xref: /rk3399_ARM-atf/drivers/console/aarch64/skeleton_console.S (revision aa61368eb554e9910c503f78560153805a2d6859)
1/*
2 * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30#include <asm_macros.S>
31
32	/*
33	 * This file contains a skeleton console implementation that can
34	 * be used as basis for a real console implementation by platforms
35	 * that do not contain PL011 hardware.
36	 */
37
38	.globl	console_core_init
39	.globl	console_core_putc
40	.globl	console_core_getc
41	.globl	console_core_flush
42
43	/* -----------------------------------------------
44	 * int console_core_init(uintptr_t base_addr,
45	 * unsigned int uart_clk, unsigned int baud_rate)
46	 * Function to initialize the console without a
47	 * C Runtime to print debug information. This
48	 * function will be accessed by console_init and
49	 * crash reporting.
50	 * In: x0 - console base address
51	 *     w1 - Uart clock in Hz
52	 *     w2 - Baud rate
53	 * Out: return 1 on success else 0 on error
54	 * Clobber list : x1, x2
55	 * -----------------------------------------------
56	 */
57func console_core_init
58	/* Check the input base address */
59	cbz	x0, core_init_fail
60	/* Check baud rate and uart clock for sanity */
61	cbz	w1, core_init_fail
62	cbz	w2, core_init_fail
63	/* Insert implementation here */
64	mov	w0, #1
65	ret
66core_init_fail:
67	mov	w0, wzr
68	ret
69endfunc console_core_init
70
71	/* --------------------------------------------------------
72	 * int console_core_putc(int c, uintptr_t base_addr)
73	 * Function to output a character over the console. It
74	 * returns the character printed on success or -1 on error.
75	 * In : w0 - character to be printed
76	 *      x1 - console base address
77	 * Out : return -1 on error else return character.
78	 * Clobber list : x2
79	 * --------------------------------------------------------
80	 */
81func console_core_putc
82	/* Check the input parameter */
83	cbz	x1, putc_error
84	/* Insert implementation here */
85	ret
86putc_error:
87	mov	w0, #-1
88	ret
89endfunc console_core_putc
90
91	/* ---------------------------------------------
92	 * int console_core_getc(uintptr_t base_addr)
93	 * Function to get a character from the console.
94	 * It returns the character grabbed on success
95	 * or -1 on error.
96	 * In : x0 - console base address
97	 * Clobber list : x0, x1
98	 * ---------------------------------------------
99	 */
100func console_core_getc
101	cbz	x0, getc_error
102	/* Insert implementation here */
103	ret
104getc_error:
105	mov	w0, #-1
106	ret
107endfunc console_core_getc
108
109	/* ---------------------------------------------
110	 * int console_core_flush(uintptr_t base_addr)
111	 * Function to force a write of all buffered
112	 * data that hasn't been output.
113	 * In : x0 - console base address
114	 * Out : return -1 on error else return 0.
115	 * Clobber list : x0, x1
116	 * ---------------------------------------------
117	 */
118func console_core_flush
119	cbz	x0, flush_error
120	/* Insert implementation here */
121	mov	w0, #0
122	ret
123flush_error:
124	mov	w0, #-1
125	ret
126endfunc console_core_flush
127