diff --git a/configs/sabre-6quad/README.txt b/configs/sabre-6quad/README.txt index b8388503e05..b72111fc6d5 100644 --- a/configs/sabre-6quad/README.txt +++ b/configs/sabre-6quad/README.txt @@ -194,8 +194,8 @@ board next to the HDMI connect) and Android will boot. But we need some other way to boot NuttX. Here are some things that I have experimented with. -Building U-Boot (Attempt #1) ----------------------------- +Building U-Boot (Failed Attempt #1) +----------------------------------- I have been unsuccessful getting building a working version of u-boot from scratch. It builds, but it does not run. Here are the things I did: @@ -237,8 +237,8 @@ scratch. It builds, but it does not run. Here are the things I did: sudo, or do a chmod a+w as root on the SD card device node to grant permissions to users. -Using the Other SD Card Slot (Attempt #2) ------------------------------------------ +Using the Other SD Card Slot (Failed Attempt #2) +------------------------------------------------ Another option is to use the version u-boot that came on the 8GB but put NuttX on another SD card inserted in the other SD card slot at the opposite @@ -248,8 +248,8 @@ To make a long story short: This doesn't work. As far as I can tell, U-Boot does not support any other other SC card except for mmc 2 with is the boot SD card slot. -Replace Boot SD Card (Attempt #3) ---------------------------------- +Replace Boot SD Card (Successful Attempt #3) +-------------------------------------------- What if you remove the SD card after U-boot has booted, then then insert another SD card containing the nuttx.bin image? @@ -281,17 +281,50 @@ another SD card containing the nuttx.bin image? 7. Then we can boot NuttX off the rescanned SD card: - MX6Q SABRESD U-Boot > fatload mmc 2 0x20010000 nuttx.bin + MX6Q SABRESD U-Boot > fatload mmc 2 0x10800000 nuttx.bin reading nuttx.bin 87260 bytes read - MX6Q SABRESD U-Boot > go 0x2001040 - ## Starting application at 0x02001040 ... + MX6Q SABRESD U-Boot > go 0x10800040 + ## Starting application at 0x10800040 ... - MX6Q SABRESD U-Boot > + That seems to work okay. - That seems to work okay and this is more than enough of this kind of - thing for a day. +Use the FAT Partition on the 8GB SD Card (Untested Idea #4) +----------------------------------------------------------- + +Partition 4 on the SD card is an Android FAT file system. So one thing you +could do would be put the nuttx.bin file on that partition, then boot like: + + MX6Q SABRESD U-Boot > fatload mmc 2:4 0x10800000 nuttx.bin + +SD Card Image Copy (Successful Attempt #5) +------------------------------------- + +You can use the 'dd' command to copy the first couple of megabytes from the +8GB SD card and copy that to another SD card. You then have to use 'fdisk' +to fix the partition table and to add a single FAT16 partition at an offset +of 1MB or so. + +1. Insert the 8GB boot SD card into your PC: Copy the first 2Mb from the SD + card to a file: + + $ dd if=/dev/sdh of=sdh.img bs=512 count=4096 + +2. Remove the 8GB boot SD card and replace it with a fresh SD card. Copy the + saved file to the first the new SD card: + + $ dd of=/dev/sdh if=sdh.img bs=512 count=4096 + +3. Then make a FAT16 partition at the end of the SD card. You will also need + to format the partion for FAT. + +4. You can put nuttx.bin here and then boot very simply with: + + MX6Q SABRESD U-Boot > fatload mmc 2:1 0x10800000 nuttx.bin + MX6Q SABRESD U-Boot > go 0x10800040 + +A little hokey, but not such a bad solution. Configuration sub-directories -----------------------------