On Thu, Feb 18, 2021 at 1:10 AM ha ppay <andocn...@gmail.com> wrote: > > > Hi Everyone. > I'm collecting information to get even faster boot times, > I have 2 questions. > It is written that it is possible to boot from MMC (8bit mode) (18.1.1 MMCHS > Features) using MMC mode with TRM of am335x. > - Clock support > -96-MHz functional clock source input > -up to 384Mbit/sec (48MByte/sec) in MMC mode 8-bit data transfer > -up to 192Mbit/sec (24MByte/sec) in High-Speed SD mode 4-bit data transfer > -up to 24Mbit/sec (3MByte/sec) in Default SD mode 1-bit data transfer > > Also, the SD_CON register DW8 Field has a flag for it. > I expect this setting to start up much faster. > In BBB, how do I set it to 8bit mode and how do I set the frequency to > 384Mbit / sec (is it mmc_clk/clock-div in Devicetree?)?
It's already in 8-bit mode.. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/am335x-boneblack-common.dtsi#n23 &mmc2 { vmmc-supply = <&vmmcsd_fixed>; pinctrl-names = "default"; pinctrl-0 = <&emmc_pins>; bus-width = <8>; status = "okay"; non-removable; }; Regards, -- Robert Nelson https://rcn-ee.com/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAOCHtYhuU-P8JNE45CudLK2TUn3-ZW0ePhfZx_p%2BH7i0HGzuUw%40mail.gmail.com.
