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Soby Mathew7abebe82016-08-08 12:38:52 +01001/*
Antonio Nino Diaz8377ae42017-02-06 16:03:41 +00002 * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
Soby Mathew7abebe82016-08-08 12:38:52 +01003 *
dp-armfa3cf0b2017-05-03 09:38:09 +01004 * SPDX-License-Identifier: BSD-3-Clause
Soby Mathew7abebe82016-08-08 12:38:52 +01005 */
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 Mathew7abebe82016-08-08 12:38:52 +010013
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 3
22 console_base: .quad 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: x0 - console base address
31 * w1 - Uart clock in Hz
32 * w2 - Baud rate
33 * out: return 1 on success else 0 on error
34 * Clobber list : x1 - x4
35 * -----------------------------------------------
36 */
37func console_init
38 /* Check the input base address */
39 cbz x0, init_fail
40 adrp x3, console_base
41 str x0, [x3, :lo12:console_base]
42 b console_core_init
43init_fail:
44 ret
45endfunc console_init
46
47 /* -----------------------------------------------
48 * void console_uninit(void)
49 * Function to finish the use of console driver.
50 * It sets the console_base as NULL so that any
51 * further invocation of `console_putc` or
52 * `console_getc` APIs would return error.
53 * -----------------------------------------------
54 */
55func console_uninit
56 mov x0, #0
57 adrp x3, console_base
58 str x0, [x3, :lo12:console_base]
59 ret
60endfunc console_uninit
61
62 /* ---------------------------------------------
63 * int console_putc(int c)
64 * Function to output a character over the
65 * console. It returns the character printed on
66 * success or -1 on error.
67 * In : x0 - character to be printed
68 * Out : return -1 on error else return character.
69 * Clobber list : x1, x2
70 * ---------------------------------------------
71 */
72func console_putc
73 adrp x2, console_base
74 ldr x1, [x2, :lo12:console_base]
75 b console_core_putc
76endfunc console_putc
77
78 /* ---------------------------------------------
79 * int console_getc(void)
80 * Function to get a character from the console.
81 * It returns the character grabbed on success
82 * or -1 on error.
83 * Clobber list : x0, x1
84 * ---------------------------------------------
85 */
86func console_getc
87 adrp x1, console_base
88 ldr x0, [x1, :lo12:console_base]
89 b console_core_getc
90endfunc console_getc
Antonio Nino Diaz8377ae42017-02-06 16:03:41 +000091
92 /* ---------------------------------------------
93 * int console_flush(void)
94 * Function to force a write of all buffered
95 * data that hasn't been output. It returns 0
96 * upon successful completion, otherwise it
97 * returns -1.
98 * Clobber list : x0, x1
99 * ---------------------------------------------
100 */
101func console_flush
102 adrp x1, console_base
103 ldr x0, [x1, :lo12:console_base]
104 b console_core_flush
105endfunc console_flush