Date: Wed, 21 Feb 2007 00:43:14 +0100 From: Bernd Walter <ticso@cicely12.cicely.de> To: "M. Warner Losh" <imp@bsdimp.com> Cc: freebsd-arm@freebsd.org Subject: Re: What goes wrong? Message-ID: <20070220234313.GD24769@cicely12.cicely.de> In-Reply-To: <20070220.122351.-432837306.imp@bsdimp.com> References: <20070220075204.GI66059@x12.dk> <45DADFCD.7000209@bulinfo.net> <20070220.122351.-432837306.imp@bsdimp.com>
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On Tue, Feb 20, 2007 at 12:23:51PM -0700, M. Warner Losh wrote: > In message: <45DADFCD.7000209@bulinfo.net> > Krassimir Slavchev <krassi@bulinfo.net> writes: > : Try to change the BOOT_FLAVOR in the /usr/src/sys/boot/arm/at91/Makefile > : > : Soeren Straarup wrote: > : > Hi > : > > : > What goes wrong when i send via serial xmodem the bootspi to the arm board > : > and all i get back is some unreadable chars? > : > I'm doing this from windows via teraterm at 115200 > > The root cause of 'unreadable' characters usually is that your board > uses a different base oscillator than the board you've compiled the > defaults for. The second cause can be bad memory parameters, but > that's less common (it usually manifests itself in the kernel failing > to print the right amount of memory). Since the PLLs that run the > serial port are derived from the base christal frequency, bad things > happen downstream. > > We should likely document these failings and how to work around them. > Better yet would be to 'bloat' the boot loader a little and have it > use the atmel facilities for discovering the base frequency. Bloating > it to cope with different SDRAM would be a much harder task... You have to do the PLL calculation as well - asuming you want the typical 180MHz, but there are good reasons one don't want too. Bloating the loader in special cases e.g. boards which may be populated with just two differend kind of SDRAM configuration, should be Ok. Board specific needs vary too much to get a sensible autoprobing for everything required, e.g. noone knows the required GPIO setup. If bloating the loader, I'd prefer diagnostic and informative output, such as printing the base frequency, the SDRAM, e.g. I already localy put a small (no perfect) SDRAM test in boot0spi to enshure basic functionality befor starting. Since I have an IIC header, I already plan to switch from boot0spi/ boot2 xmodem chain to plug an iic-rom, which tests hardware and loads boot2 via TFTP. I personally hope that mr@ can help us getting a complete ficl loader up one day. -- B.Walter http://www.bwct.de http://www.fizon.de bernd@bwct.de info@bwct.de support@fizon.de
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