Re: [PATCH 4/4] Add cpu_number and cpuboot

[Jessica Clarke]

On 25 Jan 2023, at 06:27, Flávio Cruz <flaviocruz@gmail.com> wrote:
>> On Tue, Jan 24, 2023 at 2:54 AM Samuel Thibault <samuel.thibault@gnu.org> 
>> wrote:
>> Flávio Cruz, le mar. 24 janv. 2023 01:15:15 -0500, a ecrit:
>> >     +       int kernel_id;
>> >     +       unsigned long flags;
>> >     +
>> >     +       cpu_intr_save(&flags);
>> >     +
>> >     +       kernel_id = apic_get_cpu_kernel_id(apic_get_current_cpu());
>> >     +
>> >     +       cpu_intr_restore(flags);
>> >     +
>> >     +       return kernel_id;
>> > 
>> > 
>> > Might be unrelated to this change, but will this be portable for x86_64? It
>> > seems we either should use uint32_t to store EFLAGS or use pushfq/popfq to 
>> > get
>> > RFLAGS instead.
>> 
>> cpu_get_eflags will already use pushfq/popfq, won't it? (since it takes
>> the unsigned long output parameter.
> 
> I tried it in compiler explorer and it shows we have to use pushfq 
> explicitly: https://godbolt.org/z/MYjPaEh31

Not sure what you’re trying to show? pushf assembles to the same thing as 
pushfq.

Jess

>> Samuel