From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Samuelsson Date: Wed, 30 May 2007 20:11:50 +0200 Subject: [U-Boot-Users] Question about CFG_ENV_ADDR during RAMBOOT References: <20070530134348.B78E3353AF8@atlas.denx.de> Message-ID: <019101c7a2ef$47bcfdc0$0302a8c0@atmel.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de ----- Original Message ----- From: "Wolfgang Denk" To: "Ladislav Michl" Cc: "Ulf Samuelsson" ; "uboot" Sent: Wednesday, May 30, 2007 3:43 PM Subject: Re: [U-Boot-Users] Question about CFG_ENV_ADDR during RAMBOOT > In message <20070530105256.GA7649@michl.2n.cz> you wrote: >> >> > If you fix anything, then please by making it compatible with the >> > poublic U-Boot source tree,i. e. by using the mtdparts command for >> > this purpose. >> >> Here it might be usefull to avoid modifications of certain partition >> sizes. For example partition containing environment shouldn't be >> modified, because code which read it from U-Boot has size and offset >> hardcoded, therefore modifying it will result to bad surprise... > > The user might prepare for the installation of a new version of > U-Boot where the environment is in new sectors (for example, because > U-Boot has grown after adding new features - been there before), or > for switching from single to redundant environment, or ... > > So actually the user might want to do some clever thing. Please don;t > prevent him from doing that. > Since everything I work on is dataflash based, U-Boot executes from SDRAM. While certain partitions are write protected, you an easily unprotect any or all of the dataflash pages. >From U-Boot you then can download the new U-Boot image to SDRAM using tftp and then cp.b (at least for now :-) to dataflash and then reboot. The new image has defined it own partitions, and the environment area (defined by the new image) is initialized according to compile time values of the new image While the named partitions will initialize some environment variables, there is nothing that forces the user to actually use these in the bootargs or anywhere else. I want the novice user to have a straightforward path to boot Linux without hassle. This does not block anyone else from shooting themselves in the foot. > Best regards, > > Wolfgang Denk > > -- Best Regards Ulf Samuelsson ulf at atmel.com Atmel Nordic AB Mail: Box 2033, 174 02 Sundbyberg, Sweden Visit: Kavalleriv?gen 24, 174 58 Sundbyberg, Sweden Phone +46 (8) 441 54 22 Fax +46 (8) 441 54 29 GSM +46 (706) 22 44 57 Technical support when I am not available: AT90 AVR Applications Group: mailto:avr at atmel.com AT91 ARM Applications Group: mailto:at91support at atmel.com AVR32 Applications Group mailto:avr32 at atmel.com http://www.avrfreaks.net/; http://avr32linux.org/ http://www.at91.com/ ; ftp://at91dist:distrib at 81.80.104.162/