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July 2010

57 participants
142 discussions

HTX (FPGA) device needs more time for, initialization but HOW?
by Maximilian Thuermer July 2, 2010

July 2, 2010

Hi Knut, this is a problem I ran into multiple times since I've been working with FPGA based HTX boards now and it appears to me there is - as always - no general way to fix that issue. It all depends greatly on the mobo setup. Hard reset isnt always behaving as you would expect. An HT link reinitialization only takes place if either pwrkok goes down (the cold reset case), or ldtstop forces the link into idle state (which most Opterons out there dont seem to support yet). Additionally, almost every mainboard vendor ignores the fact that powerok and reset_n on every HT link is defined as bidirectional. I am working with a Tyan S2912 with fam10 cpus, and its MCP55 seems to control abovementioned signals unidirectionally. If this should be the case with your board, too, there are two possible ways to fix your issue. If you have the southbridge documentation and it truly controls all HT sideband signals, implement your own, real hard reset. Another thing that works on some boards (e.g. on Tyan) is pressing and holding the reset button before pressing the power button and letting it go sometimes afterwards. This holds the southbridge in init state and leaves your card all the time you need to have it program itself. Good luck and best regards, Maximilian Thuermer

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HTX (FPGA) device needs more time for initialization but HOW?
by Knut Kujat July 1, 2010

July 1, 2010

Hi, my version of coreboot (on Supermicro H8QME-2+) is working just fabulous but now I have a little issue. I have a HTX board with a FPGA on it which needs to boot with coreboot on the motherboard. The problem is that it fails to boot most of the time because it doesn't had time to initialize itself properly. I know that because at HT non coherent device initialization it marks bit 1(InitComplete) in the link type register of the device as 0. What I tried to do is to hard_reset() every time it fails but with no luck. I did that because after a power cycle the card seems to have enough time to initialize and the boot process completes successfully. I read in the maillist (http://www.mail-archive.com/coreboot@coreboot.org/msg01089.html) of a similar problem but with no solution published at the end :(. So is there any way how I could delay the whole initialization process to give the card more time? Thanks in advanced, Knut Kujat.

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