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Soby Mathew420cc372016-03-24 16:52:40 +00001/*
Antonio Nino Diaz8377ae42017-02-06 16:03:41 +00002 * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
Soby Mathew420cc372016-03-24 16:52:40 +00003 *
dp-armfa3cf0b2017-05-03 09:38:09 +01004 * SPDX-License-Identifier: BSD-3-Clause
Soby Mathew420cc372016-03-24 16:52:40 +00005 */
6#include <asm_macros.S>
7
8 .globl console_init
9 .globl console_uninit
10 .globl console_putc
11 .globl console_getc
Antonio Nino Diaz8377ae42017-02-06 16:03:41 +000012 .globl console_flush
Soby Mathew420cc372016-03-24 16:52:40 +000013
14 /*
15 * The console base is in the data section and not in .bss
16 * even though it is zero-init. In particular, this allows
17 * the console functions to start using this variable before
18 * the runtime memory is initialized for images which do not
19 * need to copy the .data section from ROM to RAM.
20 */
21.section .data.console_base ; .align 2
22 console_base: .word 0x0
23
24 /* -----------------------------------------------
25 * int console_init(uintptr_t base_addr,
26 * unsigned int uart_clk, unsigned int baud_rate)
27 * Function to initialize the console without a
28 * C Runtime to print debug information. It saves
29 * the console base to the data section.
30 * In: r0 - console base address
31 * r1 - Uart clock in Hz
32 * r2 - Baud rate
33 * out: return 1 on success else 0 on error
34 * Clobber list : r1 - r3
35 * -----------------------------------------------
36 */
37func console_init
38 /* Check the input base address */
39 cmp r0, #0
40 beq init_fail
41 ldr r3, =console_base
42 str r0, [r3]
43 b console_core_init
44init_fail:
45 bx lr
46endfunc console_init
47
48 /* -----------------------------------------------
49 * void console_uninit(void)
50 * Function to finish the use of console driver.
51 * It sets the console_base as NULL so that any
52 * further invocation of `console_putc` or
53 * `console_getc` APIs would return error.
54 * -----------------------------------------------
55 */
56func console_uninit
57 mov r0, #0
58 ldr r3, =console_base
59 str r0, [r3]
60 bx lr
61endfunc console_uninit
62
63 /* ---------------------------------------------
64 * int console_putc(int c)
65 * Function to output a character over the
66 * console. It returns the character printed on
67 * success or -1 on error.
68 * In : r0 - character to be printed
69 * Out : return -1 on error else return character.
70 * Clobber list : r1, r2
71 * ---------------------------------------------
72 */
73func console_putc
74 ldr r2, =console_base
75 ldr r1, [r2]
76 b console_core_putc
77endfunc console_putc
78
79 /* ---------------------------------------------
80 * int console_getc(void)
81 * Function to get a character from the console.
82 * It returns the character grabbed on success
83 * or -1 on error.
84 * Clobber list : r0, r1
85 * ---------------------------------------------
86 */
87func console_getc
88 ldr r1, =console_base
89 ldr r0, [r1]
90 b console_core_getc
91endfunc console_getc
Antonio Nino Diaz8377ae42017-02-06 16:03:41 +000092
93 /* ---------------------------------------------
94 * int console_flush(void)
95 * Function to force a write of all buffered
96 * data that hasn't been output. It returns 0
97 * upon successful completion, otherwise it
98 * returns -1.
99 * Clobber list : r0, r1
100 * ---------------------------------------------
101 */
102func console_flush
103 ldr r1, =console_base
104 ldr r0, [r1]
105 b console_core_flush
106endfunc console_flush