Thiemo Seufer wrote:
> Franck Bui-Huu wrote:
>> Thiemo Seufer wrote:
>>> Franck Bui-Huu wrote:
>>>> - if (CPHYSADDR(initrd_end) > PFN_PHYS(max_low_pfn)) {
>>>> + if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
>>> ISTR this failed on O2, where kernel+initrd are loaded into KSEG0 but the
>>> PAGE_OFFSET is for XKPHYS.
>>>
>> I guess that you were meaning somthing like:
>>
>> LOADADDR = 0xffffffff80004000
>> PAGE_OFFSET = 0xa800000000000000
>>
>> is that correct ?
>
> Yes.
>
>> If so could you explain the choice of these values
>> because I fail to understand it.
>
> It allows to load a 64-bit kernel in KSEG0,
sorry to be ignorant of 64 bit kernels, but what's the point
to load them in KSEG0.
> and use short 2-instruction symbol references there.
do you mean "it allows to use only 2 'lui' instructions to load
a symbol address into a register" ?
Futhermore I don't see how some part of the kernel convert virtual
address into a physical one with such values. For example in setup.c,
the function resource_init() does:
code_resource.start = virt_to_phys(&_text);
code_resource.end = virt_to_phys(&_etext) - 1;
data_resource.start = virt_to_phys(&_etext);
data_resource.end = virt_to_phys(&_edata) - 1;
How does it work in this case ?
Thanks
Franck
