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Diffstat (limited to 'sys/boot/forth/delay.4th')
| -rw-r--r-- | sys/boot/forth/delay.4th | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/sys/boot/forth/delay.4th b/sys/boot/forth/delay.4th new file mode 100644 index 0000000..3068e65 --- /dev/null +++ b/sys/boot/forth/delay.4th @@ -0,0 +1,112 @@ +\ Copyright (c) 2008-2011 Devin Teske <devinteske@hotmail.com> +\ All rights reserved. +\ +\ Redistribution and use in source and binary forms, with or without +\ modification, are permitted provided that the following conditions +\ are met: +\ 1. Redistributions of source code must retain the above copyright +\ notice, this list of conditions and the following disclaimer. +\ 2. Redistributions in binary form must reproduce the above copyright +\ notice, this list of conditions and the following disclaimer in the +\ documentation and/or other materials provided with the distribution. +\ +\ THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +\ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +\ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +\ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +\ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +\ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +\ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +\ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +\ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +\ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +\ SUCH DAMAGE. +\ +\ $FreeBSD$ + +marker task-delay.4th + +2 constant delay_default \ Default delay (in seconds) +3 constant etx_key \ End-of-Text character produced by Ctrl+C +13 constant enter_key \ Carriage-Return character produce by ENTER +27 constant esc_key \ Escape character produced by ESC or Ctrl+[ + +variable delay_tstart \ state variable used for delay timing +variable delay_delay \ determined configurable delay duration +variable delay_cancelled \ state variable for user cancellation +variable delay_showdots \ whether continually print dots while waiting + +: delay_execute ( -- ) + + \ make sure that we have a command to execute + s" delay_command" getenv dup -1 = if + drop exit + then + + \ read custom time-duration (if set) + s" loader_delay" getenv dup -1 = if + drop \ no custom duration (remove dup'd bunk -1) + delay_default \ use default setting (replacing bunk -1) + else + \ make sure custom duration is a number + ?number 0= if + delay_default \ use default if otherwise + then + then + + \ initialize state variables + delay_delay ! \ stored value is on the stack from above + seconds delay_tstart ! \ store the time we started + 0 delay_cancelled ! \ boolean flag indicating user-cancelled event + + false delay_showdots ! \ reset to zero and read from environment + s" delay_showdots" getenv dup -1 <> if + 2drop \ don't need the value, just existance + true delay_showdots ! + else + drop + then + + \ Loop until we have exceeded the desired time duration + begin + 25 ms \ sleep for 25 milliseconds (40 iterations/sec) + + \ throw some dots up on the screen if desired + delay_showdots @ if + ." ." \ dots visually aid in the perception of time + then + + \ was a key depressed? + key? if + key \ obtain ASCII value for keystroke + dup enter_key = if + -1 delay_delay ! \ break loop + then + dup etx_key = swap esc_key = OR if + -1 delay_delay ! \ break loop + -1 delay_cancelled ! \ set cancelled flag + then + then + + \ if the time duration is set to zero, loop forever + \ waiting for either ENTER or Ctrl-C/Escape to be pressed + delay_delay @ 0> if + \ calculate elapsed time + seconds delay_tstart @ - delay_delay @ > + else + -1 \ break loop + then + until + + \ if we were throwing up dots, throw up a line-break + delay_showdots @ if + cr + then + + \ did the user press either Ctrl-C or Escape? + delay_cancelled @ if + 2drop \ we don't need the command string anymore + else + evaluate \ evaluate/execute the command string + then +; |
