From mboxrd@z Thu Jan 1 00:00:00 1970 From: Angelos Manousarides Date: Wed, 21 Jun 2006 13:48:21 +0300 Subject: [U-Boot-Users] Dynamic location of the environment sector In-Reply-To: <20060614143104.145D9353C1B@atlas.denx.de> References: <448FF915.5060306@inaccessnetworks.com> <20060614143104.145D9353C1B@atlas.denx.de> Message-ID: <20060621104820.GA23461@inaccessnetworks.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed, Jun 14, 2006 at 04:31:04PM +0200, Wolfgang Denk wrote: > > Currently the defines for the environment expect raw numerical values. > > What makes you think so? > > I didn't try it, but I see no reason why something like > > #define CFG_ENV_ADDR my_env_params(1) > #define CFG_ENV_SIZE my_env_params(2) > #define CFG_ENV_SECT_SIZE my_env_params(3) > > would be impossible. But this probably does not solve your problem - > see below. Indeed it does not. The problem however, just for the record is code like the following segment: # if (CFG_ENV_ADDR >= CFG_MONITOR_BASE) && \ (CFG_ENV_ADDR+CFG_ENV_SIZE) <= (CFG_MONITOR_BASE + CFG_MONITOR_LEN) # define ENV_IS_EMBEDDED 1 # endif The preprocessor cannot obviously perform checks and do arithmetic with C variables and constructs: include/environment.h:64:20: token "[" is not validin preprocessor expressions > > And all sizes are detected correctly. I want to use these values to > > calculate the location of the environment dynamically at runtime. This > > way I can have a single u-boot image for all flash configurations! > > There is one problem which you probably did not realize yet: U-Boot > will access the environment (for example, to read the console > baudrate) *long* before the flash detection code is running (which > actually happens very late in the init sequence, after relocation to > RAM). So you cannot rely on values filled in the flash_info[] array, > as such data does not exist yet when you need it. You will need some > other way (like configuration registers of jumpers on the board) to > figure out which configuration to use. > > Or you simply chose a definition that works on all boards, even if > this means that you will waste some flashmemory on 2 of the board > configurations. This is the solution I will follow, although I was trying to avoid it. The second block, right after the u-boot will hold the environment. I have an issue though with the environment sector size. I have three configurations, two of which have a sector size 0x40000 and one has 0x20000. The problem I mentioned above with the static declarations appears here. If I declare the env size to be the smaller sector, An error occurs during the environment saving : "flash sector size is not equal to the environment size" or something like that. Another note not related to the ones above. A couple of days ago I sent some patches for the arm architecture, but I did not received any replies. Have you seen them (it was on the 6th of June)? Regards, Angelos Manousaridis