On 06.02.2012 22:17, Albert ARIBAUD wrote:
Le 06/02/2012 20:27, Mike Frysinger a écrit :
On Monday 06 February 2012 09:49:27 Tom Rini wrote:
On Mon, Feb 6, 2012 at 1:43 AM, Graeme Russ wrote:
On 02/06/2012 06:51 PM, Wolfgang Denk wrote:
Graeme Russ wrote:
I think the immediate focus should be on centralising the init sequence processing into /common/init.c and then bringing the new'initcall' architecture online
Agreed.
Once these have been done, any board can just specific:
SKIP_INIT(RELOC)
I will probably object to his, too - for the same reasons.
Considering this is a 'free' artefact of how the init sequence functions, and that it is board specific and totally non-invasive for anyone else (i.e. no ugly ifdef's anywhere else in the code) I'm surprised you would object...
To pick up Wolfgang's argument, but why do we want to skip relocation? You can debug through it, it's documented (official wiki has GDB, over in TI-land, the wiki page for CCS has the bits for doing it in that Eclipse-based env, other debuggers I'm sure have a similar "now add symbols at this offset from link" option) and the end result makes it very easy for end-users to break their world (default kernel load addrs being where U-Boot would be).
if you have a static platform which never changes, isn't the relocation a waste of time ? i can understand wanting relocation by default for platforms where memory sizes are unknown, but it's not uncommon for people to have fixed hardware when they deploy.
Relocation may not be a waste of time if the static platform boots U-Boot from NOR, as relocation will be needed to move U-Boot to RAM in working order.
Now if the platform is static and has a preloader of sorts, then one can predict (or just observe) where U-Boot would want to relocate, and set the preloader once and for all (for a given release of U-Boot, that is) to load U-Boot directly at that address. U-Boot will skip copy and relocation if it already resides at the right address.
For the i.MX6 preloader, i.e. the i.MX6 boot ROM, the issue I observed is that the copy *and* relocation will be skipped [1]. The skipped copy is fine, skipping the relocation breaks things, though:
Getting the address where U-Boot will relocate to, and setting this as CONFIG_SYS_TEXT_BASE will result in skipping the copy. Fine. But the whole 'fix .rel.dyn relocations' in e.g. arch/arm/cpu/armv7/start.S is skipped, too. And this breaks things.
Best regards
Dirk
[1] http://lists.denx.de/pipermail/u-boot/2012-February/117134.html