[U-Boot-Users] Difficulty with symbol maps.

Mark Doherty mdoherty at arca-technologies.com
Fri Aug 1 15:38:06 CEST 2003


I am experiencing some difficulty loading my symbol table into gdb, I'm not 
sure whether it is a common fault with gdb or perhaps finger trouble on my 

I have built u-boot for an ep8260 & my custom target such that the code
in flash memory at 0xFF000000. However the reset configuration word is 
programmed to initialise flash at address 0x00000000. This appears to work
as the board does indeed boot correctly. However I would like to be able to 
step through the code using a BDI2000. 

When I attempt to load the symbol file into gdb at address 0x00000000, the 
symbol _start which I expected to reside at 0x100 actually resides at
0xFE000100 as illustrated in the following trace.

$ ppc-linux-gdb
GNU gdb 5.1.1
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "--host=i386-redhat-linux --target=ppc-linux".
(gdb) bdi
0x00000100 in ?? ()
(gdb) add-symbol-file u
u-boot       u-boot.bin   u-boot.map   u-boot.srec
(gdb) add-symbol-file u-boot 0x00000000
add symbol table from file "u-boot" at
        .text_addr = 0x0
(y or n) y
Reading symbols from u-boot...done.
(gdb) info address _start
Symbol "_start" is at 0xfe000100 in a file compiled without debugging.

Interestingly, when I attempt to load the symbol map at any other address 
than zero the symbols appear fine. 

Any ideas or thoughts would be appreciated.

Many thanks

Mark Doherty.

More information about the U-Boot mailing list