Adam Hunt wrote: > I have a few (read: a bunch) of questions regarding LinuxBIOS. Please bear > with me. > > I’m trying to get a clear sequence of events relating to a LinuxBIOS > facilitated boot primarily on x86 hardware (because that is what I am most > familiar with). > > Once the machine is powered on something reads whatever is in the > “BIOS” flash space and begins executing it. In this case it is > LinuxBIOS’s code to get into 32-bit protected mode and then initialize the > required hardware (i.e. DRAM, PCI controller, etc.). Then, the process continues on > with a Linux kernel (also stored in the flash/DoC). > > This is about where I lose track of what is going on…. Is the kernel > that was just loaded going to function as the kernel in the system once > booted? If so how difficult is it to upgrade the kernel in the field? If not
Yes. There is no difficulty to upgrade the kernel in the field. But it might be as "dagmerous" as "make bzlilo" for newbie users. > (and the kernel in the flash is used to “chain load” a second > kernel) isn’t that a bunch of extra work for nothing? > > Was there ever a boot loader like lilo or grub? Is there any way of > choosing between various kernels at boot? > Lilo and grub uses 16-bit BIOS calls. We do use etherboot to boot over LAN everyday. > If the “BIOS” flash/DoC was sufficiently large could it store an > entire minimal system (with a NFS mounted /usr and such)? > Yes, everybody in embeded LinuxBIOS business is doing that. > What is the purpose of using a DoC as apposed to a “classic” > flash device? > The asnwer is your last question. > What is/are the bottleneck(s) in regards to boot speed? > The speed of DoC/Flash. For DoC the max sustain read speed is about 600KB/s. A somewhat functional kernel, the size is about 800KB, which takes more than 1 sec to load. Beside, you still need to load some minimal application on the root disk. > Will LinuxBIOS play nicely with ACPI once implemented properly in kernel 2.6 > (or 3.0 as the case might be)? > If the AML interperter is build-in the kernel, I see no reason that ACPI can not be supported. We just need some utility as getpir to dump the ACPI tables. OT, what exactly is gmx.net ?? Some kind of ISP ?? I see a lot of people's mail address in gmx.net. Ollie
