new .bochsrc memory option

bochs/.bochsrc

@@ -145,17 +145,23 @@ romimage: file=$BXSHARE/BIOS-bochs-latest
 cpu: count=1, ips=50000000, reset_on_triple_fault=1, cpuid_limit_winnt=0, msrs="msrs.def"
 
 #=======================================================================
-# MEGS
+# MEMORY
-# Set the number of Megabytes of physical memory you want to emulate. 
+# Set the amount of physical memory you want to emulate.
-# The default is 32MB, most OS's won't need more than that.
+#
-# The maximum amount of memory supported is 2048Mb.
+# GUEST:
+# Set amount of guest physical memory to emulate. The default is 32MB,
+# the maximum amount limited only by physical address space limitations.
+#
+# HOST:
+# Set amount of host memory you want to allocate for guest RAM emulation.
+# It is possible to allocate less memory than you want to emulate in guest
+# system. This will fake guest to see the non-existing memory. Once guest
+# system touches new memory block it will be dynamically taken from the
+# memory pool. You will be warned (by FATAL PANIC) in case guest already
+# used all allocated host memory and wants more.
+#
 #=======================================================================
-#megs: 256
+memory: guest=512, host=256
-#megs: 128
-#megs: 64
-megs: 32
-#megs: 16
-#megs: 8
 
 #=======================================================================
 # OPTROMIMAGE[1-4]:
@@ -867,3 +873,17 @@ i440fxsupport: enabled=1
 # romimage: file=:bios:BIOS-bochs-latest, address=0xf0000
 # floppya: 1_44=[fd:], status=inserted
 #=======================================================================
+
+#=======================================================================
+# MEGS
+# Set the number of Megabytes of physical memory you want to emulate. 
+# The default is 32MB, most OS's won't need more than that.
+# The maximum amount of memory supported is 2048Mb.
+# The 'MEGS' option is deprecated. Use 'MEMORY' option instead.
+#=======================================================================
+#megs: 256
+#megs: 128
+#megs: 64
+megs: 32
+#megs: 16
+#megs: 8

bochs/CHANGES

@@ -4,7 +4,11 @@ Changes for next bugfix+ release (coming soon):
   - VMX: Implemented TPR shadow VMEXIT
   - Bugfixes for CPU emulation correctness (mostly for VMX support).
   - Updates for Bochs internal debugger.
+
+- Memory
   - Bugfixes for > 32-bit physical address space.
+  - Allow to emulate more physical memory than host actually could or would
+    like to allocate. For more details look for new .bochsrc 'memory' option.
 
 - Cleanup configure options
   - All paging related options now will be automatically determined according

bochs/config.cc

@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////
-// $Id: config.cc,v 1.185 2009-10-12 20:53:00 sshwarts Exp $
+// $Id: config.cc,v 1.186 2009-10-17 17:38:58 sshwarts Exp $
 /////////////////////////////////////////////////////////////////////////
 //
 //  Copyright (C) 2002  MandrakeSoft S.A.
@@ -397,6 +397,15 @@ void bx_init_options()
   ramsize->set_ask_format("Enter memory size (MB): [%d] ");
   ramsize->set_options(ramsize->USE_SPIN_CONTROL);
 
