system-clang (elfv2) and devel/binutil at powerpc (32-bit): booting fail very early on PowerMac3,6 example ; also build problem why I tried this

[Mark Millard]

(There are later notes below with build failure
information that lead me to try devel/binutils at powerpc .)

Because of the (cross-)build failure (from amd64):

--- acl_nfs4.ko.full ---
ld: acl_nfs4.kld(.text+0x234): R_PPC_PLTREL24 reloc against local symbol
acl_nfs4.kld: could not read symbols: Bad value
*** [acl_nfs4.ko.full] Error code 1

when using the default ld for 32-bit powerpc, I
tried using devel/binutil at powerpc for which
buildworld buildkernel at least ran to completion.
The build was of a non-debug kernel (and world),
but with symbols.

But the result failed to boot, stopping very early:
(typed from a image)

. . .
Booted from: /pci at f4000000/ata-6 at d/disk at 0

Loading /boot/defaults/loader.conf
/boot/kernel/kernel data=0xd97874+0x2ebdd4 syms=[0x4+0x97740+0x4+0xc34d2]

Invalid memory access at   %SRR0: 04C00000   %SRR1: c0000000

Apple PowerMac3,6 4.6.0f1 BootROM built on 02/20/03 at 13:52:27
. . .




As for the build failure . . .


# Meta data file /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/powerpc.powerpc/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/acl_nfs4/acl_nfs4.kld.meta
CMD ld -m elf32ppc_fbsd --secure-plt -d -warn-common  -r -d  -o acl_nfs4.kld subr_acl_nfs4.o
CMD ctfmerge -L VERSION -g -o acl_nfs4.kld subr_acl_nfs4.o
CMD :> export_syms
CMD awk -f /usr/src/sys/conf/kmod_syms.awk acl_nfs4.kld  export_syms | xargs -J% objcopy % acl_nfs4.kld
CWD /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/powerpc.powerpc/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/acl_nfs4
TARGET acl_nfs4.kld
. . .



From readelf -a for the subr_acl_nfs4.o :
(acl_nfs4_sync_mode_from_acl is GLOBAL here)

. . .
Relocation section with addend (.rela.text):
r_offset r_info   r_type              st_value st_name + r_addend
00000076 000014fc <unknown: 0xfc>     00000000 .got2 + 8022
0000007a 000014fa <unknown: 0xfa>     00000000 .got2 + 8026
000001ac 00003112 R_PPC_PLTREL24      00000000 groupmember + 8000
00000234 00003012 R_PPC_PLTREL24      00000458 acl_nfs4_sync_mode_from_acl + 8000
000002c4 00003312 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
000002f4 00003312 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
0000032c 00003312 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
00000360 00003312 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
0000038c 00003312 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
000007c6 000014fc <unknown: 0xfc>     00000000 .got2 + 800a
000007ca 000014fa <unknown: 0xfa>     00000000 .got2 + 800e
00001026 000014fc <unknown: 0xfc>     00000000 .got2 + 8006
0000102a 000014fa <unknown: 0xfa>     00000000 .got2 + 800a
00001676 000014fc <unknown: 0xfc>     00000000 .got2 + 800a
0000167a 000014fa <unknown: 0xfa>     00000000 .got2 + 800e
00001698 00002a12 R_PPC_PLTREL24      00000000 acl_alloc + 8000
000016a8 00003012 R_PPC_PLTREL24      00000458 acl_nfs4_sync_mode_from_acl + 8000
00001748 00002b12 R_PPC_PLTREL24      00000000 acl_free + 8000
000017e8 00002b12 R_PPC_PLTREL24      00000000 acl_free + 8000
0000183a 000014fc <unknown: 0xfc>     00000000 .got2 + 800a
0000183e 000014fa <unknown: 0xfa>     00000000 .got2 + 800e
. . .
Relocation section with addend (.rela.text):
r_offset r_info   r_type              st_value st_name + r_addend
. . .
    47: 00000000000007a0   128 FUNC    GLOBAL DEFAULT    2 acl_nfs4_sync_acl_from_mode
    48: 0000000000000458   840 FUNC    GLOBAL DEFAULT    2 acl_nfs4_sync_mode_from_acl
    49: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND groupmember
. . .


But after:

CMD ld -m elf32ppc_fbsd --secure-plt -d -warn-common  -r -d  -o acl_nfs4.kld subr_acl_nfs4.o
CMD ctfmerge -L VERSION -g -o acl_nfs4.kld subr_acl_nfs4.o
CMD :> export_syms
CMD awk -f /usr/src/sys/conf/kmod_syms.awk acl_nfs4.kld  export_syms | xargs -J% objcopy % acl_nfs4.kld

From readelf -a for the acl_nfs4.kld :
(acl_nfs4_sync_mode_from_acl is LOCAL here)

. . .
Relocation section with addend (.rela.text):
r_offset r_info   r_type              st_value st_name + r_addend
. . .
00000076 000004fc <unknown: 0xfc>     00000000 .got2 + 8022
0000007a 000004fa <unknown: 0xfa>     00000000 .got2 + 8026
000001ac 00003012 R_PPC_PLTREL24      00000000 groupmember + 8000
00000234 00002c12 R_PPC_PLTREL24      00000458 acl_nfs4_sync_mode_from_acl + 8000
000002c4 00003212 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
000002f4 00003212 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
0000032c 00003212 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
00000360 00003212 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
0000038c 00003212 R_PPC_PLTREL24      00000000 priv_check_cred + 8000
000007c6 000004fc <unknown: 0xfc>     00000000 .got2 + 800a
000007ca 000004fa <unknown: 0xfa>     00000000 .got2 + 800e
00001026 000004fc <unknown: 0xfc>     00000000 .got2 + 8006
0000102a 000004fa <unknown: 0xfa>     00000000 .got2 + 800a
00001676 000004fc <unknown: 0xfc>     00000000 .got2 + 800a
0000167a 000004fa <unknown: 0xfa>     00000000 .got2 + 800e
00001698 00003c12 R_PPC_PLTREL24      00000000 acl_alloc + 8000
000016a8 00002c12 R_PPC_PLTREL24      00000458 acl_nfs4_sync_mode_from_acl + 8000
00001748 00003912 R_PPC_PLTREL24      00000000 acl_free + 8000
000017e8 00003912 R_PPC_PLTREL24      00000000 acl_free + 8000
0000183a 000004fc <unknown: 0xfc>     00000000 .got2 + 800a
0000183e 000004fa <unknown: 0xfa>     00000000 .got2 + 800e
. . .

Symbol table (.symtab) contains 62 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
. . .
    43: 0000000000000000  1112 FUNC    LOCAL  DEFAULT    1 vaccess_acl_nfs4
    44: 0000000000000458   840 FUNC    LOCAL  DEFAULT    1 acl_nfs4_sync_mode_from_acl
    45: 000000000000181c   248 FUNC    LOCAL  DEFAULT    1 acl_nfs4_check

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)