to perform that operation very rarely on a production board. The bit you quoted above describes other possible implementations, but not ours - I do agree the whole page needs to be re-written. All I'm worried about is giving people the impression that the kernel lives in the ROM, which is doesn't. - JordanCrouse (Talk to me!) 12:17, 6 December 2006 (EST)
- Thank you. That's much clearer.