[U-Boot] [PATCH] powerpc/ppc4xx: add ENTRY() to linker script
Add ENTRY() command to the linker script so that entry point is correctly marked in the final ELF file.
Signed-off-by: jozsef imrek mazsi@imrek.org --- arch/powerpc/cpu/ppc4xx/u-boot.lds | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/cpu/ppc4xx/u-boot.lds b/arch/powerpc/cpu/ppc4xx/u-boot.lds index 656f59a..b82e1e8 100644 --- a/arch/powerpc/cpu/ppc4xx/u-boot.lds +++ b/arch/powerpc/cpu/ppc4xx/u-boot.lds @@ -38,6 +38,8 @@ PHDRS bss PT_LOAD; }
+ENTRY(_start) + SECTIONS { /* Read-only sections, merged into text segment: */
Dear jozsef imrek,
In message 1301002747-8943-1-git-send-email-mazsi@imrek.org you wrote:
Add ENTRY() command to the linker script so that entry point is correctly marked in the final ELF file.
Which exact problem are you trying to fix?
Best regards,
Wolfgang Denk
dear wolfgang,
On Fri, 25 Mar 2011, Wolfgang Denk wrote:
Add ENTRY() command to the linker script so that entry point is correctly marked in the final ELF file.
Which exact problem are you trying to fix?
i'm sorry, i probably should have been more verbose in the changelog.
when cross-compiling u-boot for the avnet virtex-4 minimodule (make fx12mm_config; make, with SYS_TEXT_BASE=0x02000000) i end up with a u-boot.lds linker script that has no ENTRY() command.
this will result in an incorrect ELF file: the entry point in the ELF header points to the first byte of the first loadable segment (which is ~the version string at 0x02000004: "U-Boot 2011..") instead of the first instruction to be executed at _start (at 0x02002100 in this case).
powerpc-405-linux-gnu-readelf -e u-boot:
ELF Header: Magic: 7f 45 4c 46 01 02 01 00 00 00 00 00 00 00 00 00 Class: ELF32 Data: 2's complement, big endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: EXEC (Executable file) Machine: PowerPC Version: 0x1 Entry point address: 0x2000000 ..
powerpc-405-linux-gnu-objdump -d u-boot:
Disassembly of section .text:
02000000 <version_string-0x4>: 2000000: 27 05 19 56 dozi r24,r5,6486
02000004 <version_string>: 2000004: 55 2d 42 6f rlwinm. r13,r9,8,9,23 2000008: 6f 74 20 32 xoris r20,r27,8242 200000c: 30 31 31 2e addic r1,r17,12590 2000010: 30 33 2d 72 addic r1,r19,11634 ...
02002100 <_start>: 2002100: 38 80 00 00 li r4,0 2002104: 7c 99 eb a6 mtpmc1 r4 2002108: 7c 9a eb a6 mtdcwr r4 200210c: 7c 94 f3 a6 mtesr r4 2002110: 7c 9a f3 a6 mttcr r4 ...
anything trying to load and run this ELF file (eg xilinx's XMD debugger, or a bootloader stored in the FPGA fabric) will fail to do so because the processor will jump to 0x02000000 and try to execute the version string.
best regards,
Hi Jozsef,
On Friday 25 March 2011 00:54:18 jozsef imrek wrote:
Add ENTRY() command to the linker script so that entry point is correctly marked in the final ELF file.
Which exact problem are you trying to fix?
i'm sorry, i probably should have been more verbose in the changelog.
Yes. Please resend this patch as v2, with the extended commit text so that I may apply it in this merge window.
Thanks.
Cheers, Stefan
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participants (3)
-
jozsef imrek -
Stefan Roese -
Wolfgang Denk