arm-trusted-firmware/drivers/console/aarch64/skeleton_console.S

103 lines
2.8 KiB
ArmAsm

/*
* Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <asm_macros.S>
/*
* This file contains a skeleton console implementation that can
* be used as basis for a real console implementation by platforms
* that do not contain PL011 hardware.
*/
.globl console_core_init
.globl console_core_putc
.globl console_core_getc
.globl console_core_flush
/* -----------------------------------------------
* int console_core_init(uintptr_t base_addr,
* unsigned int uart_clk, unsigned int baud_rate)
* Function to initialize the console without a
* C Runtime to print debug information. This
* function will be accessed by console_init and
* crash reporting.
* In: x0 - console base address
* w1 - Uart clock in Hz
* w2 - Baud rate
* Out: return 1 on success else 0 on error
* Clobber list : x1, x2
* -----------------------------------------------
*/
func console_core_init
/* Check the input base address */
cbz x0, core_init_fail
/* Check baud rate and uart clock for sanity */
cbz w1, core_init_fail
cbz w2, core_init_fail
/* Insert implementation here */
mov w0, #1
ret
core_init_fail:
mov w0, wzr
ret
endfunc console_core_init
/* --------------------------------------------------------
* int console_core_putc(int c, uintptr_t base_addr)
* Function to output a character over the console. It
* returns the character printed on success or -1 on error.
* In : w0 - character to be printed
* x1 - console base address
* Out : return -1 on error else return character.
* Clobber list : x2
* --------------------------------------------------------
*/
func console_core_putc
/* Check the input parameter */
cbz x1, putc_error
/* Insert implementation here */
ret
putc_error:
mov w0, #-1
ret
endfunc console_core_putc
/* ---------------------------------------------
* int console_core_getc(uintptr_t base_addr)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* In : x0 - console base address
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_core_getc
cbz x0, getc_error
/* Insert implementation here */
ret
getc_error:
mov w0, #-1
ret
endfunc console_core_getc
/* ---------------------------------------------
* int console_core_flush(uintptr_t base_addr)
* Function to force a write of all buffered
* data that hasn't been output.
* In : x0 - console base address
* Out : return -1 on error else return 0.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_core_flush
cbz x0, flush_error
/* Insert implementation here */
mov w0, #0
ret
flush_error:
mov w0, #-1
ret
endfunc console_core_flush