ARM Context ID Register & Process Context Switch

Hi, all

What is the content of Context ID Register of ARM Cortex A9. Is it OS that is responsible for assigning the value

of Process ID and ASID? As far as I know, it is so in Linux. Is that the same in the other OSes?

Is it essential to deal with ASID if I want to make context switch correctly? Does Cortex A8 have no Context ID

Register? Minix's process context switch running on a Cortex A8 core doesn't cope with ASID when it writes

TTBR.

Thank you.

Best Regards,

Channing M.

Parents
  • The corresponding identifier for x86 is called PCID - process context id, so that's the thing to look for in the x86 Minix code as implementing the business isn't entirely straightforward. I get the feeling it will be much more worthwhile on Minix 3 than it ever has been with Linux because of it switching processes for every little service or driver interrupt, so yeah go for it.

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  • The corresponding identifier for x86 is called PCID - process context id, so that's the thing to look for in the x86 Minix code as implementing the business isn't entirely straightforward. I get the feeling it will be much more worthwhile on Minix 3 than it ever has been with Linux because of it switching processes for every little service or driver interrupt, so yeah go for it.

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