Bug#720272: unbootable and lead to data loss?
On Wed, Aug 21, 2013 at 11:11:21AM +0100, Ben Hutchings wrote:
> There might be if the CPUs that don't advertise PAE also weren't tested
> for PAE functionality at manufacturing time.
Does the spec for this cpu family mandate the check in CPUID?
Well I checked and it tells:
| Software can discover support for different paging features using the
| CPUID instruction:
| PAE: physical-address extension.
| If CPUID.01H:EDX.PAE [bit 6] = 1, CR4.PAE may be set to 1, enabling PAE
| paging (this setting is also required for IA-32e paging).
So it is not mandatory.
Other parts are more specific, for example:
| (Processors that do not support CPUID function 80000001H do not allow
| IA32_EFER.NXE to be set to 1.)
Bastian
--
Vulcans never bluff.
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