RE: [PATCH v6 07/12] x86/head_32.S: Define start_cpu0
From: Yu, Fenghua
Date: Thu May 10 2012 - 16:48:37 EST
> -----Original Message-----
> From: H. Peter Anvin [mailto:hpa@xxxxxxxxx]
> Sent: Thursday, May 10, 2012 10:31 AM
> To: Yu, Fenghua; Ingo Molnar; Thomas Gleixner; Linus Torvalds; Andrew
> Morton; Mallick, Asit K; Luck, Tony; Arjan Dan De Ven; Siddha, Suresh B;
> Brown, Len; Srivatssa S. Bhat; Randy Dunlap; Chen Gong; linux-kernel;
> linux-pm; x86
> Subject: Re: [PATCH v6 07/12] x86/head_32.S: Define start_cpu0
> Can you check how this interacts with tip:x86/realmode?
When CPU0 is waken up by NMI, it's in protect mode and jumps to start_cpu0() which only sets up stack and goes to initial_code. CPU0 wake up doesn't go through trampline and starts from real mode. This is different from waking up AP when AP goes through INIT/STARTUP sequence and starts from real mode.