source: trunk/tools/bootloader_tsar/boot_tty_driver.c @ 1

Last change on this file since 1 was 1, checked in by alain, 5 years ago

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1///////////////////////////////////////////////////////////////////////////////////
2// File     : boot_tty_driver.c
3// Date     : 18/01/2017
4// Author   : Alain Greiner / Vu Son
5// Copyright (c) UPMC-LIP6
6///////////////////////////////////////////////////////////////////////////////////
7
8#include <boot_config.h>
9#include <boot_tty_driver.h>
10#include <hal_types.h>
11#include <boot_utils.h>
12
13#ifndef SEG_TTY_BASE
14# error "The SEG_TTY_BASE value should be defined in the 'boot_config.h' file"
15#endif
16
17#ifndef IO_CXY
18# error "The IO_CXY value should be defined in the 'boot_config.h' file"
19#endif
20
21
22/****************************************************************************
23 *                            Internal functions.                           *
24 ****************************************************************************/
25
26/****************************************************************************
27 * This function returns the value of the a TTY register.                   *
28 * @ reg    : TTY register to be read.                                      *
29 * @ returns the value stored in 'reg'.                                     *
30 ****************************************************************************/
31static uint32_t boot_tty_get_register( uint32_t reg )
32{
33    cxy_t      cxy = IO_CXY;
34    uint32_t * ptr = (uint32_t *)SEG_TTY_BASE + reg;
35   
36    return boot_remote_lw( XPTR( cxy , ptr ) ); 
37   
38} // boot_tty_get_register()
39
40/****************************************************************************
41 * This function sets a new value to a TTY register.                        *
42 * @ reg    : TTY register to be configured.                                *
43 * @ val    : new value to be written to 'reg'.                             *
44 ****************************************************************************/
45static void boot_tty_set_register( uint32_t reg, 
46                                   uint32_t val )
47{
48    cxy_t      cxy = IO_CXY;
49    uint32_t * ptr = (uint32_t *)SEG_TTY_BASE + reg;
50
51    boot_remote_sw( XPTR( cxy , ptr ) , val ); 
52
53} // boot_tty_set_register()
54
55/****************************************************************************
56 *                           Driver API functions.                          *
57 ****************************************************************************/
58
59int boot_tty_write( char    * buf,
60                    uint32_t  nbytes )
61{
62    uint32_t nb_printed;    /* Iterator for printing loop.              */
63    uint32_t nb_test;       /* Iterator for retry loop.                 */
64    uint32_t error;         /* Used to detect if an error occurs.       */
65
66    /* Printing to the boot TTY terminal. */
67    for (nb_printed = 0; nb_printed < nbytes; nb_printed++)
68    {
69        // Polling the TTY driver status.
70        if ((boot_tty_get_register(TTY_STATUS) & TTY_WRITE_BUSY))
71        {
72            // TTY_WRITE_BUSY bit of TTY_STATUS register is set, keeps polling.
73            error = 1;
74            for (nb_test = 0; nb_test < 10000; nb_test++)
75                if ((boot_tty_get_register(TTY_STATUS) & TTY_WRITE_BUSY) == 0)
76                {
77                    error = 0;
78                    break;
79                }
80
81            // Reporting an error if the TTY_WRITE_BUSY bit is still set after
82            // 10000 retries.
83            if (error)
84                return -1;
85        }
86
87        // Writing a character to the boot TTY terminal.
88        // Special treatment for a newline: Carriage Return before Line Feed.
89        if (buf[nb_printed] == '\n')
90            boot_tty_set_register(TTY_WRITE, (uint32_t)'\r');
91        boot_tty_set_register(TTY_WRITE, (uint32_t)buf[nb_printed]);
92    }
93
94    return 0;
95
96} // boot_tty_write()
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