coreboot VS ExpansionCards

Why BIOS (did you mean UEFI?) when it runs the best boot loader, which is Coreboot¹. Many users would love to re-flash their bios/uefi for it, if it’s supported.

1: https://www.coreboot.org/

Coreboot is 0.6% C++.

NovaCustom ; some models come with Dasharo a coreboot distribution.

There may be other protections to restrict SPI flash access for security reasons (so you might not be able to flash your custom firmware in the OS), but worst case you can use a HW flasher (or maybe USB flashback). Still, this doesn't address the elephant in the room - platform initialization code might be open-sourced, but that isn't everything. You'll still need to figure out the board-specific stuff (the Super I/O chip, chipset GPIOs, other peripherals, etc.). Using coreboot as an example, Intel provides the Firmware Support Package blob to handle platform initialization. I think AGESA is somewhat similar to this, though Intel publicly releases the binaries for use in coreboot/etc. Thanks to the FSP, coreboot has support for recent Intel chipsets. However, there is only support for two recent consumer boards: the MSI PRO Z690-A WiFi DDR4 and DDR5.

coreboot/devicetree.cb at bcc9879151c0ff61dfa3f2206b538d5c8be619ba · coreboot/coreboot (github.com)

You usually can't take existing firmware and run it on a new CPU, because the new CPU requires different bringup code anyway. Take a look at https://github.com/coreboot/coreboot/tree/master/src/soc/int... to get some idea of how many different implementations there are for modern Intel alone (there's a bunch more for the pre-SoC style Intels). If you already have to port your firmware to a new CPU, you can deal with the CPU starting in a different mode - it is entirely an implementation detail that can be handled in the firmware.

NEM/CAR is used to avoid hacks like romcc. you need memory for a stack/etc if you want to run C code; romcc worked around this by compiling C code to asm that only used registers (no stack usage at all). this isn't needed if you can use NEM/CAR. either way I wouldn't say this massively reduces latency, since code is still being backed by SPI flash MMIO

Novacustom. Some models come with Dasharo an open source firmware based on coreboot.

It seems that Intel is currently 404ing the I remember in the 82579LM datasheet regarding firmware made a vague reference to the Intel ME being used the PXE boot. If the ME parition has neutered or the generated GBE partition is being used, this shouldn't be a concern.

Coreboot/Libreboot (recently merged with OSboot, so presumably that means the policy problems have been fixed) as far as I know do not benefit from any such standardization and often have to resort to reverse-engineering.

There are many laptops and desktops that fit the bill.

Frame.work: https://frame.work/

Dell: https://www.dell.com/support/kbdoc/en-us/000138246/linux-on-...

System76: https://system76.com/laptops

Kubuntu Focus: https://kfocus.org/land/business

I am sure there are more, this is only what I have found in less than 5 minutes of searching.

Idk, I just followed the instructions and it works. I did it on my frame.work laptop and on my 10 year old desktop made out of literal trash and it works fine in both cases.

I bought a Framework Laptop a few months ago. I was really drawn to the idea of a laptop that I could customize and which was built with repairability in mind. That's a really great stance to take, and it didn't hurt that the laptop build and specs looked good, so I went for it. It was also cool that I could buy it with no memory, no hard drive, no power adapter, and no operating system, and supply those things separately. In general I was very happy with it, but it had one little behavior that bugged me. This is a long journey, but I hope it contains some useful information.

a small startup currently focusing on upgradeable laptops, see https://frame.work

I looked at frame.work, but I don't want to preorder in a batch. So, I think we're looking in the right areas and I wouldn't stray into other brands because nothing tops the XPS build quality.

Honestly if gaming is not much of a concern and you are happy to upgrade in 2-3 years again, MacBook Air will be fine. But if you have that much money to spend I’d recommend framework laptops. Since even iGPUs these days can handle most CAD software as long as it’s not too heavy project work and rendering etc. plus framework gives great upgrade pathway. https://frame.work

Honestly the only laptop I've seen that i would personally buy is the framework laptop especially with the 16" one coming soon with a GPU. Not a great choice for OP though since the 16" is still a few months from release iirc.

Framework has frame.work, its own forums, and other ways to communicate to its customers and base.