[PATCH] ARM: allow DEBUG_UNCOMPRESS for omap2plus

[Stephen Warren]

On 07/30/2013 04:52 PM, Russell King - ARM Linux wrote:
> On Tue, Jul 30, 2013 at 04:49:18PM -0600, Stephen Warren wrote:
>> From: Stephen Warren <swarren at nvidia.com>
>>
>> DEBUG_UNCOMPRESS was previously disallowed for omap2plus due to
>> omap2plus.S's use of .data, which is not allowed in the decompressor.
>> Solve this by placing that data into .text when building the file into
>> the decompressor. This relies on .text actually being writable in the
>> decompressor, which it is in practice.
> 
> Unless you decide to use ZBOOT and flash the zImage.

I knew there had to be a catch:-)

I have no idea if ZBOOT is a use-case that's relevant to OMAP?

On Tegra at least (the same issue applies to the other patch I just
sent), that use-case is almost impossible; even if the boot ROM directly
booted a kernel, the boot ROM is hard-coded to copy whatever it's
booting to SDRAM first, although I suppose if that was a boot-loader it
could just jump back to a ROM location. That said, NOR flash is
extremely rare on Tegra. So, I don't know if we care about this issue.

Is it reasonable to just say "If you use ZBOOT, don't enable
DEBUG_UNCOMPRESS"? Perhaps these patches should not completely remove
the !DEBUG_TEGRA_UART from config DEBUG_UNCOMPRESS, but instead say:

default y if DEBUG_LL && (!DEBUG_TEGRA_UART || !ZBOOT)?