From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert ARIBAUD Date: Wed, 11 Jun 2014 09:14:49 +0200 Subject: [U-Boot] enbw_cmc, da850evm_direct_nor, and calimain vectors table misaligned (was: [PATCH] arm: fix a build error with CONFIG_USE_IRQ) In-Reply-To: <20140609182926.95C2.AA925319@jp.panasonic.com> References: <20140609163656.95BE.AA925319@jp.panasonic.com> <20140609182926.95C2.AA925319@jp.panasonic.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Masahiro, (to: the board maintainers for enbw_cmc, da850evm_direct_nor, and calimain) On Mon, 09 Jun 2014 18:29:26 +0900, Masahiro Yamada wrote: > Hi Albert, > You changed the behaviour of three boards, > "enbw_cmc", "da850evm_direct_nor", "calimain"! > Probably they are broken. > > These boards expects "0x00000011" (=CONFIG_SYS_DV_NOR_BOOT_CFG) > at the beginning of the image. > But since commit 41623c91, that is missing. > > If you still don't understand, you should checkout 41623c91^ and > 41623c91 and compare u-boot.dis. Your description of the effects of my change is correct. However, this raises another question which I would like to see discussed before doing anything about these boards. Taking the last commit where the prefix word was actually emitted (that is, 41623c91^, which is actually 60a4f39f, "arm: remove unused _end_vect and _vectors_end symbols"), and reading arch/arm/cpu/arm926ejs/start.S, I see that the start of the image looks like this: offset Content +0x0000 prefix word CONFIG_SYS_DV_NOR_BOOT_CFG +0x0004 reset vector +0x0008 undefined instruction vector +0x000c software interrupt vector +0x0010 prefetch abort vector +0x0014 data abort vector +0x0018 unused +0x001c irq vector +0x0020 fiq vector +0x0024 (end of vectors table) And that is /wrong/: the vectors table is misaligned by 4 bytes. Obviously, the boards have been working fine for a long time, because no exception vector was used apparently (or because when exceptions did happen, the error was debugged without the need to analyze the exception). I suspect we could just remove the '.word CONFIG_SYS_DV_NOR_BOOT_CFG' line from the vectors.S file and prepend the word to the image /after/ linking. This, of course, requires confirmation from maintainers. Manfred, Christian, Sudhakar, Heiko: can any one of you let us know the reason for this signature word exactly, and how exactly it is used by the board? Ideally, can you also: - test a current build (which does not have the signature word) and confirm it fails to load); - test the same build with the 4-byte signature manually prepended (this may possibly require padding the image); > Best Regards > Masahiro Yamada Amicalement, -- Albert.