diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/dreamplug.txt | 77 | ||||
| -rw-r--r-- | doc/sd_card.txt | 42 |
2 files changed, 117 insertions, 2 deletions
diff --git a/doc/dreamplug.txt b/doc/dreamplug.txt index b7f8fc1..af5c0ed 100644 --- a/doc/dreamplug.txt +++ b/doc/dreamplug.txt @@ -1,5 +1,74 @@ -# u-boot Configuration +Kernel and initrd Images +--------------------------- +The bootloader running on the DreamPlug (u-boot) expects raw, uncompressed +kernel and initrd images, usually named uImage and uInitrd. The appropriate +device tree file (dtb) must also be overlaid on the kernel to boot +successfully. + +By default Debian (and the Debian Live build process) generates compressed +images, eg initrd.img-3.2.0-4-kirkwood and vmlinuz-3.2.0-4-kirkwood. + +The scripts ./config/hooks/kernel-image.sh.chroot and +./config/hooks/kernel-image.sh.binary repack the image files and copy them over +to the /live directory in the final binary filesystem. + + +DreamPlug u-Boot Overview +--------------------------- + +Many factory-configured DreamPlugs need their internal u-boot firmware updated +and re-configured to boot from the external 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 (eg, media not ready), but +these can be ignored. + +The desired u-boot configuration is: + + x_bootcmd_usb 'usb start' + baudrate 115200 + bootcmd '${x_bootcmd_usb}; ${x_bootcmd_kernel}; ${x_bootcmd_initrd}; setenv bootargs ${x_bootargs} ${x_bootargs_root} ${x_bootargs_console}; bootm 0x6400000 0x6900000;' + x_bootcmd_kernel ext2load usb 1:1 0x6400000 live/uImage + x_bootcmd_initrd ext2load usb 1:1 0x6900000 live/uInitrd + x_bootargs_root root=/dev/sdb1 rootdelay=4 + x_bootargs console=ttyS0,115200 boot=live config username=torouter hostname=torouter live-media=/dev/sdb1 live-media-timeout=10 debug plainroot + + +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_bootcmd_usb 'usb start' + setenv x_bootcmd_kernel ext2load usb 1:1 0x6400000 live/uImage + setenv x_bootcmd_initrd ext2load usb 1:1 0x6900000 live/uInitrd + setenv x_bootargs_root root=/dev/sdb1 rootdelay=4 + setenv x_bootargs console=ttyS0,115200 boot=live config username=torouter hostname=torouter live-media=/dev/sdb1 live-media-timeout=10 debug plainroot + saveenv + reset + +NOTE: it's possible the above directions are out of date and need to be +refreshed + + +u-boot Configuration +---------------------- You need a recent version of u-boot; search the internet for install/flash instructions. @@ -11,7 +80,11 @@ Use the following boot arguments: set x_bootargs_root root=/dev/sdb1 rootdelay=4 set x_bootargs console=ttyS0,115200 boot=live config username=torouter hostname=torouter live-media=/dev/sdb1 live-media-timeout=10 debug plainroot -# Links + +Background Info, Links +-------------------------- + +See the DreamPlug.jpg photo in this folder. Random notes on the DreamPlug: http://www.madore.org/~david/linux/dreamplug.html diff --git a/doc/sd_card.txt b/doc/sd_card.txt new file mode 100644 index 0000000..9cc34d6 --- /dev/null +++ b/doc/sd_card.txt @@ -0,0 +1,42 @@ + +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. + +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. + +A quick (but inconclusive?) 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 Flash to an SD Card +---------------------------- + +Insert a 4GB+ SD card into to your dev computer (using an adapter if +necessary). ALL DATA AND PARTITIONS WILL BE DELETED. + +Use lsblk to figure out which block device the card is (eg, /dev/sdc). + +Copy over the image (eg, binary.img) with the dd utility: + + $ dd if=binary.img of=/dev/sdc bs=1M + + +Potential Improvements +------------------------- + +Block-aligned partitions may give significantly 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 |