sandbox: Add a simple sound driver

[karo-tx-uboot.git] / doc / README.autoboot

diff --git a/doc/README.autoboot b/doc/README.autoboot
index e4c41867351a2233bc623c753adc00eaf3919dd1..14e3660dd8d7634e058d280bed1e457de8838066 100644 (file)
--- a/doc/README.autoboot
+++ b/doc/README.autoboot
@@ -2,23 +2,7 @@
  * (C) Copyright 2001
  * Dave Ellis, SIXNET, dge@sixnetio.com
  *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.         See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * SPDX-License-Identifier:    GPL-2.0+
  */
 
 Using autoboot configuration options
@@ -90,6 +74,7 @@ What they do
        "bootretry" is >= 0.
 
   CONFIG_AUTOBOOT_KEYED
+  CONFIG_AUTOBOOT_KEYED_CTRLC
   CONFIG_AUTOBOOT_PROMPT
   CONFIG_AUTOBOOT_DELAY_STR
   CONFIG_AUTOBOOT_STOP_STR
@@ -114,10 +99,17 @@ What they do
        CONFIG_AUTOBOOT_PROMPT is displayed before the boot delay
        selected by CONFIG_BOOTDELAY starts. If it is not defined
        there is no output indicating that autoboot is in progress.
-       If "%d" is included, it is replaced by the number of seconds
-       remaining before autoboot will start, but it does not count
-       down the seconds. "autoboot in %d seconds\n" is a reasonable
-       prompt.
+
+       Note that CONFIG_AUTOBOOT_PROMPT is used as the (only)
+       argument to a printf() call, so it may contain '%' format
+       specifications, provided that it also includes, sepearated by
+       commas exactly like in a printf statement, the required
+       arguments. It is the responsibility of the user to select only
+       such arguments that are valid in the given context. A
+       reasonable prompt could be defined as
+
+               #define CONFIG_AUTOBOOT_PROMPT \
+                       "autoboot in %d seconds\n",bootdelay
 
        If CONFIG_AUTOBOOT_DELAY_STR or "bootdelaykey" is specified
        and this string is received from console input before
@@ -144,6 +136,13 @@ What they do
        environment variable you can specify a second, alternate
        string (which allows you to have two "password" strings).
 
+       The CONFIG_AUTOBOOT_KEYED_CTRLC #define allows for the boot
+       sequence to be interrupted by ctrl-c, in addition to the
+       "bootdelaykey" and "bootstopkey". Setting this variable
+       provides an escape sequence from the limited "password"
+       strings.
+
+
   CONFIG_ZERO_BOOTDELAY_CHECK
 
        If this option is defined, you can stop the autoboot process