RE: [Linux-ia64] Re: [PATCH] head.S fix for unusual load addrs

[David Mosberger <davidm@napali.hpl.hp.com>]

Hi Tony,

Great summary!

  Tony> 3) David's suggestion of boot-time relocation.  Probably
  Tony> simplest to implement this in elilo, but if you are really
  Tony> good at PIC asm code it could be done in the kernel startup
  Tony> sequence.

Agreed.  Anyone who's ever debugged the ld.so startup code will agree
that it's much better to do the relocation in elilo.

  Tony>  pros) Just like linking kernel at a new address.  Avoids the
  Tony> __tpa() issue.  Doesn't invalidate any assumptions about how
  Tony> to get from virtual to physical addresses and back again.

  Tony>  cons) Nobody has implemented it.

I think:

	- kernel text addresses vary depending on physical memory conf.

is potentially a bigger issue.  Implementing the relocator in elilo
should be really easy (just take the kernel loader and massage it a
bit).

How many tools are out there that depend on System.map or similar?  I
suppose you could just generate a fresh System.map at boot time (or
have something like /proc/System.map).

	--david