[coreboot] [PATCH] flush CPU queue when PE set 0

Kevin O'Connor kevin at koconnor.net
Tue Apr 14 00:37:44 CEST 2009


On Tue, Apr 14, 2009 at 12:05:23AM +0200, Rudolf Marek wrote:
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> Hello
> 
> Following patch flushes the instruction queue when we set PE=0. This is normally
> done by FAR JMP, but here it is more tricky because we run at EIP>1MB. Many
> thanks to Marc and Kevin to tell me how to fix it
> 
> The trick is to use 0x66 prefix (done with ljmpl) it will allow to jump in real
> mode to any EIP addresses ;)

FYI - "ljmpl" is just ATT syntax for "far jmp".

-Kevin




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