March 1999 - OpenBIOS - mail.coreboot.org

Making a BIOS on my own...
by Niklas Ekström March 8, 1999

March 8, 1999

Hi everyone, I just thought I'd post a note on way I've decided to work on a BIOS of my own. The main reason is that we are getting no where. It's not that I don't want to be a part of OpenBIOS, rather on the contrary. But every time I come up with some suggestion, atleast a couple of people will point of how wrong I am, and the result is that we stand still. I find this very frustration, since I feel that we should act now so we can have working BIOS in half a year or so. No one will be happy by us sitting here arguing without reaching anywhere. The greatest problem I see is that we have no real (active) leader, that could take decissions for us and say that this is how we are going to do it, now move!. If things start to move around here later in, I would like to help out, but until then I will go ahead and make a BIOS of my own. If someone happens to agree with my ideas of what a BIOS should be like (should be pretty obvious from my previous posts), feel free to contact me on the above email address. / Niklas

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Clarification....
by Dave March 8, 1999

March 8, 1999

After reading the responses to my "Philosophical question" it became clear to me that what I was suggesting is more of a boot loader than a bios. I still think this is a good approach. Separate the BIOS functionality (standard interface to the hardware) from the boot loader. The reasoning behind separating the two is that 1) a good BIOS would be as much OS dependent as it is hardware dependent. 2) Modern operating systems do not currently take advantage of the services provided by the BIOS. For an operating system that comes with its own drivers (that work directly with the hardware) there is little or no need for a BIOS that provides API's to the hardware. The only need for a so called BIOS is to initialize the hardware to the point that it can read from the boot device and load the OS (or an OS loader) into memory. For legacy OS's (Dos, Windows) that require a BIOS, the Boot Loader can load a BIOS from the boot device directly into Shadow Ram and execute it as if it where copied from EEPROM to Shadow Ram. What I am thinking is something along the lines of a layered approach. * Boot loader only * - Linux kernel could be loaded this way --------------------------------------- Media: EEPROM BootDevice Code: BootLoader -> OS * Boot Loader & OS loader * - Lilo (modified?) could be used this way ----------------------------------------- Media: EEPROM BootDevice Any Device Code: BootLoader -> OSloader -> OS * BootLoader, BIOS and Legacy OS * - Loads BIOS code from boot device to Shadow, runs BIOS code (from Shadow) which then boots legacy OS (such as DOS, Windows etc). ---------------------------------------------- Media: EEPROM BootDevice BootDevice Code: BootLoader -> BIOS -> OS * Boot Loader, BIOS, (Legacy OS support) and OSloader * - Used on a system where multiple OS's must be supported. BootLoader loads BIOS into Shadow, BIOS loads OS loader which can be used to select which OS will be loaded. --------------------------------------------------------- Media: EEPROM BootDevice BootDevice Any Device Code: BootLoader -> BIOS -> OSloader -> OS I guess my thinking here is that a boot loader will be a much simpler piece of code to implement than a full scale BIOS. The first generation development efforts would focus on providing good boot support for various boot devices without the added burden of replicating (or inventing new) BIOS API's. During development we could use the copy of the BIOS that comes with all motherboards (moving it to an image on disk) for legacy OS support. Once the Boot Loader library and the tools needed to create a good OpenBIOS boot EEPROM are working, efforts can be expanded to creating an open BIOS clone for legacy OS support (assuming there is still demand for such a thing). There is a good chance that M$ would make future versions of Windows (when/if they abandon legacy DOS support) boot without a BIOS if the open BIOS boot loader works well enough. Everyone wants to save a buck and if a BIOS is not needed, I am sure the motherboard makers will be happy to ditch it in favor of a smaller, free, OpenBIOS boot PROM. In the end there may no longer be a need for the BIOS as we know it. Then again we could take the path to create a new and improved BIOS model that would be good enough to actually be used by modern OS's and motherboard makers. But for that to happen we would have to gain some credibility in the greater world by producing something that works and is widely accepted. Creating a library of boot code (and a system for managing and configuring it for various hardware platforms) will be a significant challenge given the number of possible motherboards and boot devices there are out there. I propose that OpenBIOS boot code would be a good first step goal for a modular open BIOS project. Thoughts, comments? Dave PS. A couple of you have mentioned Open Boot. Where can I find out more about it? Is Open Boot open as in open source or open as in marketing-buzzword "open". Could this be used as the boot loader part of the project? Is it something that we could build on?

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OFFTOPIC: New MBR and partitioning standard?
by Dave Cinege March 6, 1999

March 6, 1999

Isn't it about time the x86 platform supported more then 4 'real' partitions? I'm getting really sick of this limitation and was thinking of sitting down with some peers, drafting a new extended MBR standard, then submitting it OS vendors. For instance, the first partition is (generally) started on the 65th sector. That leaves 63 512byte sectors that are always free. Why not extend the normal partition entires say 16 sectors (== about 512 16byte partition entires), and reserve the remaining sectors for extended MBR code? (IE the code in sector 0, hops to sector 18) This would be very easy to implement and remain compatible with legacy OS's. A boot manager (partition entry swapper) program could be used to move 'extended' entries in and out of the original sector 0 partition table for the sake of further legacy OS compatibility. Has any one ever attempted to have something like this implemented by OS vendors? Any comments you'd like to make? (Please via private mail) I'd like to get some initial response back on this idea, and if it is positive I'll set up a mailing list/and or have some IRC meetings to discuss details. -- http://www.linkscape.net/ Linkscape Internet Services 732-541-4214 http://www.linuxrouter.org/ Linux Router Project At 19981216.11:59 Zulu, Mach 1 was broken with a 1.0080162GHz Dual CPU machine. I'm the Degenerate Overclocker that did it. http://www.psychosis.com/doa/

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