xscale documentation: vector table handling

xscale documentation: vector table handling

Hi everyone.  I noticed some incorrect information in the user manual
regarding how the vector table is handled on the xscale, so for your
consideration, here's a short patch that corrects it, and adds a
little more detail I thought might be helpful.

The documentation states that OpenOCD does not attempt to synchronize
the vector tables in memory with those stored in the "mini instruction
cache".  In fact, on each resume it does copy from memory to the cache
all entries in the high and low tables that were not previously
defined using the 'xscale vector_table' command. (In
src/target/xscale.c, see xscale_update_vectors(), which is invoked by
xscale_resume().)  I take advantage of this during Linux boot-up.  The
extra detail describes in general terms how I do this.

Corrections, comments are of course gratefully received.

Thanks,
Mike

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>