On 12/12/2014 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...
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