ARM is great, ARM is terrible, and so is RISC-V
changelog.complete.org46 points by edward 12 hours ago
46 points by edward 12 hours ago
It's incredible how in 2025 people still don't grasp what a system on a chip is [1], and that the CPU cores are just a small part of the whole. Your operating system is barely concerned about the instruction set, and much more concerned about the buses and so on that are available, and how to drive them.
You only get standardization in servers because relatively speaking the number of peripheral types on the server SoC is smaller, and their usage modes more predictable.
I would say part of it is that ARM never really had wide spread socketed chips. It's pretty much just always a soldered highly integrated unit.
Go go back far enough you had a point in time for example you could swap an Intel or AMD cpu onto the same motherboard. Also using expansion cards for additional hardware capability was the norm. So software kinda evolved to handle disparate configurations of hardware.
ARM evolved differently. It end up being to be used more in embeded and then SoC systems. Hardware around the CPU and later on Die ended up with often a unique configure for the system/device. So the need to handle disparate hardware configurations was less important. Also the way ARM licenses their IP definitely pushed things to be more like this.
RISC-V atm is often being used in place of ARM so a lot entities are kinda are treating similar to ARM when developing a system/device. However, RISC-V since it's an open license on the ISA does not have to be used in similar way. Like imagine if there was some standardized socket for RISC-V chips and that took off, we would probably see things like UEFI and drivers/kernel drivers meant to work with more than just one single configuration of hardware ect...
> You only get standardization in servers because relatively speaking the number of peripheral types on the server SoC is smaller, and their usage modes more predictable.
You get standardization on servers because of UEFI and ACPI. There are some ARM boards out there with UEFI, but for whatever reason it hasn't generally caught on in the ARM world like it has for x86.
> It's incredible how in 2025 people still don't grasp what a system on a chip is [1], and that the CPU cores are just a small part of the whole.
Many people are only casually interested in something, so they learn less quickly. Or they are just learning for the first time. It's not actually particularly incredible that there are people who don't know this.
The author appears to be nostalgic for the wintel monopoly that made it possible to write software for one system standard "PC" and have it run on dozens of different manufacturer's hardware. The people who use ARM chips typically write their own code because they aren't building general purpose computers, they are building an appliance of some sort, whether its a phone or an access point or a disk controller.
I don't disagree at all with you, but it does pain me a little bit to see a phone referred to as an appliance. Phones nowadays are plenty capable general purpose computers if they aren't intentionally handicapped by the manufacturers, and the manufacturers certainly do think of them as appliances and treat them as such, but I wish that collectively we would reject that and insist on not artificially hobbling their capabilities
I know it feels like a semantic quibble. Consider that you can boot and run Linux on the processor that powers a Seagate hard drive. You can even run a c compiler and develop new code on it. But when you pull one from its protective wrapping after you bought it from a distributor, it isn't a "computer", it's a storage device (dedicated function, aka an appliance for storing data), that you can plug into a general purpose computer, or into a smart television, or into a DVR, Etc.
Similarly, for a long time, the CPU in my washing machine (a Z80) was the same processor that my first computer with disk drives had (a Cromemco System 3, aka a "business computer" which ran CP/M) but it was intentionally hobbled to just run the display, run some timed processes, and read various sensors.
Building "purpose built systems" that happen to have a computer processor inside of them because it is cheaper or more efficient to implement their functions in code, are what pretty much everyone considers "appliances." Sometimes obviously so, as in washing machines, and sometimes not so obviously when you can buy "apps", or "personality modules", or "game cartridges" for them to make them do something useful given the constraints of the fixed I/O they have.
But if you have a computer system that is intentionally hobbled to a fixed set of things, then for me, it's an appliance and certainly not a general purpose computer.
The author is specifically talking about Raspberry Pi upstreaming changes. Isn't that about as close as you will get to a general purpose SoC?
Right, and to emphasise the point there are x86 machines which are not architecturally PCs, such as the original XBox and Playstations 4 and 5.
You don’t need a license to build and sell a RISC-V chip. I believe that is its primary advantage over ARM. Anything more is gravy :)
Vendors don't need to ship their own images at all. Just let users install stock Debian, then provide a thin vendor package set (kernel, u-boot, DTBs, firmware) tied together by a meta-package. With apt pinning, upgrades become normal Debian transactions, security updates track Debian, and the vendor layer shrinks to a small LTS kernel delta plus boot bits.
> Raspberry Pi OS is only based on Debian bookworm (released in 2023) and very explicitly does not support a key Debian feature: you can’t upgrade from one Raspberry Pi OS release to the next, so it’s a complete reinstall every 2 years instead of just an upgrade.
What? I've upgraded my RPis in-place every single time there's a new OS release. They don't support upgrading that way, perhaps, but I've never had a problem.
And even for official Debian releases, they recommend you do a full backup, because it might not work.
Been here for a few years already honestly. I've found Raspis kind of annoying to deal with, and x86 mini PCs a lot more consistent and reliable.
Still holding out hope for RISC-V though, my little Milk-V pico-size Ubuntu boards are pretty cool, and I'd much rather write Linux code than rp2040 code directly (because I'm not an embedded developer and don't really know what I'm doing lol)