On 9/26/19 12:58 AM, [email protected] wrote: > On September 26, 2019 12:55:51 AM PDT, Cao jin <[email protected]> > wrote: >> On 9/26/19 2:01 PM, Ingo Molnar wrote: >>> * Cao jin <[email protected]> wrote: >>> >>>> The fields marked with (reloc) actually are not dedicated for >> writing, >>>> but communicating info for relocatable kernel with boot loaders. For >>>> example: >>>> >>>> ============ ============ >>>> Field name: pref_address >>>> Type: read (reloc) >>>> Offset/size: 0x258/8 >>>> Protocol: 2.10+ >>>> ============ ============ >>>> >>>> ============ ======================== >>>> Field name: code32_start >>>> Type: modify (optional, reloc) >>>> Offset/size: 0x214/4 >>>> Protocol: 2.00+ >>>> ============ ======================== >>>> >>>> Signed-off-by: Cao jin <[email protected]> >>>> --- >>>> Unless I have incorrect non-native understanding for "fill in", I >> think >>>> this is inaccurate. >>>> >>>> Documentation/x86/boot.rst | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst >>>> index 08a2f100c0e6..a611bf04492d 100644 >>>> --- a/Documentation/x86/boot.rst >>>> +++ b/Documentation/x86/boot.rst >>>> @@ -243,7 +243,7 @@ bootloader ("modify"). >>>> >>>> All general purpose boot loaders should write the fields marked >>>> (obligatory). Boot loaders who want to load the kernel at a >>>> -nonstandard address should fill in the fields marked (reloc); other >>>> +nonstandard address should consult with the fields marked (reloc); >> other >>>> boot loaders can ignore those fields. >>>> >>>> The byte order of all fields is littleendian (this is x86, after >> all.) >>> >>> Well, this documentation is written from the point of view of a >>> *bootloader*, not the kernel. So the 'fill in' says that the >> bootloader >>> should write those fields - which is correct, right? >>> >> >> Take pref_address or relocatable_kernel for example, they have type: >> read (reloc), does boot loader need to write them? I don't see grub >> does >> this at least. > > Read means the boot later reads them.
is that boot loader ?? -- ~Randy
