Support for eMMC flash and Faster SD Card Modes

From owner-svn-doc-all@freebsd.org Thu Apr 20 04:06:35 2017 Return-Path: Delivered-To: svn-doc-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B2306D47EC5; Thu, 20 Apr 2017 04:06:35 +0000 (UTC) (envelope-from bjk@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8D5D81FD; Thu, 20 Apr 2017 04:06:35 +0000 (UTC) (envelope-from bjk@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v3K46YDN075842; Thu, 20 Apr 2017 04:06:34 GMT (envelope-from bjk@FreeBSD.org) Received: (from bjk@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v3K46Ywf075841; Thu, 20 Apr 2017 04:06:34 GMT (envelope-from bjk@FreeBSD.org) Message-Id: <201704200406.v3K46Ywf075841@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: bjk set sender to bjk@FreeBSD.org using -f From: Benjamin Kaduk Date: Thu, 20 Apr 2017 04:06:34 +0000 (UTC) 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 X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-all@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "SVN commit messages for the entire doc trees \(except for " user" , " projects" , and " translations" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 Apr 2017 04:06:35 -0000 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 @@ Submit the remaining fixes and drivers. + + + Support for eMMC flash and Faster SD Card Modes + + + + + Marius + Strobl + + marius@FreeBSD.org + + + + +

In r315430, support for eMMC partitions has been added to + mmc(4) and mmcsd(4) in &os; 12. Besides the + user data area, i.e., the default partition, eMMC v4.41 and + later devices can additionally provide up to:

+ +

1 enhanced user data area partition
2 boot partitions
1 RPMB (Replay Protected Memory Block) partition
4 general purpose partitions (optionally with a enhanced + or extended attribute)

+ +

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.

+ +

In order to be able to partition eMMC devices, r315430 also + added a Linux-compatible IOCTL interface to mmcsd(4). + This allows for using the GNU mmc-utils (found in ports + as sysutils/mmc-utils) on &os;. Besides partitioning + eMMC devices, the mmc 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.

+ +

CAVEAT EMPTOR: Partitioning eMMC devices is a one-time + operation.

+ +

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 mmc(4) + and sdhci(4) 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.

+ +

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 sdhci(4) + (currently, sdhci(4) supports the encumbered SDMA + mode only, or no DMA at all).

+ +

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.

+ +

The intent is to merge these changes back to &os; 10 and 11.

+ + + + Add support for eMMC HS200, HS400 and HS400ES transfer + modes. + + Add support for SD card UHS-I transfer modes (SDR12 to + SDR104). + + Make mmcsd(4) more robust and correctly follow + the relevant specifications for existing features, e.g., + calculate and handle erase timeouts, do a SEND_STATUS + 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. + +