[U-Boot] libfdt: make fdt_increase_size() available to everyone

Wolfgang Denk
2010-05-19T22:06:28Z

Dear Kumar Gala,

In message <52E9D06A-E721-4907-9024-11BDC8D006E0@kernel.crashing.org> you wrote:
> So I tried to read this whole thread and got lost in the discussion.
> I'm wondering of something along the following lines would address your
> concerns:

My concerns are simple: if we need to increase the size of the FDT
because we pull in some random amountof data, we should make sure to
have enough room for this, or fail with a clear error message.

And we should not try to use fixed sized buffers, but instead adapt
to the actual amount required by the end user.

Timur assumes that all such code and it's sizess will be known in
advance, and I disagree - other users will have other ideas what they
can do with this, and his assumptions will break.

> #define CONFIG_SYS_FDT_PAD 0x3000

Where exactly is this 0x3000 coming from?

> /* Allow for arch specific config before we boot */
> int __fdt_board_size(void)
> {
> return CONFIG_SYS_FDT_PAD;
> }
> int fdt_board_size(void) __attribute__((weak, alias("__
> fdt_board_size")));
>
>
> int boot_relocate_fdt (struct lmb *lmb, ulong bootmap_base,
> char **of_flat_tree, ulong *of_size)
> {
> ...
>
> if ((fdt_blob + *of_size + fdt_board_size()) >=
> ((char *)CONFIG_SYS_BOOTMAPSZ + bootmap_base))
> relocate = 1;
>
> ...
> }
>
> Than board specific code knows what fix ups might happen and can
> implement dynamic behavior and do something like:

If any board specific code can determine the needed sizes, then how
would such code differ from one board to another?

Why would this in any way be a board specific implementation? This
makes no sense to me. The feature to include some binary data into the
DTB is IMO in no way dependent on or specific to a certain board.

Best regards,

Wolfgang Denk

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