Date: Thu, 20 Apr 2017 04:06:34 +0000 (UTC) From: Benjamin Kaduk <bjk@FreeBSD.org> To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r50185 - head/en_US.ISO8859-1/htdocs/news/status Message-ID: <201704200406.v3K46Ywf075841@repo.freebsd.org>
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Author: bjk Date: Thu Apr 20 04:06:34 2017 New Revision: 50185 URL: https://svnweb.freebsd.org/changeset/doc/50185 Log: Add 2017Q1 entry on eMMC and SD card improvements from marius Modified: head/en_US.ISO8859-1/htdocs/news/status/report-2017-01-2017-03.xml Modified: head/en_US.ISO8859-1/htdocs/news/status/report-2017-01-2017-03.xml ============================================================================== --- head/en_US.ISO8859-1/htdocs/news/status/report-2017-01-2017-03.xml Thu Apr 20 03:40:07 2017 (r50184) +++ head/en_US.ISO8859-1/htdocs/news/status/report-2017-01-2017-03.xml Thu Apr 20 04:06:34 2017 (r50185) @@ -954,4 +954,95 @@ <task>Submit the remaining fixes and drivers.</task> </help> </project> + + <project cat='proj'> + <title>Support for eMMC flash and Faster SD Card Modes</title> + + <contact> + <person> + <name> + <given>Marius</given> + <common>Strobl</common> + </name> + <email>marius@FreeBSD.org</email> + </person> + </contact> + + <body> + <p>In r315430, support for eMMC partitions has been added to + <tt>mmc(4)</tt> and <tt>mmcsd(4)</tt> in &os; 12. Besides the + user data area, i.e., the default partition, eMMC v4.41 and + later devices can additionally provide up to:</p> + + <ul> + <li>1 enhanced user data area partition</li> + + <li>2 boot partitions</li> + + <li>1 RPMB (Replay Protected Memory Block) partition</li> + + <li>4 general purpose partitions (optionally with a enhanced + or extended attribute)</li> + </ul> + + <p>Apart from simply subdividing eMMC flash devices or having + UEFI code in the boot partition, as is done on some Intel NUCs, + another use case for partition support is the activation of + pseudo-SLC mode, which manufacturers of eMMC chips typically + associate with the enhanced user data area and/or the enhanced + attribute of general purpose partitions.</p> + + <p>In order to be able to partition eMMC devices, r315430 also + added a Linux-compatible IOCTL interface to <tt>mmcsd(4)</tt>. + This allows for using the GNU <tt>mmc-utils</tt> (found in ports + as <tt>sysutils/mmc-utils</tt>) on &os;. Besides partitioning + eMMC devices, the <tt>mmc</tt> tool can also be used to query + for life time estimate and pre-EOL information of eMMC flash, as + well as to query some basic information from SD cards.</p> + + <p>CAVEAT EMPTOR: Partitioning eMMC devices is a one-time + operation.</p> + + <p>Additionally, in order to make eMMC flash devices more + usable, support for DDR (Dual Data Rate) bus speed mode at a + maximum of 52 MHz (DDR52) has been added to <tt>mmc(4)</tt> + and <tt>sdhci(4)</tt> in r315598, i.e., in &os; 12. Compared + to high speed mode (the previous maximum) at 52 MHz, DDR52 + mode increases the performance of the tested eMMC chips from + ~45 MB/s to ~80 MB/s.</p> + + <p>So far, support for DDR52 mode has been enabled for the eMMC + controllers found in Intel Apollo Lake, Bay Trail and Braswell + chipsets. Note, however, that the eMMC and SDHCI controllers + of the Apollo Lake variant occasionally lock up due to a + silicon bug (which is independent of running in DDR52 mode). + The only viable workaround for that problem appears to be the + implementation of support for ADMA2 mode in <tt>sdhci(4)</tt> + (currently, <tt>sdhci(4)</tt> supports the encumbered SDMA + mode only, or no DMA at all).</p> + + <p>However, r315598 also already brought in infrastructure and + a fair amount of code for using even faster transfer modes with eMMC + devices and SD cards respectively, i.e., up to HS400ES with eMMC + and the UHS-I modes up to SDR104 with SD cards.</p> + + <p>The intent is to merge these changes back to &os; 10 and 11.</p> + </body> + + <help> + <task>Add support for eMMC HS200, HS400 and HS400ES transfer + modes.</task> + + <task>Add support for SD card UHS-I transfer modes (SDR12 to + SDR104).</task> + + <task>Make <tt>mmcsd(4)</tt> more robust and correctly follow + the relevant specifications for existing features, e.g., + calculate and handle erase timeouts, do a <tt>SEND_STATUS</tt> + when CMD6 is invoked with an R1B response to the extent not + already fixed as part of r315430, get the remainder of the + existing code to properly check and handle return codes, + etc.</task> + </help> + </project> </report>
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