svn commit: r326203 - head/sys/conf

[Nathan Whitehorn]

On 11/28/17 08:23, Justin Hibbits wrote:
> On Tue, Nov 28, 2017 at 10:13 AM, Nathan Whitehorn
> <nwhitehorn at freebsd.org> wrote:
>>
>> On 11/28/17 07:27, Justin Hibbits wrote:
>>> On Sat, Nov 25, 2017 at 3:45 PM, Nathan Whitehorn
>>> <nwhitehorn at freebsd.org> wrote:
>>>> Author: nwhitehorn
>>>> Date: Sat Nov 25 21:45:51 2017
>>>> New Revision: 326203
>>>> URL: https://svnweb.freebsd.org/changeset/base/326203
>>>>
>>>> Log:
>>>>     Avoid emitting a PT_INTERP section for powerpc64 kernels and arrange
>>>> for
>>>>     the first instruction to be at the start of the text segment. This
>>>> allows
>>>>     the kernel to be booted correctly by stock kexec-lite.
>>>>
>>>>     MFC after:    2 weeks
>>>>
>>>> Modified:
>>>>     head/sys/conf/ldscript.powerpc64
>>>>
>>>> Modified: head/sys/conf/ldscript.powerpc64
>>>>
>>>> ==============================================================================
>>>> --- head/sys/conf/ldscript.powerpc64    Sat Nov 25 21:44:23 2017
>>>> (r326202)
>>>> +++ head/sys/conf/ldscript.powerpc64    Sat Nov 25 21:45:51 2017
>>>> (r326203)
>>>> @@ -10,7 +10,7 @@ SECTIONS
>>>>    {
>>>>      /* Read-only sections, merged into text segment: */
>>>>
>>>> -  . = kernbase + SIZEOF_HEADERS;
>>>> +  . = kernbase;
>>>>      PROVIDE (begin = . - SIZEOF_HEADERS);
>>>>
>>>>      .text      :
>>>> @@ -24,7 +24,10 @@ SECTIONS
>>>>      _etext = .;
>>>>      PROVIDE (etext = .);
>>>>
>>>> -  .interp     : { *(.interp)   }
>>>> +  /* Do not emit PT_INTERP section, which confuses some loaders
>>>> (kexec-lite) */
>>>> +  .interpX    : { *(.interp)   } : NONE
>>>> +  /DISCARD/   : { *(.interp)   }
>>>> +
>>>>      .hash          : { *(.hash)          }
>>>>      .dynsym        : { *(.dynsym)                }
>>>>      .dynstr        : { *(.dynstr)                }
>>>>
>>> This broke powerpc64 Book-E kernels.  It now puts a 1MB blank space
>>> ahead of the kernel data (ELF header + 1MB - sizeof(header) of 0's),
>>> meaning that now the kernel needs to be loaded by uboot 1MB earlier in
>>> memory, rather than straight on the 64MB boundary as it has been.
>>>
>>> - Justin
>>>
>> How on Earth? It doesn't do that on my system. What binutils are you using?
>> -Nathan
>>
> This is using base binutils (2.17.50...)  I don't know why it's doing
> this, but readelf shows that file offset 0x0000000000100000 maps to
> 0xc000000000000000, and it goes from there.
>
> - Justin
>

Bizarre. Why don't you just revert for now (I need to run) and I can 
figure out what went wrong later?
-Nathan