file-list: support special 'auto', 'block' specifiers

Best practice is for each board to populate $global.system.partitions
or $global.fastboot.partitions with a string exporting its flashable
devices in a descriptive manner, e.g. "/dev/mmc0(eMMC),/dev/mmc1(SD)".

This often goes into BSPs though, so upstream boards are left without
default partitions, making use a bit cumbersome. Make this easier
by providing two new magic specifiers:

  - block: exports all registered block devices (e.g. eMMC and SD)
  - auto:  currently equivalent to "block". May be extended
           to EEPROMs, raw MTD and UBI in future

This makes it easy to export devices on any board:

  usbgadget -A auto -b

or

  usbgadget -S auto,/tmp/fitimage(fitimage)c

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20230609075229.1093397-2-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 16 insertions, 0 deletions

diff --git a/Documentation/user/usb.rst b/Documentation/user/usb.rst
index f2f57ead98..eaee342956 100644
--- a/Documentation/user/usb.rst
+++ b/Documentation/user/usb.rst
@@ -73,6 +73,22 @@ Example:
 
   /dev/nand0.barebox.bb(barebox)sr,/kernel(kernel)rc
 
+Board code authors are encouraged to provide a default environment containing
+partitions with descriptive names. For boards where this is not specified,
+there exist a number of **partition** specifiers for automatically generating entries:
+
+* ``block`` exports all registered block devices (e.g. eMMC and SD)
+* ``auto``  currently equivalent to ``block``. May be extended to other flashable
+            devices, like EEPROMs, MTD or UBI volumes in future
+
+Example usage of exporting registered block devices, barebox update
+handlers and a single file that is created on flashing:
+
+.. code-block:: sh
+
+     detect -a # optional. Detects everything, so auto can register it
+     usbgadget -A auto,/tmp/fitimage(fitimage)c -b
+
 DFU
 ^^^