sd card refactor

2 files changed, 89 insertions, 0 deletions

diff --git a/doc/sd_card.txt b/doc/sd_card.txt
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+
+torouter is intended to boot and run from an SD. it could theoretically also
+run from an internal microSD card, a USB stick, or an eSATA drive, but
+specifying use of the SD card makes support, development, and documentation
+easier. the SD card can easily be popped out of the router and reflashed with a
+new image.
+
+The SD card should be at least 2GB in size and support reasonable read/write
+speeds, so probably a "class 6" quality card, which can be ##########
+
+you really should get a decent card: there can be an order of magnitude
+difference in performance between a cheap card and a fast card. 
+
+quick (but shady?) way to check read and write card performance on a
+high-performance machine: 
+
+    $ # unmount the card for read test
+    $ hdparm -t /dev/sdb    # iff /dev/sdb is the card
+    $ # mount the card for write test
+    $ dd count=10 bs=1M if=/dev/urandom of=/mnt/disktest
+
+
+HOWTO Prepare an SD Card for building (using debian)
+--------------------------------------------------------
+
+Insert a 4GB+ SD card into to your dev computer (using an adapter if necessary).
+
+Use lsblk to figure out which block device the card is (eg, /dev/sdc).
+
+Use gparted (as root) to create two logical paritions: first, a 128MB FAT32
+(msdos) boot partition, and second an ext4 root partition using the remainder
+of the space.
+
+Once the paritions are created, and you have confirmed that the partitions
+exist and are in the correct order (eg, small boot on /dev/sdc1, rootfs on
+/dev/sdc2), you are ready to copy over a fresh build using
+freedom-maker/copy2card.sh and then create an image file using
+freedom-maker/copy2img.sh.
+
+Optionally, follow these directions to generate block-aligned partitions for
+better write performance:
+
+http://linux-howto-guide.blogspot.de/2009/10/increase-usb-flash-drive-write-speed.html
+http://www.olpcnews.com/forum/index.php?topic=4993.0
diff --git a/doc/uboot.txt b/doc/uboot.txt
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+
+Factory-configured DreamPlugs need their internal u-boot firmware updated and
+re-configured to boot from the SD card. 
+
+You may want to remove the internal microSD card for the sake of simplicity.
+This will result in u-boot and linux boot warnings, but these can be ignored.
+
+The desired u-boot configuration is: 
+
+    baudrate=115200
+    bootargs=console=ttyS0,115200 root=/dev/sdb2 rootdelay=10
+    bootcmd=${x_bootcmd_usb}; ${x_bootcmd_kernel}; ${x_bootcmd_initrd}; setenv bootargs ${x_bootargs} ${x_bootargs_root}; bootm 0x6400000 0x6900000;
+    x_bootargs=console=ttyS0,115200
+    x_bootargs_root=root=/dev/sdb2 rootdelay=10
+    x_bootcmd_initrd=fatload usb 1:1 0x6900000 uInitrd
+    x_bootcmd_kernel=fatload usb 1:1 0x6400000 uImage
+    x_bootcmd_usb=usb start
+
+HOWTO: flash and configure u-boot
+-----------------------------------
+
+The default SD card images include the u-boot firmware required to boot from
+the card. Insert a flashed SD card into the DreamPlug and connect with screen:
+
+    $ screen /dev/ttyUSB0 115200
+
+Power up the DreamPlug and quickly press enter in the screen session to
+interrupt boot. Then enter the following commands into the running u-boot
+session (change the last argument of the 'sf write' line, in hex, if the .kwb
+file size changes from exactly 196076 bytes):
+
+    usb start
+    fatload usb 1 0x6400000 uboot.2012.04.01-2_armel.kwb
+    sf probe 0
+    sf erase 0x0 0x80000
+    sf write 0x6400000 0x0 0x2fdec
+    setenv baudrate 115200
+    setenv bootcmd '${x_bootcmd_usb}; ${x_bootcmd_kernel}; ${x_bootcmd_initrd}; setenv bootargs ${x_bootargs} ${x_bootargs_root} ${x_bootargs_console}; bootm 0x6400000 0x6900000;'
+    setenv x_bootargs_console 'ttyS0,115200'
+    setenv x_bootargs_root 'root=/dev/sdb2 rootdelay=10'
+    setenv x_bootcmd_initrd 'fatload usb 1:1 0x6900000 uInitrd'
+    setenv x_bootcmd_kernel 'fatload usb 1:1 0x6400000 uImage'
+    setenv x_bootcmd_usb 'usb start'
+    saveenv
+    reset