[U-Boot] relocation problem on powerpc

[Joakim Tjernlund]

Joakim Tjernlund/Transmode wrote on 2014/09/09 14:30:13:

> From: Joakim Tjernlund/Transmode
> To: 
> Cc: Chris Packham <judge.packham at gmail.com>, u-boot 
<u-boot at lists.denx.de>
> Date: 2014/09/09 14:30
> Subject: Re: [U-Boot] relocation problem on powerpc
> 
> 
> > > Here's some more info from a build without any of my modifications.
> > > 
> > >   $ git describe
> > >   v2014.10-rc2-12-g0b703db
> > > 
> > >   $ powerpc-e500-linux-gnu-gcc --version
> > >   powerpc-e500-linux-gnu-gcc (Gentoo 4.6.3-r1 p1.9, pie-0.5.2) 4.6.3
> > > 
> > >   $ grep '_GOT2_TABLE_\|_GLOBAL_OFFSET_TABLE_\|__got2_entries' 
u-boot.map
> > >   0x00000000effb5100                _GOT2_TABLE_ = .
> > >   0x00000000effb7d38                _GLOBAL_OFFSET_TABLE_
> > >   0x00000000effb7d48                PROVIDE (_GLOBAL_OFFSET_TABLE_, 
(. + 0x4))
> > >   0x0000000000000b0d                __got2_entries =
> > > (((_GLOBAL_OFFSET_TABLE_ - _GOT2_TABLE_) >> 0x2) - 0x1)
> > > 
> > >   $ gdb-multiarch u-boot
> > >   (gdb) disassemble /r 0xeffb5100,0xeffb7d48
> > >   Dump of assembler code from 0xeffb5100 to 0xeffb7d48:
> > >      0xeffb5100 <_GOT2_TABLE_+0>: ef fb 51 00     .long 0xeffb5100
> > >      0xeffb5104 <_GOT2_TABLE_+4>: ef fb 7d 44     dtstsf cr7,f27,f15
> > >      0xeffb5108 <_GOT2_TABLE_+8>: ef f4 00 00     .long 0xeff40000
> > >      0xeffb510c <_GOT2_TABLE_+12>:        ef f4 01 00     .long 
0xeff40100
> > >     <snip>
> > >      0xeffb7d30 <_GOT2_TABLE_+11312>:     ef f6 6e 74     .long 
0xeff66e74
> > >      0xeffb7d34 <_GOT2_TABLE_+11316>:     f0 00 00 d0     psq_st 
f0,208(r0),0,0
> > >      0xeffb7d38 <_GLOBAL_OFFSET_TABLE_+0>:        00 00 00 00 .long 
0x0
> > >      0xeffb7d3c <_GLOBAL_OFFSET_TABLE_+4>:        00 00 00 00 .long 
0x0
> > >      0xeffb7d40 <_GLOBAL_OFFSET_TABLE_+8>:        00 00 00 00 .long 
0x0
> > >      0xeffb7d44 <_FIXUP_TABLE_+0>:        ef fb 99 d4     .long 
0xeffb99d4
> > > 
> > > So no there is no brlr at the end of the table.
> > 
> > There should be, see 
http://www.freescale.com/files/32bit/doc/ref_manual/E500ABIUG.pdf, chap 
4.3.2
> 
> So I did a quick test too with my copy of u-boot:
> (gdb) disass /r 0x00000000effa0a48,0x00000000effa0a68
>    Dump of assembler code from 0xeffa0a48 to 0xeffa0a68:
>    0xeffa0a48 <_GOT2_TABLE_+9800>: f0 00 00 dc .long 0xf00000dc
>    0xeffa0a4c <_GOT2_TABLE_+9804>: ef f6 29 48 .long 0xeff62948
>    0xeffa0a50 <_GOT2_TABLE_+9808>: f0 00 00 e0 .long 0xf00000e0
>    0xeffa0a54 <_GOT2_TABLE_+9812>: 4e 80 00 21 blrl
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>    0xeffa0a58 <_GLOBAL_OFFSET_TABLE_+0>: 00 00 00 00 .long 0x0
>    0xeffa0a5c <_GLOBAL_OFFSET_TABLE_+4>: 00 00 00 00 .long 0x0
>    0xeffa0a60 <_GLOBAL_OFFSET_TABLE_+8>: 00 00 00 00 .long 0x0
>    0xeffa0a64 <_FIXUP_TABLE_+0>: ef fa 23 1c .long 0xeffa231c

> $ powerpc-softfloat_4.5.3-linux-gnu-ld --version
> GNU ld (GNU Binutils) 2.21.1
> 
> I don't know it this is tool(ld) problem or if something in u-boot's 
build env. Try dropping
> --gc-sections, see if that changes anything, or add --bss-plt or similar

--bss-plt seems to be the answer:
http://lists.denx.de/pipermail/u-boot/2014-February/173134.html

  Jocke