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Coreboot port for 486 motherboard (UM8881/6)
- johnklos 2y agoIt's neat to see how people have been able to collect and save all sorts of information about older chipsets which makes projects like this possible. I've often wondered about how to re-solve certain problems now that we have decades of hindsight. For instance, your BIOS doesn't boot from CDs or from large disks. So what do we do? We make a disk image (vnd on BSD and whatever the equivalent on Linux make this so easy) and install an old fashioned BIOS boot block. We have a small 40 megabyte or so FAT-16 filesystem (FAT-32 wasn't a thing until 1996), on which we have a kernel, such as NetBSD because NetBSD can still run on 486 systems without fuss. The kernel, once loaded, knows how to access large disks, CDs, or even mount a filesystem over NFS. We then use that system to disklabel / fdisk the rest of the disk, format an FFS filesystem and swap, and install our OS. Simple, right? But how do we get this image on to an 80486 system? We really shouldn't lose to history the kinds of tools that let us boot from floppy. NetBSD still can, even though it takes something like six of them. Since the i80486 has no management engine, running an open source BIOS would make it fully, 100% open. Interesting... Will my next email server be an i80486 system? It's worth considering.
- snvzz 2y ago>Since the i80486 has no management engine, running an open source BIOS would make it fully, 100% open. Note there are fully open source RISC-V designs you can program into a FPGA that will yield higher performance than any 486 by orders of magnitude.
- transpute 2y agoWhat's an example FPGA for this purpose?
- buildbot 2y agoThis is one that you can use a fully open toolchain to build with: https://groupgets.com/products/orange-crab-85f-lattice-ecp5-fpga-development-kit?variant=39888044818617 https://groupgets.com/products/orange-crab-85f-lattice-ecp5-... Which you can build a RISCV core + linux for using: https://github.com/litex-hub/linux-on-litex-vexriscv https://github.com/litex-hub/linux-on-litex-vexriscv
- exe34 2y agoGoodness, this is cool! Do you have experience with this FPGA/toolchain? How long does it typically take to render something from Verilog to bitstream? E.g. a hello world adder v/s a risc v cpu?
- buildbot 2y agoI do! I’ve played around with it with this exact setup. It really depends on your processor, these toolchains really love a good mix of both high frequency and multi core. A hello world adder is less than a minute, a riscv core much much longer. A 16 core zen4/zen5 can compile the riscv core and linux in roughly 20 minutes? Compared to about an hour on a M1 Max macbook pro - It’s been awhile so I could be misremembering.
- deleted 2y ago[deleted]
- numpad0 2y agocan't you just have grub on PCI Option ROM or PXE from 66.104.*
- justsomehnguy 2y ago> Will my next email server be an i80486 system? It's worth considering. Nope. Anything crypto related (notably TLS transport) would not work or would be horrendously slow.
- johnklos 2y agoHave you tried it? ;) TLS on a 33 MHz m68030 is passable. Since the i80486 should be closer in performance to the m68040, negotiation could take place inside of the timeout that many servers would have. In some ways it would be a good rate limiter since you'd likely only want to allow a single connection at a time.
- ninjazee124 2y agoI am in awe of people who have the time for such projects!
- userbinator 2y agoLooking at the sizes and structure of the source alone, it is obvious that Coreboot is a product of the post-HLL average developoor, while in the 486 era BIOSes were exclusively written in very carefully optimised Asm. One naturally wonders what the latter could fit in the space of today's multiple-megabyte flash ROMs.
- winrid 2y agoNot sure what hell let loose has to do with anything...
- gjasny 2y agoMaybe HLL stands for “High Level Language”?
- winrid 2y agoAh, of course. I have never seen that abbreviation before.
- sixothree 2y agoFunny. I searched the term and found Hell Let Loose. Glad it was clarified because I never would have figured it out on my own. Also, incredible game worth checking out.
- AshamedCaptain 2y ago> while in the 486 era BIOSes were exclusively written in very carefully optimised Asm Nope; the change happened in the 386 era; by the 486 era most BIOSes would be (partially/mostly) written in a pretty uncarefully written "HLL". Even before I would argue against the "carefully optimized" ASM.
- userbinator 2y agoThey were written in Asm up into the 2000s; at least AMI and Award were. Despite a lot of macro use, there was certainly an emphasis on keeping things as small as possible. Contrast that with just shoving compiler output into the ROM image.