From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert ARIBAUD Date: Sun, 30 Jan 2011 10:36:17 +0100 Subject: [U-Boot] SPI flash protection In-Reply-To: <20110129170048.GE20942@kw.sim.vm.gnt> References: <20110129170048.GE20942@kw.sim.vm.gnt> Message-ID: <4D453111.50107@free.fr> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Simon :) Le 29/01/2011 18:00, Simon Guinot a ?crit : > Hi, > > I am looking to add U-Boot support for the LaCie Network Space v2 board. > > The SoC is a Kirkwood 88F6281_A0 and the boot device is a Macronix SPI > flash (MX25L4005A). My problem is that the embedded stock U-Boot (1.1.4 > version patched by Marvell and LaCie) enable write protection for the > SPI flash. Then, after an U-Boot update, turn off this protection is > needed to allow saving U-Boot environment. > > It is not clear for me how to proceed. Disable the write protection from > the board setup code could be an idea but a problem is that the SPI flash > API don't export any helpful method... > Maybe I should add one ? > > An another idea is disabling the write protection anyway while > initializing the flash (from the low level macronix driver). It is quite > straightforward but I don't know if a flash driver is allowed to do > that. After all, a flash could be protected for some good reasons. > > My last idea is doing nothing and let an another piece of software > handle the problem... > > Thanks in advance for advices. My personal take: let users of the board do their own mistakes and thus, do not protect the Flash, *except* for U-Boot itself. So, if SPI Flash protection is possible on block or sector levels, protect the blocks/sectors where U-Boot is located, including the environment. Saveenv should unprotect and re-protect the environment sector/block. As for the kernel and rootfs... You can either leave them unprotected or protected. > Simon > > PS: some pointers about this project: > > git : http://git.lacie-nas.org/u-boot-lacie.git (branch netspace_v2) You should keep this branch based on u-boot/master generally, and on u-boot-arm/master right now because it has the most recent ARM commits. Amicalement, -- Albert.