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Hi,<br><br>I was looking at Intel ICH SPI specs, and saw that there are a few registers on hardware sequencing. I was hence thinking on the feasibility of hardware sequencing. <br><br>But then I saw that for hardware sequencing, I cannot find any registers where I can input opcodes like reading/writing to status registers. This is unlike software sequencing, where there is actually pre-op (06h) and other opcodes like 01h (writing status register) and 05h (reading status register).<br><br>So I was thinking if the host CPU/Bios Master can actually still do flashing of the Bios itself using hardware sequencing, without the need of pre-op such as 06h?<br><br>Thanks!<br><br><br><br>> Date: Tue, 30 Mar 2010 03:19:00 +0200<br>> From: c-d.hailfinger.devel.2006@gmx.net<br>> To: btwvolcano@live.com<br>> CC: flashrom@flashrom.org<br>> Subject: Re: [flashrom] Hardware Sequencing vs Software Sequencing<br>> <br>> Hi John,<br>> <br>> On 30.03.2010 02:47, john warwick wrote:<br>> > I was looking through the code, and see that flashrom is using software sequencing. Is there any reason for software sequencing to be chosen instead of hardware sequencing?<br>> > <br>> <br>> Assuming that you're talking about the Intel ICH SPI code, here's the<br>> info I have:<br>> Yes, there are multiple reasons why hardware sequencing is not supported:<br>> - You can't reflash the complete chip, just the region for the current<br>> (BIOS) descriptor.<br>> - You're unable to read the whole chip.<br>> - If you exchange the flash chip, write/erase may fail in random ways.<br>> - Crossflashing/hotflashing is pretty much impossible.<br>> - Nobody implemented it.<br>> <br>> <br>> > Are there any restrictions imposed for hardware sequencing?<br>> > <br>> <br>> Please see above.<br>> <br>> Of course, if you're willing to contribute code for ICH SPI hardware<br>> sequencing, we'll be glad to review and merge it. Please be warned that<br>> this is a rather difficult task, especially because flashrom assumes<br>> that a flash chip can be accessed in full and you'll either have to<br>> emulate this or change flashrom safety checks and code flow in a few<br>> strategic places.<br>> <br>> Regards,<br>> Carl-Daniel<br>> <br>> -- <br>> http://www.hailfinger.org/<br>> <br> <br /><hr />Hotmail: Trusted email with Microsoft’s powerful SPAM protection. <a href='http://clk.atdmt.com/GBL/go/210850552/direct/01/' target='_new'>Sign up now.</a></body>
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