For example, look at all of the legacy stuff in an x86 system. You have the strange structure of the interrupt descriptor table/global descriptor table. You have the good old Intel 8042 keyboard controller, Intel 8259 programmable interrupt controller, old-style programmable interval timer, A20 gate and so much more.
There's so much legacy baggage inherent in the x86 architecture, all because of software compatibility. (ROM-BASIC will still run on a modern PC!)
ARM on the other hand has less to really worry about, sure there's some legacy infrastructure, such as the ARM vector table. Modern ARM architectures such as ARMv8-A remove old legacy baggage in favor of completely renovating it. (Look at the old coprocessor interface for instance. In A64 mode, it is completely gone. You must use 'mrs/msr' instructions compared to 'mrc/mcr'). There's also far less legacy software to worry about.
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I just wish more people dealt with ARM instead of x86. It's a far better architecture for people to learn system design.
Why?
(I'm curious as I know little of these kinds of things, and because citing sources or giving arguments is always a good thing)
For example, look at all of the legacy stuff in an x86 system. You have the strange structure of the interrupt descriptor table/global descriptor table. You have the good old Intel 8042 keyboard controller, Intel 8259 programmable interrupt controller, old-style programmable interval timer, A20 gate and so much more.
There's so much legacy baggage inherent in the x86 architecture, all because of software compatibility. (ROM-BASIC will still run on a modern PC!)
ARM on the other hand has less to really worry about, sure there's some legacy infrastructure, such as the ARM vector table. Modern ARM architectures such as ARMv8-A remove old legacy baggage in favor of completely renovating it. (Look at the old coprocessor interface for instance. In A64 mode, it is completely gone. You must use 'mrs/msr' instructions compared to 'mrc/mcr'). There's also far less legacy software to worry about.
I've been looking for good OS dev tutorials for ARM. Does anyone know of any besides Baking Pi?
My research about 12months ago didn't give much, sadly.