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tools/as7: added syscalls chmod and chown, added auto-increment

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locations, fixed a bug in character input, added several EAE
instructions. We now have cp.s, chmod.s and chown.s working.
This commit is contained in:
Warren Toomey
2016-03-02 17:55:33 +10:00
parent 5bda1307c9
commit a3d6090fe7
6 changed files with 349 additions and 260 deletions
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tools/a7out
+134 -70
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@@ -16,7 +16,7 @@ my @Mem; # 8K 18-bit words of main memory
my @FD; # Array of open filehandles
# Registers
my $PC = 0; # Program counter
my $PC = 020; # Program counter
my $AC = 0; # Accumulator
my $LINK = 0; # Link register, either 0 or LINKMASK
my $MQ = 0; # MQ register
@@ -172,6 +172,14 @@ sub simulate {
oct("074") => \&opr,
);
# List of opcodes that DON'T auto-increment
# locations 10-17 when we have the indirect bit
my %NoIncr = (
oct("000") => 1, # cal
oct("064") => 1, # eae
oct("074") => 1 # opr
);
# Loop indefinitely
while (1) {
@@ -181,6 +189,14 @@ sub simulate {
my $indirect = ( $instruction >> 13 ) & 1;
my $addr = $instruction & MAXADDR;
# Auto-increment locations 010 to 017 if $indirect
# and this is an instruction that does increment
if ($indirect && ($addr >= 010) && ($addr <= 017) &&
!defined($NoIncr{$opcode})) {
$Mem[$addr]++;
$Mem[$addr] &= MAXINT;
}
# Work out what any indirect address would be
my $indaddr = ($indirect) ? $Mem[$addr] & MAXADDR : $addr;
@@ -212,7 +228,12 @@ sub simulate {
sub dump_memory {
my ( $start, $end, $yeszero ) = @_;
foreach my $i ( $start .. $end ) {
printf( STDERR "%06o: %06o\n", $i, $Mem[$i] )
# Convert the word into possibly two ASCII characters
my $c1= ($Mem[$i] >> 9) & 0777;
$c1= ($c1 < 0200) ? chr($c1) : " ";
my $c2= $Mem[$i] & 0777;
$c2= ($c2 < 0200) ? chr($c2) : " ";
printf( STDERR "%06o: %06o %s%s\n", $i, $Mem[$i], $c1, $c2)
if ( $yeszero || $Mem[$i] != 0 );
}
}
@@ -239,8 +260,8 @@ sub tad {
dprintf( "tad AC (value %06o) with addr %06o (%06o)\n",
$AC, $indaddr, $Mem[$indaddr] );
$AC = $AC + $Mem[$indaddr];
$LINK = ($LINK ^ $AC) & LINKMASK;
$AC = $AC & MAXINT;
$LINK = $AC & LINKMASK;
$PC++;
}
@@ -445,6 +466,60 @@ sub opr {
return;
}
# Extended arithmetic element instructions
sub eae {
my ( $instruction, $addr, $indaddr ) = @_;
my $step = $instruction & EAESTEP;
my $maskedinstr= $instruction & EAEIMASK;
if ( $maskedinstr == 0660500 ) { # lrss: long right shift, signed
# We ignore the MQ as it's not
# used by any user-mode programs
dprintf( "lrss %06o AC step %d\n", $AC, $step );
# Save the AC's sign into LINK
my $newlink = ( $AC << 1 ) & LINKMASK;
$AC = ( ( $LINK | $AC ) >> $step ) & MAXINT;
$LINK = $newlink;
$PC++;
return;
}
if ( $maskedinstr == 0660700 ) { # alss: long left shift, signed
# We don't fill the lsb with LINK yet
dprintf( "alss AC %06o step %d\n", $AC, $step );
$AC = ( $AC << $step ) & MAXINT;
$PC++;
return;
}
if ( $maskedinstr == 0640700 ) { # als: long left shift
dprintf( "alss AC %06o step %d\n", $AC, $step );
$AC = ( $AC << $step ) & MAXINT;
$PC++;
return;
}
if ( $instruction == 0652000 ) { # lmq: load MC from AC
dprintf( "lmq AC %06o into MQ\n", $AC);
$MQ= $AC;
$PC++;
return;
}
if ( $instruction == 0641002 ) { # lacq: load AC from MQ
dprintf( "lacq MQ %06o into AC\n", $MQ);
$AC= $MQ;
$PC++;
return;
}
if ( $instruction == 0640002 ) { # lacq: OR AC with MQ
dprintf( "omq MQ %06o and AC %06o\n", $MQ, $AC);
$AC |= $MQ;
$PC++;
return;
}
printf( STDERR "PC %06o: Unknown eae instruction %06o\n",
$PC, $instruction );
exit(1);
}
# cal: used for system calls
sub cal {
my ( $instruction, $addr, $indaddr ) = @_;
@@ -457,6 +532,8 @@ sub cal {
6 => \&sys_creat,
9 => \&sys_close,
14 => \&sys_exit,
18 => \&sys_chmod,
19 => \&sys_chown,
);
# Simulate the syscall. Each syscall updates the $PC
@@ -468,36 +545,6 @@ sub cal {
}
}
# Extended arithmetic element instructions
sub eae {
my ( $instruction, $addr, $indaddr ) = @_;
my $step = $instruction & EAESTEP;
$instruction &= EAEIMASK;
if ( $instruction == 0660500 ) { # lrss: long right shift, signed
