docs/design/console-framework.rst

10 will need to be written for the new UART in TF-A. Current supported UARTs are:
45 runtime output, while the crash console will be used to print the crash log in the
49 These multiple scopes can be useful in many ways, for example:
60 To register a console in TF-A check if the hardware (UART) that is going to be used
62 UART driver API is defined in ``include/drivers/arm/pl011.h``.
64 A skeleton console driver (assembly) is provided in TF-A ``drivers/console/aarch64/
78 to pass an empty ``console_t`` struct which *MUST* be allocated in persistent
81 This function takes a ``console_t`` struct placed in x0 and additional
82 arguments placed in x1 - x7. It returns x0 with either a 0 on failure or 1
89         The ``xxx`` in the function name is replaced with the console driver
91         ``console_pl011_register`` in the driver for pl011.
102 two arguments, a character as int stored in w0, and the ``console_t`` struct pointer
103 stored in x1. It returns w0 with either the character on successs or a negative
136 This ASM function flushes any characters, that are still in the Transmit FIFO but
157 arguments. It will register all of the driver's callbacks in the ``console_t``
163 This macro requires ``console_t`` pointer in x0 and a valid return address in x30.
170 A console can be implemented in pure C, which is much easier than using assembly.
171 Currently there is no C template for implementing a console driver in C but it can
173 for an implementation of a console driver in C.
175 The assembly functions in `Registering a console`_ section can be written in C when
180         support is required then the console driver will need to be written in
181         Assembly (only the putc and flush functions are needed in a crash
188 characters print queue. This can be found in ``drivers/console/multi_console.c``.
190 The multi-console API stores all registered consoles in a struct list ``console_list``.
203 The following functions are defined in the multi_console API.
213 This function adds a console to the ``console_list`` declared in
215 of a specific console in this list. This function is called by the
219 This function always return 1. If the console is already present in the
225         variable declared in ``include/drivers/console.h``.
292         Do not use this function in TF-A release builds, instead use the log
319 This function flushes all the characters pending in the transmit FIFO of the