.EXB core image format.

Author: larsbrinkhoff

Makefile

@@ -3,7 +3,7 @@ CFLAGS = -g -W -Wall
 
 FILES =  sblk-file.o pdump-file.o dmp-file.o raw-file.o shr-file.o \
 	 mdl-file.o rim10-file.o fasl-file.o palx-file.o lda-file.o \
-	 cross-file.o hex-file.o atari-file.o iml-file.o
+	 cross-file.o hex-file.o atari-file.o iml-file.o exb-file.o
 
 WORDS =  aa-word.o bin-word.o cadr-word.o core-word.o data8-word.o \
 	 dta-word.o its-word.o oct-word.o pt-word.o sail-word.o tape-word.o \

check.sh

@@ -72,6 +72,7 @@ test_dis10 its.rp06       "-mks10_its"
 test_dis10 system.dmp     "-Fdmp -Woct -mka10sail -Sall"
 test_dis10 dired.dmp      "-6 -mka10sail -Wascii -Sddt"
 test_dis10 two.tapes      "-r -Wtape"
+test_dis10 boot.exb       "-Fexb -Wascii"
 
 test_itsarc arc.code
 test_ipak stink.-ipak-

dis.h

@@ -66,6 +66,7 @@ extern struct file_format *output_file_format;
 extern struct file_format atari_file_format;
 extern struct file_format cross_file_format;
 extern struct file_format dmp_file_format;
+extern struct file_format exb_file_format;
 extern struct file_format fasl_file_format;
 extern struct file_format hex_file_format;
 extern struct file_format iml_file_format;

exb-file.c

@@ -0,0 +1,231 @@
+/* Copyright (C) 2022 Lars Brinkhoff <lars@nocrew.org>
+
+    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, see <http://www.gnu.org/licenses/>.  */
+
+/* This file format will read in a paper tape with a hardware read-in
+   loader.  To do this, it will read in the loader and run it by
+   emulating a tiny subset of PDP-10 instructions.  The subset is enough to
+   support the ITS RIM10 and DEC RIM10B loaders. */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "dis.h"
+#include "memory.h"
+
+static int
+read_8 (FILE *f)
+{
+  static int i = 0;
+  static word_t word;
+
+  if (i == 0)
+    {
+      word = get_word (f);
+      if (word == -1)
+	return -1;
+      i = 4;
+    }
+
+  i--;
+  switch (i)
+    {
+    case 0: return (word >>  8) & 0377;
+    case 1: return (word >>  0) & 0377;
+    case 2: return (word >> 26) & 0377;
+    case 3: return (word >> 18) & 0377;
+    }
+
+  return -1;
+}
+
+static int
+read_16 (FILE *f)
+{
+  int x1, x2;
+  x1 = read_8 (f);
+  if (x1 == -1)
+    return 0;
+  x2 = read_8 (f);
+  if (x2 == -1)
+    x2 = 0;
+  return x1 | (x2 << 8);
+}
+
+static word_t
+read_32 (FILE *f)
+{
+  word_t x1, x2;
+  x1 = read_16 (f);
+  if (feof (f))
+    return 0;
+  x2 = read_16 (f);
+  if (feof (f))
+    x2 = 0;
+  return x1 | (x2 << 16);
+}
+
+static word_t
+read_36 (FILE *f)
+{
+  word_t x1, x2;
+  x1 = read_32 (f);
+  if (feof (f))
+    return 0;
+  x2 = read_8 (f);
+  if (feof (f))
+    x2 = 0;
+  return x1 | (x2 << 32);
+}
+
+static void
+read_exb (FILE *f, struct pdp10_memory *memory, int cpu_model)
+{
+  int i, address, length;
+  word_t *core;
+  word_t word;
+
+  (void)cpu_model;
+
+  fprintf (output_file, "EXB format\n");
+
+  for (;;)
+    {
+      length = read_16 (f);
+      address = read_32 (f);
+
+      if (feof (f) || length < 4)
+	{
+	  fprintf (stderr, "Unexpected end of file.\n");
+	  exit (1);
+	}
+
+      if (length == 4)
+	{
+	  fprintf (output_file, "Start address: %06o\n", address);
+	  start_instruction = JRST + address;
+	  return;
+	}
+
+      length -= 4;
+      length /= 5;
+
+      core = malloc (length * sizeof (word_t));
+      if (core == NULL)
+	{
+	  fprintf (stderr, "Out of memory.\n");
+	  exit (1);
+	}
+
+      for (i = 0; i < length; i++)
+	{
+	  word = read_36 (f);
+	  if (feof (f))
+	    {
+	      fprintf (stderr, "Unexpected end of file.\n");
+	      exit (1);
+	    }
+	  core[i] = word;
+	}
+
+      if (length & 1)
+	read_8 (f);
+
+      add_memory (memory, address, length, core);
+    }
+}
+
+static void
+write_8 (FILE *f, int data)
+{
+  static word_t word = 0;
+  static int i = 0;
+
+  data &= 0377;
+  switch (i)
+    {
+    case 0: word |= data << 18; break;
+    case 1: word |= data << 26; break;
+    case 2: word |= data <<  0; break;
+    case 3: word |= data <<  8; break;
+    }
+
+  i++;
+  if (i == 4)
+    {
+      write_word (f, word);
+      word = 0;
+      i = 0;
+    }
+}
+
+static void
+write_16 (FILE *f, int data)
+{
+  write_8 (f, data);
+  write_8 (f, data >> 8);
+}
+
+static void
+write_32 (FILE *f, int data)
+{
+  write_16 (f, data);
+  write_16 (f, data >> 16);
+}
+
+static void
+write_36 (FILE *f, word_t data)
+{
+  write_32 (f, data);
+  write_8 (f, data >> 32);
+}
+
+static void
+write_block (FILE *f, struct pdp10_memory *memory, int address, int length)
+{
+  int i;
+
+  write_16 (f, 5*length + 4);
+  write_32 (f, address);
+
+  for (i = address; i < address + length; i++)
+    write_36 (f, get_word_at (memory, i));
+
+  if (length & 1)
+    write_8 (f, 0);
+}
+
+static void
+write_exb (FILE *f, struct pdp10_memory *memory)
+{
+  int start, length;
+  int i;
+
+  for (i = 0; i < memory->areas; i++)
+    {
+      start = memory->area[i].start;
+      length = memory->area[i].end - start;
+      write_block (f, memory, start, length);
+    }
+
+  start = start_instruction & 0777777;
+  if (start)
+    write_block (f, memory, start, 0);
+}
+
+struct file_format exb_file_format = {
+  "exb",
+  read_exb,
+  write_exb
+};

file.c

@@ -26,6 +26,7 @@ static struct file_format *file_formats[] = {
   &atari_file_format,
   &cross_file_format,
   &dmp_file_format,
+  &exb_file_format,
   &fasl_file_format,
   &hex_file_format,
   &iml_file_format,