From mboxrd@z Thu Jan 1 00:00:00 1970 From: swarren@wwwdotorg.org (Stephen Warren) Date: Wed, 31 Jul 2013 10:57:36 -0600 Subject: [PATCH] ARM: allow DEBUG_UNCOMPRESS for omap2plus In-Reply-To: <20130731064634.GR7656@atomide.com> References: <1375224558-8170-1-git-send-email-swarren@wwwdotorg.org> <20130730225233.GF21614@n2100.arm.linux.org.uk> <51F845C7.8020106@wwwdotorg.org> <20130731064634.GR7656@atomide.com> Message-ID: <51F94200.2060202@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/31/2013 12:46 AM, Tony Lindgren wrote: > * Stephen Warren [130730 16:08]: >> 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 >>>> >>>> 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)? > > I think we're best off removing the remaining uncompress code > configured port detection features as the port properties are now > defined in kconfig anyways. That simplifies the code quite a bit. If you want to do that with OMAP, I'm happy to drop this patch. For Tegra, automatic determination of the DEBUG_LL UART is rather useful, so I'm not going to give that up:-)