Add LIM-EMS support

Makefile

@@ -1,5 +1,5 @@
 CC=cc
-CFLAGS=-O3 -flto -Wall -g -Werror=implicit-function-declaration -Werror=int-conversion
+CFLAGS=-O3 -flto -Wall -g -Werror=implicit-function-declaration -Werror=int-conversion -DEMS_SUPPORT
 LDLIBS=-lm
 INSTALL=install
 PREFIX=/usr
@@ -17,6 +17,7 @@ OBJS=\
  timer.o\
  utils.o\
  video.o\
+ ems.o\
 
 
 all: obj emu2
@@ -43,17 +44,19 @@ uninstall:
 
 # Generated with gcc -MM src/*.c
 obj/codepage.o: src/codepage.c src/codepage.h src/dbg.h src/env.h
-obj/cpu.o: src/cpu.c src/cpu.h src/dbg.h src/dis.h src/emu.h
+obj/cpu.o: src/cpu.c src/cpu.h src/dbg.h src/dis.h src/emu.h src/ems.h
 obj/dbg.o: src/dbg.c src/dbg.h src/env.h
-obj/dis.o: src/dis.c src/dis.h src/emu.h
+obj/dis.o: src/dis.c src/dis.h src/emu.h src/ems.h
 obj/dos.o: src/dos.c src/codepage.h src/dos.h src/dbg.h src/dosnames.h \
  src/emu.h src/env.h src/keyb.h src/loader.h src/timer.h src/utils.h \
- src/video.h
-obj/dosnames.o: src/dosnames.c src/dbg.h src/dosnames.h src/emu.h src/env.h
+ src/video.h src/ems.h
+obj/dosnames.o: src/dosnames.c src/dbg.h src/dosnames.h src/emu.h src/env.h \
+ src/ems.h
 obj/keyb.o: src/keyb.c src/keyb.h src/dbg.h src/emu.h src/codepage.h
 obj/loader.o: src/loader.c src/loader.h src/dbg.h src/emu.h
 obj/main.o: src/main.c src/dbg.h src/dos.h src/dosnames.h src/emu.h \
- src/keyb.h src/timer.h src/video.h
+ src/keyb.h src/timer.h src/video.h src/ems.h
 obj/timer.o: src/timer.c src/dbg.h src/timer.h src/emu.h
 obj/utils.o: src/utils.c src/utils.h src/dbg.h
 obj/video.o: src/video.c src/video.h src/dbg.h src/emu.h src/codepage.h
+obj/ems.o: src/ems.c src/emu.h src/ems.h

README.md

@@ -69,6 +69,9 @@ The available environment variables are:
                        "signed" comparison insructions (JLE instead of JBE).
                        This is needed at least for MASM versions 1.0 and 1.10.
 
+- `EMU2_EMSMEM`        Use LIM-EMS 4.0. Set this variable as available pages
+                       between 0 (no use) to 2048 (32MiB).
+                       The default is 0 (no use).
 
 Simple Example
 --------------

src/cpu.c

@@ -30,23 +30,22 @@ static uint16_t irq_mask; // IRQs pending
 
 static uint8_t GetMemAbsB(uint32_t addr)
 {
-    return memory[addr & 0xFFFFF];
+    return get8(addr);
 }
 
 static uint16_t GetMemAbsW(uint32_t addr)
 {
-    return memory[addr & 0xFFFFF] + 256 * memory[(addr + 1) & 0xFFFFF];
+    return get16(addr);
 }
 
 static void SetMemAbsB(uint32_t addr, uint8_t val)
 {
-    memory[0xFFFFF & addr] = val;
+    put8(addr, val);
 }
 
-static void SetMemAbsW(uint32_t addr, uint16_t x)
+static void SetMemAbsW(uint32_t addr, uint16_t val)
 {
-    memory[addr & 0xFFFFF] = x;
-    memory[(addr + 1) & 0xFFFFF] = x >> 8;
+    put16(addr, val);
 }
 
 static void SetMemB(uint16_t seg, uint16_t off, uint8_t val)
@@ -56,7 +55,7 @@ static void SetMemB(uint16_t seg, uint16_t off, uint8_t val)
 
 static uint8_t GetMemB(int seg, uint16_t off)
 {
-    return memory[0xFFFFF & (sregs[seg] * 16 + off)];
+    return GetMemAbsB(sregs[seg] * 16 + off);
 }
 
 static void SetMemW(uint16_t seg, uint16_t off, uint16_t val)
@@ -2636,6 +2635,11 @@ int cpuGetAddrES(uint16_t offset)
     return 0xFFFFF & (sregs[ES] * 16 + offset);
 }
 
+int cpuGetAddrSS(uint16_t offset)
+{
+    return 0xFFFFF & (sregs[ES] * 16 + offset);
+}
+
 uint16_t cpuGetStack(uint16_t disp)
 {
     return GetMemW(SS, wregs[SP] + disp);

src/dos.c

@@ -9,6 +9,7 @@
 #include "timer.h"
 #include "utils.h"
 #include "video.h"
+#include "ems.h"
 
