[U-Boot-Users] bd_info vs. global_data
Wolfgang Denk
wd at denx.de
Sat Nov 11 00:03:54 CET 2006
In message <4554AB0E.7000805 at freescale.com> you wrote:
>
> So gd initially lives in cache? I don't see in the README where it says where
> gd_t is initially allocated, but I do see this in the code:
This depends on the architecture. It may be cache, or some on-chip
memory, or some SRAM, or whatever is available on a board that works
as RAM without specific initialization.
> However, it looks like there's some redundancy in this. Couldn't the variable
> disable_of perform the same function? Or even better, couldn't we just check
No, it cannot. Because the change was done a long time ago in the 2.4
kernel tree, somewhere around 2.4.5-pre5. Using a 2.4.4 kernel or a
2.4.5 kernel require different clock encoding (one in MHz, the other
in Hz). This does not depend on any OF stuff at all.
> whether a pointer to an OF tree is passed to the bootm parameter? If the user
> includes an OF tree on the bootm command line, then boot an OF kernel.
> Otherwise, convert the frequency values to MHZ and boot a traditional kernel.
It seems you did not read much of the documentation.
> Speaking of do_bootm_linux(), why is the PPC version of this function in
> cmd_bootm.c instead of lib_ppc/ppc_linux.c?
For historical reasons. We started with PPC only, so it was natural
to have this in cmd_bootm.c. Other architectures placed theit code
somewhere else, but nobody changed the PPC code.
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
GUIs are virtually useless. Learn tools. They're configurable,
scriptable, automatable, cron-able, interoperable, etc. We don't need
no brain-dead winslurping monolithic claptrap.
-- Tom Christiansen in 371140df at csnews
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