From c9008213baa2afbfde683f3926b2a63dced6e5a4 Mon Sep 17 00:00:00 2001 From: Jarielle Catbagan Date: Fri, 21 Aug 2015 10:06:00 -0700 Subject: BBB: README: Add section on installing uMon into the eMMC from an SD card --- ports/beagleboneblack/README | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/ports/beagleboneblack/README b/ports/beagleboneblack/README index 6ce6217..eef57b3 100644 --- a/ports/beagleboneblack/README +++ b/ports/beagleboneblack/README @@ -185,6 +185,40 @@ partition of the SD card that was recently formatted as FAT16. The SD card is now ready. +----------------------------------------------------------------------- +eMMC: +----------------------------------------------------------------------- +Booting uMon from the onboard eMMC requires a multiple-step procedure +that will be simplified in the future as the uMon port progresses. + +To transfer a uMon image into the onboard eMMC requires an SD card where +uMon is configured to boot in RAW mode from a known offset. + +With uMon configured to boot in RAW mode from a known offset in the +SD card, the next step is to determine the size of the uMon image in +512-byte blocks. + +With all of this in place, the sequence of uMon commands required to +transfer the uMon image are as follows: + + sd init + mmc init + sd read <# of 512-byte blocks> + mmc write <# of 512-byte blocks> + +With these steps, the uMon image is first transferred into DDR3 RAM +and then written to the eMMC. The reason for this appraoch is that +there is currently no supported mechanism to write the eMMC directly +from an SD card. + +The user must take care to transfer the uMon image in a location in +RAM not currently owned by the uMon image currently in execution. + +As for the final destination in the eMMC, the uMon image must be stored +in a locatation where the internal ROM-bootloader will be able to find +and boot this image. + + ----------------------------------------------------------------------- UART: ----------------------------------------------------------------------- -- cgit v1.2.3