Date: Mon, 3 Dec 2012 23:51:47 +0900 From: "Daisuke Aoyama" <aoyama@peach.ne.jp> To: <Ralf.Wenk@hs-karlsruhe.de>, <freebsd-arm@freebsd.org> Subject: Re: FreeBSD on Raspberry Pi 512MB (with U-Boot + ubldr) Message-ID: <B3D30A45699E443399D7CB112082356B@ad.peach.ne.jp> In-Reply-To: <E1TfWh4-00BZ82-Is@smtp.hs-karlsruhe.de> References: <3988C1622A974F19A9D3888F0334FF10@ad.peach.ne.jp> <50B8058C.9030909@bluezbox.com> <E1TfWh4-00BZ82-Is@smtp.hs-karlsruhe.de>
next in thread | previous in thread | raw e-mail | index | archive | help
>>> BTW, SDHCI is not yet stable? >> >> There is one issue with setting SDHCI clock. I'll commit fix later today. > > > I like to share some information about the SD card reading speed. > > While exchanging the old boot sequence with then new one I once booted > with the new boot sequence but without an /boot/loader.rc file. > > The reading speed achieved with > dd if=/dev/mmcsd0 of=/dev/null bs=1m count=100 > from the SD card was 10 Mbyte/sec. > > After creating the file with "echo 'fdt addr 0x100' > /boot/loader.rc" > and rebooting the reading speed achieved from the SD card was down to > 2.8 Mbyte/sec. > > Although the SDHCI frequency was shown on the second boot as double high > as > on the first (100MHz versus 50MHz) the reading speed was much lower. > I think the cause was the mmcsd bus bit width which was reported as 4 at > the first and as 1 at the second boot. At this time, it must be 50. if use 100MHz, some cards cant be used anymore. Howerver, probably 4bit transfer is OK. -- Daisuke Aoyama
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?B3D30A45699E443399D7CB112082356B>