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a7out: changes for shell

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handle "ptr" format executable files
tty read always returns only one character
add shell-compatible "smes" behavior
This commit is contained in:
Phil Budne 2016-03-07 17:27:31 -05:00
parent e18a74300e
commit 38ff8aec09
1 changed files with 51 additions and 23 deletions
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tools/a7out
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@ -81,6 +81,18 @@ sub load_code {
# Open up the PDP-7 executable file
open( my $IN, "<", $filename ) || die("Unable to open $filename: $!\n");
my $c = getc($IN);
seek $IN, 0, 0;
if ((ord($c) & 0300) == 0200) { # handle "binary paper tape" format
my $addr = 010000; # user programs loaded at 4K mark
while ($addr <= 017777) {
my $result = read_word($IN);
last if ($result == -1);
$Mem[$addr++] = $result;
}
close($IN);
return;
}
while (<$IN>) {
chomp;
@ -98,6 +110,18 @@ sub load_code {
close($IN);
}
### read a word from a file in paper tape binary format
### return -1 on EOF
sub read_word {
my $F = shift;
# Convert three bytes into one 18-bit word
return -1 if ( read( $F, my $three, 3 ) != 3 ); # Not enough bytes read
my ( $b1, $b2, $b3 ) = unpack( "CCC", $three );
return ((($b1 & 077) << 12 ) |
(($b2 & 077) << 6 ) |
($b3 & 077));
}
### Copy the arguments into the PDP-7 memory space, and build
### an array of pointers to these arguments. Build a pointer
### at MAXADDR that points at the array.
@ -711,16 +735,19 @@ sub sys_fork {
return;
}
# Smes system call. Because we fake rmes with wait(),
# there is no need for sms. When the child does
# sys exit, that's going to wake wait() up and do the
# rmes anyway.
# shell depends on smes hanging while child process exists
" https://www.bell-labs.com/usr/dmr/www/hist.html
" The message facility was used as follows: the parent shell, after
" creating a process to execute a command, sent a message to the new
" process by smes; when the command terminated (assuming it did not
" try to read any messages) the shell's blocked smes call returned an
" error indication that the target process did not exist. Thus the
" shell's smes became, in effect, the equivalent of wait.
sub sys_smes {
# For now, do nothing
dprintf("smes system call\n");
waitpid($AC,0);
dprintf("smes returning error\n");
$AC = -1;
$PC += 1;
return;
}
# Rmes system call. We simply call wait and
@ -927,34 +954,35 @@ sub sys_read {
# Read each word in
my $FH = $FD[$fd];
$count = 0;
my $tty = -t $FH;
if (-t $FH) { # TTY?
my $char = getc($FH); # use Term::ReadKey for 'cbreak' mode??
if (defined($char)) {
$Mem[$start] = ord($char) << 9; # only ever returns one char
$AC = 1;
}
else {
$AC = 0; # EOF
}
return;
}
foreach my $addr ( $start .. $end ) {
if ( $ISBINARY[$fd] ) {
# Convert three bytes into one 18-bit word
my $result = read( $FH, my $three, 3 );
last if ( $result != 3 ); # Not enough bytes read
my ( $b1, $b2, $b3 ) = unpack( "CCC", $three );
$Mem[$addr] = ((($b1 & 077) << 12 ) |
(($b2 & 077) << 6 ) |
($b3 & 077));
my $result = read_word($FH);
last if ($result == -1);
$Mem[$addr] = $result;
$count++;
}
else {
# Convert two ASCII characters into one 18-bit word
my $c1 = getc($FH);
my $c2;
last if ( !defined($c1) ); # No character, leave the loop
my $word = ord($c1) << 9;
if ( !$tty || $c1 ne "\n") {
$c2 = getc($FH);
if (defined($c2)) {
$word |= ord($c2);
}
}
my $c2 = getc($FH);
$word |= ord($c2) if (defined($c2));
$Mem[$addr] = $word;
$count++;
last if ($tty && (($c1 && ($c1 eq "\n")) || ($c2 &&($c2 eq "\n"))));
} # ascii
}