Merge remote-tracking branch 'u-boot-imx/master'

[pandora-u-boot.git] / doc / README.autoboot

diff --git a/doc/README.autoboot b/doc/README.autoboot
index c971bb1..2042fe5 100644 (file)
--- a/doc/README.autoboot
+++ b/doc/README.autoboot
@@ -12,7 +12,7 @@
  *
  * 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
+ * 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
@@ -97,7 +97,7 @@ What they do
   CONFIG_AUTOBOOT_STOP_STR2
 
   "bootdelaykey"  environment variable
-  "bootstopkey"   environment variable
+  "bootstopkey"          environment variable
   "bootdelaykey2" environment variable
   "bootstopkey2"  environment variable
 
@@ -106,7 +106,7 @@ What they do
        stop or delay autoboot.
 
        Define CONFIG_AUTOBOOT_KEYED (no value required) to enable
-       this group of options.  CONFIG_AUTOBOOT_DELAY_STR,
+       this group of options.  CONFIG_AUTOBOOT_DELAY_STR,
        CONFIG_AUTOBOOT_STOP_STR or both should be specified (or
        specified by the corresponding environment variable),
        otherwise there is no way to stop autoboot.
@@ -114,22 +114,29 @@ 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.
-
-        If CONFIG_AUTOBOOT_DELAY_STR or "bootdelaykey" is specified
-        and this string is received from console input before
-        autoboot starts booting, U-Boot gives a command prompt. The
-        U-Boot prompt will time out if CONFIG_BOOT_RETRY_TIME is
-        used, otherwise it never times out.
-
-        If CONFIG_AUTOBOOT_STOP_STR or "bootstopkey" is specified and
-        this string is received from console input before autoboot
-        starts booting, U-Boot gives a command prompt. The U-Boot
-        prompt never times out, even if CONFIG_BOOT_RETRY_TIME is
-        used.
+
+       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
+       autoboot starts booting, U-Boot gives a command prompt. The
+       U-Boot prompt will time out if CONFIG_BOOT_RETRY_TIME is
+       used, otherwise it never times out.
+
+       If CONFIG_AUTOBOOT_STOP_STR or "bootstopkey" is specified and
+       this string is received from console input before autoboot
+       starts booting, U-Boot gives a command prompt. The U-Boot
+       prompt never times out, even if CONFIG_BOOT_RETRY_TIME is
+       used.
 
        The string recognition is not very sophisticated. If a
        partial match is detected, the first non-matching character
@@ -138,11 +145,11 @@ What they do
        character of a key string does not appear in the rest of the
        string.
 
-        Using the CONFIG_AUTOBOOT_DELAY_STR2 #define or the
-        "bootdelaykey2" environment variable and/or the
-        CONFIG_AUTOBOOT_STOP_STR2 #define or the "bootstopkey"
-        environment variable you can specify a second, alternate
-        string (which allows you to have two "password" strings).
+       Using the CONFIG_AUTOBOOT_DELAY_STR2 #define or the
+       "bootdelaykey2" environment variable and/or the
+       CONFIG_AUTOBOOT_STOP_STR2 #define or the "bootstopkey"
+       environment variable you can specify a second, alternate
+       string (which allows you to have two "password" strings).
 
   CONFIG_ZERO_BOOTDELAY_CHECK