Re: EPIA-M SPD progress [PMX:#]
On Fri, 18 Jul 2003, Dave Ashley wrote: What disadvantages does SPD have other than it is more complex? Wouldn't it let you then be able to correctly use any DDR module you want? some SPD roms have incorrect information. You have to take care with SPD. Overall, SPD is better. However, if you are on a short fuse and need to deliver soon, I would go with probing for now and restrict the type of ram you use. Longer term, we want to do SPD. ron ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
Re: EPIA-M SPD progress [PMX:#]
* ron minnich [EMAIL PROTECTED] [030718 21:12]: On Fri, 18 Jul 2003, Dave Ashley wrote: What disadvantages does SPD have other than it is more complex? Wouldn't it let you then be able to correctly use any DDR module you want? some SPD roms have incorrect information. You have to take care with SPD. Does this happen if you buy cheap ram, or ram of a certain type? How can this kind of problem be avoided? I heard and read this a couple of times now, but (I think) it never happened to me 'til now Stefan -- Architecture Team SuSE Linux AG ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
Re: EPIA-M SPD progress [PMX:#]
On Fri, 18 Jul 2003, Stefan Reinauer wrote: some SPD roms have incorrect information. You have to take care with SPD. Does this happen if you buy cheap ram, or ram of a certain type? You need to find quality vendors and stick with them. Even then, you can get in trouble. How can this kind of problem be avoided? I heard and read this a couple of times now, but (I think) it never happened to me 'til now It can't as long as vendors mix up SEEPROM and DRAM parts incorrectly. ron ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
Re: EPIA-M SPD progress [PMX:#]
src/sdram/smbus_pcibus.inc has some smbus code, I was able to compile it into the epia-m tree and do some test SMBUS_READ_BYTE calls that actually read out values from the ddr eeprom. I had to #if out the section that actually does the dram configuration to get it to compile. I'm in a bad way for experimenting with this, I have to physically remove the BIOS and plug in a new one if something goes bad, and do the reverse to recover. I've fried 2 motherboards with my pliers rubbing out traces under the flashrom socket (good luck fixing that!). If the dram settings are wrong it might make the product flaky. We're trying to field some units for in situ testing real soon, and the system has to be solid. We can probably hardcode the dram configuration for our known good ddr module that we're using mostly. However I'd like the system to function the right way. I'll keep messing with it for now. -Dave some SPD roms have incorrect information. You have to take care with SPD. Overall, SPD is better. However, if you are on a short fuse and need to deliver soon, I would go with probing for now and restrict the type of ram you use. Longer term, we want to do SPD. ron ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
Re: EPIA-M SPD progress [PMX:#] [PMX:#]
On Fri, 18 Jul 2003, Dave Ashley wrote: the BIOS and plug in a new one if something goes bad, and do the reverse to recover. I've fried 2 motherboards with my pliers rubbing out traces under the flashrom socket (good luck fixing that!). you need to go to radioshack and get the flash part extractors. They are perfect for this. Also, failing that, put dental floss under the chip when you install and and then you can lift it out (thanks to Steve James for this one). ron ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
Re: EPIA-M SPD progress [PMX:#]
Stefan Reinauer wrote: * ron minnich [EMAIL PROTECTED] [030718 21:12]: On Fri, 18 Jul 2003, Dave Ashley wrote: What disadvantages does SPD have other than it is more complex? Wouldn't it let you then be able to correctly use any DDR module you want? some SPD roms have incorrect information. You have to take care with SPD. Does this happen if you buy cheap ram, or ram of a certain type? How can this kind of problem be avoided? I heard and read this a couple of times now, but (I think) it never happened to me 'til now SPD only works if the RAM vendor properly programs the serial EEPROM. RAM is a commodity item and vendors churn out millions of modules a year. An assembly line can build thousands of modules per day. If there is a hickup on the procurement side (parts not showing up or late for assembly) an assembler may be forced to use a different part number that is in stock that is still compatible with the module pcb layout but does not have the same timing specs. Other times the SPD info is just programmed wrong and the only QC is based on the end user complaining about a problem. Another way that SPD breaks is by flaky software or SPD bus corruption that writes data to the SPD device on the RAM module. Don't be surprised by how much broken PC hardware gets sent off to market with fixes via BIOS and other still broken means. -Bari ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
Re: EPIA-M SPD progress [PMX:#]
On Fri, 18 Jul 2003 17:07:49 -0500, Bari Ari wrote: Stefan Reinauer wrote: * ron minnich [EMAIL PROTECTED] [030718 21:12]: On Fri, 18 Jul 2003, Dave Ashley wrote: What disadvantages does SPD have other than it is more complex? Wouldn't it let you then be able to correctly use any DDR module you want? some SPD roms have incorrect information. You have to take care with SPD. Does this happen if you buy cheap ram, or ram of a certain type? How can this kind of problem be avoided? I heard and read this a couple of times now, but (I think) it never happened to me 'til now SPD only works if the RAM vendor properly programs the serial EEPROM. RAM is a commodity item and vendors churn out millions of modules a year. An assembly line can build thousands of modules per day. If there is a hickup on the procurement side (parts not showing up or late for assembly) an assembler may be forced to use a different part number that is in stock that is still compatible with the module pcb layout but does not have the same timing specs. Other times the SPD info is just programmed wrong and the only QC is based on the end user complaining about a problem. Another way that SPD breaks is by flaky software or SPD bus corruption that writes data to the SPD device on the RAM module. Don't be surprised by how much broken PC hardware gets sent off to market with fixes via BIOS and other still broken means. -Bari ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios Hi there, I don;t know wether this is of any assistance in your problem, but i recently wrote an application to read and re-program the Serial EEPROMs, used for SPD, to allow a 128Mb part to work in an old 64Mb application. Would this be of any help to anyone? Its a Labview (see www.ni.com) application and the programming was achieved through the PC parallel port. Cheers for now AS -- Alex Scarbro, [EMAIL PROTECTED] on 18/07/2003 ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
Re: EPIA-M SPD progress [PMX:#]
Hi Dave, src/sdram/smbus_pcibus.inc has some smbus code, I was able to compile it into the epia-m tree and do some test SMBUS_READ_BYTE calls that actually read out values from the ddr eeprom. I had to #if out the section that actually does the dram configuration to get it to compile. I'm in a bad way for experimenting with this, I have to physically remove the BIOS and plug in a new one if something goes bad, and do the reverse to recover. I've fried 2 motherboards with my pliers rubbing out traces under the flashrom socket (good luck fixing that!). BIOS Savior will save you. :) -Andrew -- Andrew Ip Email: [EMAIL PROTECTED] Tel:(852) 2542 2046 Fax:(852) 2542 2036 Mobile: (852) 9201 9866 Cwlinux Limited Unit 202B 2/F Lai Cheong Factory Building, 479-479A Castle Peak Road, Lai Chi Kok, Kowloon, Hong Kong. Tel: (852)2542 2046 Fax: (852)2542 2036 For public pgp key, please obtain it from http://www.keyserver.net/en. ___ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
