Post B0mqTUS2ZyZ3XDf7Ts by lymenzies@fosstodon.org
(DIR) More posts by lymenzies@fosstodon.org
(DIR) Post #B0mqTSwoAbzGs42fA0 by Toxic_Flange@infosec.exchange
2025-11-30T19:14:52Z
0 likes, 0 repeats
So I had a silly thought.. Could you use a modern day CPU with no extra ram at all today? What about without a hard drive for an OS?So at the start the OS was on a ROM chip, did that double at the equiv of a bios?Modern CPUs have more cache than PC's needed of yesteryear. UEFI BIOS are massive in size, and with the existence of Coreboot and its ability to have nearly anything for a payload, linux, seabios, etc you could put a very small OS on there (by today's standards). I'm sure someone's tried or done something along these lines right?EDIT: I was thinking just x86_64 CPUs but my examples draw from things like C64/Atari/Amiga/ etc computers too. So any modern cpu today that could run a small OS that lets people just work on stuff. Like with no extra or minimal extra chips for some bare minimum IO#moderncomputing #computer #computerscience #retrocomputing #thoughtexperiment
(DIR) Post #B0mqTUS2ZyZ3XDf7Ts by lymenzies@fosstodon.org
2025-11-30T19:23:42Z
0 likes, 0 repeats
@Toxic_Flange Depends on what you mean by modern day CPU. A lot of ARM chips have XIP mode and ram on die.Or are you talking about x86_64 only?
(DIR) Post #B0mqTV2uMu3TNYuYwi by Toxic_Flange@infosec.exchange
2025-11-30T19:25:11Z
0 likes, 0 repeats
@lymenzies I was thinking about x86_64, but yeah I think to expand this to be fair, ARM would be quite acceptable in this case.
(DIR) Post #B0mqTVdm9pXtDuA0PY by lymenzies@fosstodon.org
2025-11-30T19:54:45Z
0 likes, 0 repeats
@Toxic_Flange I don't know anything about this subject, but it looks like this was once a feature of CoreBoot but required a proprietary blob. https://www.phoronix.com/news/Coreboot-FSP-T-Not-NeededThe keyword to look for is cache-as-ram.
(DIR) Post #B0mqTWUazRnRrisBk0 by Toxic_Flange@infosec.exchange
2025-11-30T20:06:56Z
0 likes, 0 repeats
@lymenzies Ohh, thanks! turns out i've completely forgot about embedded system-on-chip type deals as well which brings us closer to what I was asking about. What this really highlights is i need to learn how the modern uefi based systems boots today.
(DIR) Post #B0mqTXDGJNWe6FlrMW by tomjennings@tldr.nettime.org
2025-11-30T23:47:00Z
0 likes, 0 repeats
@Toxic_FlangeThe ARM chip used in Teensy 4.1 has a meg of memory, lots of flash etc, 600 mhz. USB support and all that. There's lots of chips like this now. @lymenzies