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/* Copyright 2019 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "config.h"
#include "console.h"
#include "timer.h"
#include "uart.h"
#include "util.h"
#include "watchdog.h"
/*
* Microseconds time to drain entire UART_TX console buffer at 115200 b/s, 10
* bits per character.
*/
#define BUFFER_DRAIN_TIME_US (1000000UL * 10 * CONFIG_UART_TX_BUF_SIZE / 115200)
/*
* Generate a stream of characters on the UART console.
*
* The stream is an ever incrementing pattern of characters from the following
* set: 0..9A..Za..z.
*
* The two optional integer command line arguments work as follows:
*
* argv[1] - reset the pattern after this many characters have been printed.
* Setting this value to the width of the terminal window results
* in a very regular stream showing on the terminal, where it is
* easy to observe disruptions.
* argv[2] - limit number of printed characters to this amount. If not
* specified - keep printing indefinitely.
*
* Hitting 'x' on the keyboard stops the generator.
*/
static int command_chargen(int argc, char **argv)
{
int wrap_value = 0;
int wrap_counter = 0;
uint8_t c;
uint32_t seq_counter = 0;
uint32_t seq_number = 0;
timestamp_t prev_watchdog_time;
while (uart_getc() != -1)
; /* Drain received characters, if any. */
if (argc > 1)
wrap_value = atoi(argv[1]);
if (argc > 2)
seq_number = atoi(argv[2]);
c = '0';
prev_watchdog_time = get_time();
while (uart_getc() != 'x') {
timestamp_t current_time;
while (uart_buffer_full()) {
/*
* Let's sleep enough time to drain half of TX
* buffer.
*/
usleep(BUFFER_DRAIN_TIME_US/2);
current_time = get_time();
if ((current_time.val - prev_watchdog_time.val) <
(CONFIG_WATCHDOG_PERIOD_MS * 1000 / 2))
continue;
watchdog_reload();
prev_watchdog_time.val = current_time.val;
}
uart_putc(c++);
if (seq_number && (++seq_counter == seq_number))
break;
if (wrap_value && (++wrap_counter == wrap_value)) {
c = '0';
wrap_counter = 0;
continue;
}
if (c == ('z' + 1))
c = '0';
else if (c == ('Z' + 1))
c = 'a';
else if (c == ('9' + 1))
c = 'A';
}
uart_putc('\n');
return 0;
}
DECLARE_SAFE_CONSOLE_COMMAND(chargen, command_chargen,
"[seq_length [num_chars]]",
"Generate a constant stream of characters on the "
"UART console,\nrepeating every 'seq_length' "
"characters, up to 'num_chars' total."
);
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