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Where are the samples for these? I want to test this out for pc386. Does
it support pc386 yet?<br>
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Eugeny S. Mints wrote:<br>
<blockquote type="cite" cite="mid:Pine.LNX.4.33.0303031115001.17406-100000@mail.oktet.ru">
<pre wrap="">On Mon, 3 Mar 2003, Thomas Doerfler wrote:<br><br></pre>
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<pre wrap="">------- Forwarded message follows -------<br>From: "Thomas Doerfler" <a class="moz-txt-link-rfc2396E" href="mailto:Thomas.Doerfler@imd-systems.de"><Thomas.Doerfler@imd-systems.de></a><br>Organization: IMD<br>To: Chris Caudle <a class="moz-txt-link-rfc2396E" href="mailto:chris@chriscaudle.org"><chris@chriscaudle.org></a><br>Date sent: Mon, 03 Mar 2003 09:01:38 +0100<br>Subject: Re: DOSFS bug fixes, IDE drivers and sample released<br>Copies to: Thomas Doerfler <a class="moz-txt-link-rfc2396E" href="mailto:Thomas.Doerfler@imd-systems.de"><Thomas.Doerfler@imd-systems.de></a><br>Priority: normal<br><br><br><br></pre>
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<pre wrap="">On Sunday 02 March 2003 9:48 am, Joel Sherrill wrote:<br></pre>
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<pre wrap="">filed as PR 367/368/369 in the GNATS system, see:<br></pre>
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<pre wrap="">Does the driver filed in PR 368 support DMA transfer yet, or programmed I/O<br>only?<br><br></pre>
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<pre wrap="">It is really a minimal implementation, supporting PIO mode.<br>Actually I am not so aware about various IDE transfer modes,<br>the integration of DMA into the PC architecture an so on, my<br>goal was to implement at least basic harddisc support.<br></pre>
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<pre wrap=""><!----><br>Actually the answer is the following: DMA and POI modes are<br>entities which belong to generic high level ATA driver<br>implemented in ata.c file. In other words wether the data<br>will be transferred in PIO or DMA mode depends on ATA<br>commands issued. In general, low level IDE drivers (as<br>Thomas drivers written for i386 and mbx8xx) just "pass" ATA commands to an<br>IDE chip just by providing ability for writing any data to a<br>chip registers. In addition to the basic<br>functionality described above, current IDE drivers have<br>several routines for optimization of data read/write in PIO<br>mode (*_ide_read_block/*pc386_ide_write_block).<br><br>So, any low level IDE driver has ability to support PIO and<br>DMA modes by definition (but of course current low IDE<br>drivers may need some update for DMA support) and the issue<br>depends on generic ATA driver implementaion. Unfortunately, current ATA<br>driver implementation supports only
PIO mode, but from the<br>beggining was designed to allow easy extension (I<br>mean addition of new ATA commands). So, generic ATA driver<br>should be modified for DMA mode support.<br><br></pre>
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<pre wrap="">So here is a lot of space to improve things :-)<br></pre>
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<pre wrap=""><!----><br>Agree:)))<br><br>Hope, this helps,<br> Eugeny<br><br><br></pre>
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