On 12/12/2014 Stephen Warren wrote:
On 12-12-14 10:50 AM, Hans de Goede wrote:
When using usb-keyboard support, typically usb will already get started from preboot. In this case doing it again in the bootcmd is undesirable.
Allow the user of config_distro_bootcmd to indicate that usb is inited in preboot through the user setting BOOTENV_PREBOOT_INITS_USB.
Sorry, I don't recall seeing this whenever it was posted before.
Conceptually this seems fine. One issue it has is with the following sequence:
PREBOOT inits USB, no USB drive found (not plugged in) User CTRL-Cs boot sequence User plugs in USB drive User runs "boot" or "run bootcmd" -> USB not re-detected, so system doesn't boot from USB.
Perhaps the best way to solve this is to have a flag controlling whether BOOTENV_SET_USB_NEED_INIT sets $usb_need_init?
preboot: setenv usb_do_set_usb_need_init false
BOOTENV_SET_USB_NEED_INIT: # Normally unset -> true # In your case, preboot sets this to false if ${usb_do_set_usb_need_init}; then setenv usb_need_init else # Next time $boot is run, this will be unset -> true # so we will re-init USB setenv usb_do_set_usb_need_init # This time through, we skip USB init setenv usb_need_init false endif
Of course, that doesn't solve the problem of the user aborting auto-boot before it's ever run once. Perhaps better would be a flag that BOOTENV_SET_USB_NEED_INIT can use to distinguish auto-boot and manual invocation, i.e.:
preboot: setenv usb_do_set_usb_need_init false
BOOTENV_SET_USB_NEED_INIT: # U-Boot C code sets this appropriatelyL if ${auto_boot}; then # Auto case: Init USB unless preboot set a flag if ${usb_do_set_usb_need_init}; then setenv usb_need_init else # Next time $boot is run, this will be unset -> true # so we will re-init USB setenv usb_do_set_usb_need_init # This time through, we skip USB init setenv usb_need_init false endif else # Manual case: Always init USB setenv usb_need_init endif
Or do we just assume that if the user plugs in a new USB device after boot, they must manually run USB initialization? If so, we cam simplify the existing $usb_need_init a bit...
Looking at all the extra code (and possible bugs / problems that code may introduce), I think that it makes sense to just expect the user to run "usb reset" after plugging in a new device.
Regards,
Hans