[U-Boot-Users] Jump vector table after relocation

Umar Qureshey umarq at quartics.com
Thu Jan 5 00:33:22 CET 2006


I am studying the startup code in cpu/arm926ejs/start.S.  I have a 
question regarding relocation.  I understand how and under what 
conditions the code is relocating.  But it seems to me that during 
relocation, u-boot copies verything including the jump vector table to 
the RAM.  However, the CPU is only aware of a fixed address for the 
vector jump table i.e. 0x00000000.  So my question is, is this copying 
redundant?  Or does the CPU somehow use the newly copied table residing 
in RAM, rather than the original flash one?  On the ARM Integrator/CP 
board I am using, external switches do allow RAM to be located at 
0x00000000 instead of flash but I don't think this switch can be done at 
run time. 



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