 #include <errno.h>
 #include <fcntl.h>
@@ -369,6 +370,15 @@ static int dos_rw_record_fcb(int addr, int write, int update, int seq)
         pos = rsize * (0xFFFFFF & get32(0x21 + fcb));
 
     uint8_t *buf = getptr(addr, rsize);
+#ifdef EMS_SUPPORT
+    int buf_allocated = 0;
+    if (in_ems_pageframe2(addr, rsize)) {
+	buf_allocated = 1;
+	buf = malloc(rsize);
+	if (buf && write)
+	    ems_getmem(buf, addr, rsize);
+    }
+#endif
     if(!buf || !rsize)
     {
         debug(debug_dos, "\tbuffer pointer invalid\n");
@@ -392,16 +402,21 @@ static int dos_rw_record_fcb(int addr, int write, int update, int seq)
     if(write && (pos + n > get32(fcb + 0x10)))
         put32(fcb + 0x10, pos + n);
 
+    for(unsigned i = n; i < rsize; i++)
+	buf[i] = 0;
+#ifdef EMS_SUPPORT
+    if (buf_allocated) {
+	if (!write)
+	    ems_putmem(addr, buf, rsize);
+	free(buf);
+    }
+#endif
     if(n == rsize)
         return 0; // read/write full record
     else if(!n || write)
         return 1; // EOF on read, disk full on write
     else
-    {
-        for(unsigned i = n; i < rsize; i++)
-            buf[i] = 0;
         return 3; // read partial record
-    }
 }
 
 // Converts Unix time_t to DOS time/date
@@ -1417,7 +1432,16 @@ void int21()
             cpuSetAX(6); // invalid handle
             break;
         }
-        uint8_t *buf = getptr(cpuGetAddrDS(cpuGetDX()), cpuGetCX());
+	int len = cpuGetCX();
+	uint32_t addr = cpuGetAddrDS(cpuGetDX());
+	uint8_t *buf = getptr(addr, len);
+#ifdef EMS_SUPPORT
+	int buf_allocated = 0;
+	if (in_ems_pageframe2(addr, len)) {
+	    buf_allocated = 1;
+	    buf = malloc(len);
+	}
+#endif
         if(!buf)
         {
             debug(debug_dos, "\tbuffer pointer invalid\n");
@@ -1429,14 +1453,20 @@ void int21()
         if(devinfo[cpuGetBX()] == 0x80D3)
         {
             suspend_keyboard();
-            cpuSetAX(line_input(f, buf, cpuGetCX()));
+            cpuSetAX(line_input(f, buf, len));
         }
         else
         {
-            unsigned n = fread(buf, 1, cpuGetCX(), f);
+            unsigned n = fread(buf, 1, len, f);
             cpuSetAX(n);
         }
         cpuClrFlag(cpuFlag_CF);
+#ifdef EMS_SUPPORT
+	if (buf_allocated) {
+	    ems_putmem(addr, buf, len);
+	    free(buf);
+	}
+#endif
         break;
     }
     case 0x40: // WRITE
@@ -1449,7 +1479,18 @@ void int21()
             return;
         }
         unsigned len = cpuGetCX();
-        uint8_t *buf = getptr(cpuGetAddrDS(cpuGetDX()), len);
+	uint32_t addr = cpuGetAddrDS(cpuGetDX());
+	uint8_t *buf = getptr(addr, len);
+#ifdef EMS_SUPPORT
+	int buf_allocated = 0;
+	if (in_ems_pageframe2(addr, len)) {
+	    buf_allocated = 1;
+	    buf = malloc(len);
+	    if (buf) {
+		ems_getmem(buf, addr, len);
+	    }
+	}
+#endif
         if(!buf)
         {
             debug(debug_dos, "\tbuffer pointer invalid\n");
@@ -1469,6 +1510,10 @@ void int21()
             cpuSetAX(n);
         }
         cpuClrFlag(cpuFlag_CF);
+#ifdef EMS_SUPPORT
+	if (buf_allocated)
+	    free(buf);
+#endif
         break;
     }
     case 0x41: // UNLINK
@@ -2113,6 +2158,21 @@ void init_dos(int argc, char **argv)
     // Patch an INT 21 at address 0x000C0, this is for the CP/M emulation code
     memory[0x000C0] = 0xCD;
     memory[0x000C1] = 0x21;
+
+#ifdef EMS_SUPPORT
+    const char *emsmem = getenv(ENV_EMSMEM);
+    int ems_pages = 0;
+    if (emsmem != NULL) {
+	char *ep;
+	ems_pages = strtol(emsmem, &ep, 0);
+	if (*ep  || ems_pages < 0 || ems_pages > 2048)
+	    print_error("%s must be set between 0 to 2048\n", ENV_EMSMEM);
+    }
+    if (ems_pages != 0) {
+	debug(debug_dos, "set EMS pages = %d\n", ems_pages);
+	init_ems(ems_pages);
+    }
+#endif
 
     // Init memory handling - available start address at 0x800,
     // ending address at 0xA0000.

src/dosnames.c

@@ -575,6 +575,11 @@ char *dos_unix_path(int addr, int force, const char *append)
         return strdup("/dev/null");
     if(*path && (!strcasecmp(path, "CON") || !strcasecmp(path + 1, ":CON")))
         return strdup("/dev/tty");
+#ifdef EMS_SUPPORT
+    if(use_ems && *path && (!strcasecmp(path, "EMMXXXX0") ||
+		 !strcasecmp(path + 1, ":EMMXXXX0")))
+        return strdup("/dev/null");
+#endif
     // Try to convert
     char *result = dos_unix_path_base(path, force);
     // Be done if the path is found, or no append.