1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2023 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <unistd.h>
39 #include "sparc-semihost.h"
40
41 typedef volatile uint8_t vuint8_t;
42 typedef volatile uint32_t vuint32_t;
43
44 struct apbuart {
45 vuint32_t data;
46 vuint32_t status;
47 vuint32_t control;
48 };
49
50 #ifdef __GNUC__
51 #pragma GCC diagnostic ignored "-Wpragmas"
52 #pragma GCC diagnostic ignored "-Wunknown-warning-option"
53 /* 'bsize' is used directly with malloc/realloc which confuses -fanalyzer */
54 #pragma GCC diagnostic ignored "-Warray-bounds"
55 #endif
56
57 /* leon3 serial port */
58 #define uart (*((struct apbuart *) 0x80000100))
59
60 /* UART status register fields */
61 #define UART_DATA_READY (1 << 0)
62 #define UART_TRANSMIT_SHIFT_EMPTY (1 << 1)
63 #define UART_TRANSMIT_FIFO_EMPTY (1 << 2)
64 #define UART_BREAK_RECEIVED (1 << 3)
65 #define UART_OVERRUN (1 << 4)
66 #define UART_PARITY_ERROR (1 << 5)
67 #define UART_FRAMING_ERROR (1 << 6)
68 #define UART_TRANSMIT_FIFO_HALF (1 << 7)
69 #define UART_RECEIVE_FIFO_HALF (1 << 8)
70 #define UART_TRANSMIT_FIFO_FULL (1 << 9)
71 #define UART_RECEIVE_FIFO_FULL (1 << 10)
72
73 /* UART control register fields */
74 #define UART_RECEIVE_ENABLE (1 << 0)
75 #define UART_TRANSMIT_ENABLE (1 << 1)
76 #define UART_RECEIVE_INTERRUPT (1 << 2)
77 #define UART_TRANSMIT_INTERRUPT (1 << 3)
78 #define UART_PARITY_SELECT (1 << 4)
79 #define UART_PARITY_ENABLE (1 << 5)
80 #define UART_FLOW_CONTROL (1 << 6)
81 #define UART_LOOPBACK (1 << 7)
82 #define UART_EXTERNAL_CLOCK (1 << 8)
83 #define UART_RECEIVE_FIFO_INTERRUPT (1 << 9)
84 #define UART_TRANSMIT_FIFO_INTERRUPT (1 << 10)
85 #define UART_FIFO_DEBUG_MODE (1 << 11)
86 #define UART_OUTPUT_ENABLE (1 << 12)
87 #define UART_FIFO_AVAILABLE (1 << 31)
88
89 int
sparc_putc(char c,FILE * file)90 sparc_putc(char c, FILE *file)
91 {
92 (void) file;
93 uart.control |= UART_TRANSMIT_ENABLE;
94 while ((uart.status & UART_TRANSMIT_FIFO_FULL) != 0)
95 ;
96 uart.data = (uint8_t) c;
97 return (unsigned char) c;
98 }
99
100 #ifdef TINY_STDIO
101
102 static int
sparc_getc(FILE * file)103 sparc_getc(FILE *file)
104 {
105 (void) file;
106 uart.control |= UART_RECEIVE_ENABLE;
107 while ((uart.status & UART_DATA_READY) == 0)
108 ;
109 return (unsigned char) uart.data;
110 }
111
112 static FILE __stdio = FDEV_SETUP_STREAM(sparc_putc, sparc_getc, NULL, _FDEV_SETUP_RW);
113
114 #ifdef __strong_reference
115 #define STDIO_ALIAS(x) __strong_reference(stdin, x);
116 #else
117 #define STDIO_ALIAS(x) FILE *const x = &__stdio;
118 #endif
119
120 FILE *const stdin = &__stdio;
121 STDIO_ALIAS(stdout);
122 STDIO_ALIAS(stderr);
123
124 #endif
125
