USB commands in U-boot

[U-boot: v2013.04]

[Author: Bo Shen <voice.shen@gmail.com>]

1. Use (help information)

U-boot> USB-USB sub-system usage: USB start-start (SCAN) USB controllerusb reset-Reset (rescan) USB controllerusb stop [f]-Stop USB [f] = force stopusb tree-show USB device treeusb info [Dev]-show available USB devicesusb storage-Show Details of USB storage devicesusb Dev [dev]-show or set current USB storage deviceusb part [Dev]-print Partition Table of one or all USB storage devicesusb read addr blk # CNT-read 'cnt 'blocks starting at Block' BLK # 'to memory address 'addr 'usb write addr blk # CNT-write 'cnt 'blocks starting at Block 'blk #' from memory address 'addr'

1.1usb start/USB Reset

U-boot> USB start (re) Start USB... usb0: scanning bus 0 for devices... 2 USB device (s) found scanning USB for storage devices... 1 storage device (s) found

USB tree 1.2

U-boot> USB treeusb Device Tree: 1 hub (12 Mb/s, 0mA) | OHCI root hub | +-2 mass storage (12 Mb/s, 200mA) Kingston datatraveler G3 001372982955ebc0c5ab0019

1.3 USB Info (USB info 1/USB Info 2)

U-boot> USB info 1: hub, USB revision 1.10-OHCI root hub-class: hub-packetsize: 8 deployments: 1-vendor: 0x0000 product 0x0000 version 0.0 configuration: 1-Interfaces: 1 self powered 0mA interface: 0-Alternate setting 0, endpoints: 1-class hub-endpoint 1 in interrupt maxpacket 2 interval 255 Ms 2: Mass Storage, USB revision 2.0-Kingston datatraveler G3 001372982955ebc0c5ab0019-class: (from interface) Mass Storage-packetsize: 64 deployments: 1-vendor: 0x0930 product 0x6545 version 1.0 configuration: 1-Interfaces: 1 bus powered 200mA interface: 0-Alternate setting 0, endpoints: 2-class mass storage, Transp. SCSI, bulk only-endpoint 1 in bulk maxpacket 64-endpoint 2 out bulk maxpacket 641.4 USB Devu-boot> USB Dev USB device 0: Vendor: Kingston Rev: pmap prod: datatraveler G3 type: removable hard disk capacity: 7441.6 MB = 7.2 GB (15240576x512)

2. Source Code Analysis

<Common/cmd_usb.c>

2.1 USB start/USB reset command code execution

[Strncmp (argv [1], "Start", 5) = 0]/[strncmp (argv [1], "reset", 5) = 0] --> usb_stop () --> usb_init () --> usb_stor_scan (1) (config_usb_storage) --> usb_host_eth_scan (1) (config_usb_host_ether)
--> Drv_usb_kbd_init () (config_usb_keyboard) --> return 0;

2.2 USB Stop command code execution

[Strncmp (argv [1], "stop", 4) = 0] --> (config_usb_keyboard) [argc = 2] --> usb_kbd_deregister () --> usb_stop --> return 0;

[Strncmp (argv [1], "stop", 4) = 0] --> (config_usb_keyboard) [argc! = 2] --> console_assign (stdin, "serial") --> usb_kbd_deregister () --> usb_stop --> return 0;