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| author | Vicente <vicencb@gmail.com> | 2012-10-09 00:55:20 +0200 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2012-11-16 15:32:31 +0100 |
| commit | 6b4dc4d4f128bd22df4d022ad37285ce4858e1e8 (patch) | |
| tree | dd66fc53750274c211dd78994732701de9ad7608 /Documentation | |
| parent | 7b8a200154be38bd54ce4fc291a5a7904e5d33f2 (diff) | |
| download | barebox-6b4dc4d4f128bd22df4d022ad37285ce4858e1e8.tar.gz barebox-6b4dc4d4f128bd22df4d022ad37285ce4858e1e8.tar.xz | |
omap4: add support for booting cpu from usb
Signed-off-by: Vicente <vicencb@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/oamp4_usb_booting.txt | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/oamp4_usb_booting.txt b/Documentation/oamp4_usb_booting.txt new file mode 100644 index 0000000000..f0d45a2aa1 --- /dev/null +++ b/Documentation/oamp4_usb_booting.txt @@ -0,0 +1,27 @@ +-------------- omap4_usb_booting -------------- + +omap4 processors have support for booting from the usb port. To be able to fully +use this feature you will need to enable the following: + OMAP4_USBBOOT + This CONFIG_ option adds the required infrastructure. + DRIVER_SERIAL_OMAP4_USBBOOT + This adds console support over the same usb port used for booting. + FS_OMAP4_USBBOOT + This adds filesystem support over the same usb port used for booting. + +To send the bootloader to the processor, execute the utility omap4_usbboot which +can be found in the scripts subdirectory. +omap4_usbboot takes two parameters: + the bootloader image + a directory name which will be the root for the guest system +Once omap4_usbboot is running it will wait for enumeration of the omap4 cpu on +the host usb subsystem. Then power on or reset the cpu with the correct sys_boot +or SAR memory configuration. + +If everything works, barebox's first stage will boot and afterwards it will load +the second stage found at "/barebox.bin". +Barebox's second stage will still have access to the usb filesystem, so an +initrd and a zImage can be loaded. + +Overall this procedure frees the developer of continously be changing the SD +card or other boot media from host to target. |