question about boot_params global variables

jim.cromie at gmail.com jim.cromie at gmail.com
Sun Nov 20 12:46:06 EST 2022


On Mon, Nov 14, 2022 at 11:41 AM Saad Masood <saadahmed42 at gmail.com> wrote:
>
> Hi Jim,
>     In C, two global variables with the same name are converted to one global variable (same memory address space).   So, the same variable is referenced with or without the 'extern' keyword.
>
> Thanks,
>
>

thanks Saad,

its nice when a thread reaches a tight conclusion.


>
> Saad
>
> On Mon, Nov 14, 2022 at 11:23 AM <jim.cromie at gmail.com> wrote:
>>
>> On Tue, Aug 16, 2022 at 4:10 AM shiyu chou <shiyu2010310 at gmail.com> wrote:
>> >
>> > Hello all:
>> > In arch x86 directory I found two global variables with the same name(master branch):
>> > 1.arch/x86/boot/main.c
>> > near line 18: struct boot_params boot_params __attribute__((aligned(16)));
>> > 2.arch/x86/kernel/setup.c
>> > near line 75: struct boot_params boot_params;
>> > Is that wrong to define two global variables with the same name? And when use extern to reference the variable,which one did it reference?
>> >
>>
>> hi, did you figure out a satisfactory answer ?
>>
>> what happens when you build with W=1 ?
>>
>>
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