# We ignore the MQ as it's not
# used by any user-mode programs
dprintf( "lrss %06o AC step %d\n", $AC, $step );
# Save the AC's sign into LINK
my $newlink = ( $AC << 1 ) & LINKMASK;
$AC = ( ( $LINK | $AC ) >> $step ) & MAXINT;
$LINK = $newlink;
$PC++;
return;
}
if ( $instruction == 0660700 ) { # alss: long left shift, signed
# We don't fill the lsb with LINK yet
dprintf( "alss %06o AC step %d\n", $AC, $step );
$AC = ( $AC << $step ) & MAXINT;
$PC++;
return;
}
printf( STDERR "PC %06o: Unknown eae instruction %06o\n",
$PC, $instruction );
exit(1);
}
# Exit system call
sub sys_exit {
dprintf("exit system call\n");
@@ -558,9 +605,8 @@ sub sys_open {
# AC is the opened fd on success, or -1 on error
# Get the start address of the string
my $start = $Mem[ $PC + 1 ];
# Convert this to a sensible ASCII filename
my $start = $Mem[ $PC + 1 ];
my $filename = mem2arg($start);
# Choose to open read-only or write-only
@@ -576,7 +622,7 @@ sub sys_open {
# Creat system call
sub sys_creat {
# Open seems to have 1 arguments: PC+1 is a pointer to the filename.
# Creat seems to have 1 argument: PC+1 is a pointer to the filename.
# Some programs seem to have a second argument always set to 0.
# AC is the opened fd on success, or -1 on error
@@ -629,7 +675,8 @@ sub sys_read {
my $c1 = getc($FH);
last if ( !defined($c1) ); # No character, leave the loop
my $c2 = getc($FH) || ""; # No character, make it a NUL
my $c2 = getc($FH); # No character, make it a NUL
$c2= "" if (!defined($c2));
$Mem[$addr] =
( ord($c1) << 9 ) | ord($c2); # Pack both into one word
$count++;
@@ -642,7 +689,6 @@ sub sys_read {
# Write system call
sub sys_write {
# Write seems to have arguments: AC is the file descriptor, PC+1 is
# the pointer to the buffer and PC+2 is the number of words to write
@@ -677,6 +723,56 @@ sub sys_write {
return;
}
# Chmod system call
sub sys_chmod {
# Chmod gets the permission bits in AC and a pointer
# to the file's name in PC+1. s2.s has these instruction for chmod:
# lac u.ac; and o17 so only the lowest 4
# bits are the permission bits that can be set.
# I'm going to guess these (from v1 chmod manual):
# 01 write for non-owner
# 02 read for non-owner
# 04 write for owner
# 10 read for owner
my $mode;
$mode|= 0002 if ($AC & 01);
$mode|= 0004 if ($AC & 02);
$mode|= 0220 if ($AC & 04);
$mode|= 0440 if ($AC & 010);
my $start = $Mem[ $PC + 1 ];
my $filename = mem2arg($start);
dprintf( "chmod %06o file %s\n", $mode, $filename);
# Do the chmod on the file
my $result= chmod($mode, $filename);
# Set AC to -1 if no files were changed, else 0
$AC= ($result == 0) ? MAXINT : 0;
$PC += 2;
return;
}
# Chown system call
sub sys_chown {
# Chown gets the numeric user-id in AC and a pointer
# to the file's name in PC+1.
# Get the start address of the string
# Convert this to a sensible ASCII filename
my $start = $Mem[ $PC + 1 ];
my $filename = mem2arg($start);
dprintf( "chown file %s to uid %06o\n", $filename, $AC);
# Do the chown, leave group-id untouched. Get number of files changed
my $result= chown($AC, -1, $filename);
# Set AC to -1 if no files were changed, else 0
$AC= ($result == 0) ? MAXINT : 0;
$PC += 2;
return;
}
# Convert an 18-bit word into two ASCII characters and return them.
# Don't return NUL characters
sub word2ascii {
@@ -709,38 +805,6 @@ sub mem2arg {
return ($result);
}
# Given the address of a word in memory, interpret that location
# and those following as a NUL-terminated ASCII string and return
# a copy of this string
# XXX: not sure if I still need this.
sub mem2string {
my $addr = shift;
my $result = "";
while (1) {
# Stop when the address leave the 8K word address space
return ($result) if ( $addr > MAXADDR );
# Stop when the value there is zero
my $word = $Mem[$addr];
return ($result) if ( $word == 0 );
# Get the top ASCII character, return if NUL
my $c1 = ( $word >> 9 ) & 0177;
return ($result) if ( $c1 == 0 );
$result .= chr($c1);
# Get the bottom ASCII character, return if NUL
my $c2 = $word & 0177;
return ($result) if ( $c2 == 0 );
$result .= chr($c2);
# Move up to the next address
$addr++;
}
}
# Print out debug messages
sub dprintf {
printf( STDERR @_ ) if ( ($debug) || ($singlestep) );