[RTEMS Project] #4266: motorola_powerpc bootloader images not linking correctly

[RTEMS trac]

#4266: motorola_powerpc bootloader images not linking correctly
-------------------------+--------------------------
 Reporter:  Chris Johns  |       Owner:  Chris Johns
     Type:  defect       |      Status:  reopened
 Priority:  normal       |   Milestone:  5.2
Component:  bsps         |     Version:  5
 Severity:  normal       |  Resolution:
 Keywords:               |  Blocked By:
 Blocking:               |
-------------------------+--------------------------
Changes (by Chris Johns):

 * status:  closed => reopened
 * resolution:  fixed =>


Comment:

 The change does not resolve the issue. I am not sure what happened in my
 testing.

 The bootloader linked executable has the `.text.*` sections present. I am
 wondering if the Motorola debug monitor is not capable of loaded this type
 of ELF file. As a result the card information is not found and boot
 process fails. You can observe this by running `readelf -a` on the
 `rtems.img.elf` file created when making the image file. This is the RTEMS
 5 executable linked with the RTEMS 6 bootloader:
 {{{
 Section Headers:
   [Nr] Name              Type            Addr     Off    Size   ES Flg Lk
 Inf Al
   [ 0]                   NULL            00000000 000000 000000 00      0
 0  0
   [ 1] .text             PROGBITS        00000000 010000 00f145 00  AX  0
 0 32
   [ 2] .eh_frame         PROGBITS        0000f148 01f148 0017e0 00   A  0
 0  4
   [ 3] .image            PROGBITS        00010928 020928 017778 00  WA  0
 0  1
   [ 4] .reloc            PROGBITS        000280a0 0380a0 0002bc 00  WA  0
 0  4
   [ 5] .handlers         PROGBITS        0002835c 03835c 0003ac 00  WA  0
 0  1
   [ 6] .data             PROGBITS        00028720 038720 003c80 00  WA  0
 0 32
   [ 7] .bss              NOBITS          0002c3a0 03c3a0 001158 00  WA  0
 0 32
   [ 8] .gnu.attributes   GNU_ATTRIBUTES  00000000 03c3a0 000010 00      0
 0  1
   [ 9] .symtab           SYMTAB          00000000 03c3b0 0066c0 10     10
 698  4
   [10] .strtab           STRTAB          00000000 042a70 00616c 00      0
 0  1
   [11] .shstrtab         STRTAB          00000000 048bdc 00005e 00      0
 0  1
 }}}
 The RTEMS 6 executable has more code than the RTEMS 5. I tried a number of
 combinations in the linker command script but could not find a suitable
 result.

 I have now looked into fixing the building of the bootloader in the RTEMS
 5 `automake` build system and there are some fundamental issues present
 and I am yet to decide how this is to be resolved.

 The bootloader `Makefile` has a variable `BOOTLOADER_CPU_FLAGS`:
 https://git.rtems.org/rtems/tree/c/src/lib/libbsp/powerpc/motorola_powerpc/bootloader/Makefile.am?h=5#n22
 This is empty because `CPU_FLAGS` is not exported into this file:
 {{{
 $ grep CPU_FLAGS powerpc-
 rtems5/c/mvme2307/lib/libbsp/powerpc/motorola_powerpc/bootloader/Makefile
 $
 }}}
 The CPU flags are being provided the globally set `CFLAGS` and this
 includes the text and data segment flags which is causing the problem.
 Adding:
 {{{
 CFLAGS =
 CPPFLAGS =
 CCASFLAGS =
 }}}
 Results in no valid CPU flags being set.

 I am reluctant to add exporting the CPU flags to a high level in the build
 process because it will be seen by all BSPs and it is very difficult to
 know if there are possible side effects in another BSP.

 I cannot only see a couple of solutions:

 1. Remove the problem flags from the build

 2. Find a way to include the config with the flags

--
Ticket URL: <http://devel.rtems.org/ticket/4266#comment:2>
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