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1 | Android Fastboot |
2 | ~~~~~~~~~~~~~~~~ | |
3 | ||
4 | Overview | |
5 | ======== | |
6 | The protocol that is used over USB is described in | |
7 | README.android-fastboot-protocol in same directory. | |
8 | ||
9 | The current implementation does not yet support the flash and erase | |
10 | commands. | |
11 | ||
12 | Client installation | |
13 | =================== | |
14 | The counterpart to this gadget is the fastboot client which can | |
15 | be found in Android's platform/system/core repository in the fastboot | |
16 | folder. It runs on Windows, Linux and even OSX. Linux user are lucky since | |
17 | they only need libusb. | |
18 | Windows users need to bring some time until they have Android SDK (currently | |
19 | http://dl.google.com/android/installer_r12-windows.exe) installed. You | |
20 | need to install ADB package which contains the required glue libraries for | |
21 | accessing USB. Also you need "Google USB driver package" and "SDK platform | |
22 | tools". Once installed the usb driver is placed in your SDK folder under | |
23 | extras\google\usb_driver. The android_winusb.inf needs a line like | |
24 | ||
25 | %SingleBootLoaderInterface% = USB_Install, USB\VID_0451&PID_D022 | |
26 | ||
27 | either in the [Google.NTx86] section for 32bit Windows or [Google.NTamd64] | |
28 | for 64bit Windows. VID and PID should match whatever the fastboot is | |
29 | advertising. | |
30 | ||
31 | Board specific | |
32 | ============== | |
33 | The fastboot gadget relies on the USB download gadget, so the following | |
34 | options must be configured: | |
35 | ||
36 | CONFIG_USBDOWNLOAD_GADGET | |
37 | CONFIG_G_DNL_VENDOR_NUM | |
38 | CONFIG_G_DNL_PRODUCT_NUM | |
39 | CONFIG_G_DNL_MANUFACTURER | |
40 | ||
41 | The fastboot function is enabled by defining CONFIG_CMD_FASTBOOT and | |
42 | CONFIG_ANDROID_BOOT_IMAGE. | |
43 | ||
44 | The fastboot protocol requires a large memory buffer for downloads. This | |
45 | buffer should be as large as possible for a platform. The location of the | |
46 | buffer and size are set with CONFIG_USB_FASTBOOT_BUF_ADDR and | |
47 | CONFIG_USB_FASTBOOT_BUF_SIZE. | |
48 | ||
49 | In Action | |
50 | ========= | |
51 | Enter into fastboot by executing the fastboot command in u-boot and you | |
52 | should see: | |
53 | |GADGET DRIVER: usb_dnl_fastboot | |
54 | ||
55 | On the client side you can fetch the bootloader version for instance: | |
56 | |>fastboot getvar bootloader-version | |
57 | |bootloader-version: U-Boot 2014.04-00005-gd24cabc | |
58 | |finished. total time: 0.000s | |
59 | ||
60 | or initiate a reboot: | |
61 | |>fastboot reboot | |
62 | ||
63 | and once the client comes back, the board should reset. | |
64 | ||
65 | You can also specify a kernel image to boot. You have to either specify | |
66 | the an image in Android format _or_ pass a binary kernel and let the | |
67 | fastboot client wrap the Android suite around it. On OMAP for instance you | |
68 | take zImage kernel and pass it to the fastboot client: | |
69 | ||
70 | |>fastboot -b 0x80000000 -c "console=ttyO2 earlyprintk root=/dev/ram0 | |
71 | | mem=128M" boot zImage | |
72 | |creating boot image... | |
73 | |creating boot image - 1847296 bytes | |
74 | |downloading 'boot.img'... | |
75 | |OKAY [ 2.766s] | |
76 | |booting... | |
77 | |OKAY [ -0.000s] | |
78 | |finished. total time: 2.766s | |
79 | ||
80 | and on the gadget side you should see: | |
81 | |Starting download of 1847296 bytes | |
82 | |........................................................ | |
83 | |downloading of 1847296 bytes finished | |
84 | |Booting kernel.. | |
85 | |## Booting Android Image at 0x81000000 ... | |
86 | |Kernel load addr 0x80008000 size 1801 KiB | |
87 | |Kernel command line: console=ttyO2 earlyprintk root=/dev/ram0 mem=128M | |
88 | | Loading Kernel Image ... OK | |
89 | |OK | |
90 | | | |
91 | |Starting kernel ... |