+ COUNTER_FREQUENCY
+ Generic timer clock source frequency.
+
+ COUNTER_FREQUENCY_REAL
+ Generic timer clock source frequency if the real clock is
+ different from COUNTER_FREQUENCY, and can only be determined
+ at run time.
+
+ NOTE: The following can be machine specific errata. These
+ do have ability to provide rudimentary version and machine
+ specific checks, but expect no product checks.
+ CONFIG_ARM_ERRATA_798870
+ CONFIG_ARM_ERRATA_801819
+
+- Tegra SoC options:
+ CONFIG_TEGRA_SUPPORT_NON_SECURE
+
+ Support executing U-Boot in non-secure (NS) mode. Certain
+ impossible actions will be skipped if the CPU is in NS mode,
+ such as ARM architectural timer initialization.
+
+- Driver Model
+ Driver model is a new framework for devices in U-Boot
+ introduced in early 2014. U-Boot is being progressively
+ moved over to this. It offers a consistent device structure,
+ supports grouping devices into classes and has built-in
+ handling of platform data and device tree.
+
+ To enable transition to driver model in a relatively
+ painful fashion, each subsystem can be independently
+ switched between the legacy/ad-hoc approach and the new
+ driver model using the options below. Also, many uclass
+ interfaces include compatibility features which may be
+ removed once the conversion of that subsystem is complete.
+ As a result, the API provided by the subsystem may in fact
+ not change with driver model.
+
+ See doc/driver-model/README.txt for more information.
+
+ CONFIG_DM
+
+ Enable driver model. This brings in the core support,
+ including scanning of platform data on start-up. If
+ CONFIG_OF_CONTROL is enabled, the device tree will be
+ scanned also when available.
+
+ CONFIG_CMD_DM
+
+ Enable driver model test commands. These allow you to print
+ out the driver model tree and the uclasses.
+
+ CONFIG_DM_DEMO
+
+ Enable some demo devices and the 'demo' command. These are
+ really only useful for playing around while trying to
+ understand driver model in sandbox.
+
+ CONFIG_SPL_DM
+
+ Enable driver model in SPL. You will need to provide a
+ suitable malloc() implementation. If you are not using the
+ full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
+ consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
+ must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
+ In most cases driver model will only allocate a few uclasses
+ and devices in SPL, so 1KB should be enable. See
+ CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
+ it.
+
+ CONFIG_DM_SERIAL
+
+ Enable driver model for serial. This replaces
+ drivers/serial/serial.c with the serial uclass, which
+ implements serial_putc() etc. The uclass interface is
+ defined in include/serial.h.
+
+ CONFIG_DM_GPIO
+
+ Enable driver model for GPIO access. The standard GPIO
+ interface (gpio_get_value(), etc.) is then implemented by
+ the GPIO uclass. Drivers provide methods to query the
+ particular GPIOs that they provide. The uclass interface
+ is defined in include/asm-generic/gpio.h.
+
+ CONFIG_DM_SPI