+  bx_param_num_c *host_ramsize = new bx_param_num_c(ram,
+      "host_size",
+      "Host allocated memory size (megabytes)",
+      "Amount of host allocated memory in megabytes",
+      1, 4096,
+      BX_DEFAULT_MEM_MEGS);
+  host_ramsize->set_ask_format("Enter memory size (MB): [%d] ");
+  host_ramsize->set_options(ramsize->USE_SPIN_CONTROL);
+
   path = new bx_param_filename_c(rom,
       "path",
       "ROM BIOS image",
@@ -2532,6 +2541,20 @@ static int parse_line_formatted(const char *context, int num_params, char *param
       PARSE_ERR(("%s: megs directive: wrong # args.", context));
     }
     SIM->get_param_num(BXPN_MEM_SIZE)->set(atol(params[1]));
+    SIM->get_param_num(BXPN_HOST_MEM_SIZE)->set(atol(params[1]));
+  } else if (!strcmp(params[0], "memory")) {
+    if (num_params < 3) {
+      PARSE_ERR(("%s: memory directive malformed.", context));
+    }
+    for (i=1; i<num_params; i++) {
+      if (!strncmp(params[i], "host=", 5)) {
+        SIM->get_param_num(BXPN_HOST_MEM_SIZE)->set(atol(&params[i][5]));
+      } else if (!strncmp(params[i], "guest=", 6)) {
+        SIM->get_param_num(BXPN_MEM_SIZE)->set(atol(&params[i][6]));
+      } else {
+        PARSE_ERR(("%s: memory directive malformed.", context));
+      }
+    }
   } else if (!strcmp(params[0], "romimage")) {
     if ((num_params < 2) || (num_params > 3)) {
       PARSE_ERR(("%s: romimage directive: wrong # args.", context));
@@ -3558,7 +3581,8 @@ int bx_write_configuration(const char *rc, int overwrite)
     fprintf(fp, ", options=\"%s\"\n", strptr);
   else
     fprintf(fp, "\n");
-  fprintf(fp, "megs: %d\n", SIM->get_param_num(BXPN_MEM_SIZE)->get());
+  fprintf(fp, "memory: host=%d, guest=%d\n", SIM->get_param_num(BXPN_HOST_MEM_SIZE)->get(),
+    SIM->get_param_num(BXPN_MEM_SIZE)->get());
   strptr = SIM->get_param_string(BXPN_ROM_PATH)->getptr();
   if (strlen(strptr) > 0) {
     fprintf(fp, "romimage: file=\"%s\"", strptr);

bochs/gui/siminterface.h

@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////
-// $Id: siminterface.h,v 1.243 2009-10-16 18:29:45 sshwarts Exp $
+// $Id: siminterface.h,v 1.244 2009-10-17 17:38:58 sshwarts Exp $
 /////////////////////////////////////////////////////////////////////////
 //
 //  Copyright (C) 2009  The Bochs Project
@@ -155,6 +155,7 @@ typedef enum {
 #define BXPN_VENDOR_STRING               "cpu.vendor_string"
 #define BXPN_BRAND_STRING                "cpu.brand_string"
 #define BXPN_MEM_SIZE                    "memory.standard.ram.size"
+#define BXPN_HOST_MEM_SIZE               "memory.standard.ram.host_size"
 #define BXPN_ROM_PATH                    "memory.standard.rom.path"
 #define BXPN_ROM_ADDRESS                 "memory.standard.rom.addr"
 #define BXPN_VGA_ROM_PATH                "memory.standard.vgarom.path"

bochs/main.cc

@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////
-// $Id: main.cc,v 1.406 2009-10-16 17:10:36 sshwarts Exp $
+// $Id: main.cc,v 1.407 2009-10-17 17:38:58 sshwarts Exp $
 /////////////////////////////////////////////////////////////////////////
 //
 //  Copyright (C) 2002  MandrakeSoft S.A.
@@ -1053,9 +1053,12 @@ void bx_init_hardware()
 
   // set up memory and CPU objects
   bx_param_num_c *bxp_memsize = SIM->get_param_num(BXPN_MEM_SIZE);
-  Bit32u memSize = bxp_memsize->get() * 1024*1024;
+  Bit64u memSize = bxp_memsize->get() * 1024*1024;
 
-  BX_MEM(0)->init_memory(memSize, memSize);
+  bx_param_num_c *bxp_host_memsize = SIM->get_param_num(BXPN_HOST_MEM_SIZE);
+  Bit64u hostMemSize = bxp_host_memsize->get() * 1024*1024;
+
+  BX_MEM(0)->init_memory(memSize, hostMemSize);
 
   // First load the BIOS and VGABIOS
   BX_MEM(0)->load_ROM(SIM->get_param_string(BXPN_ROM_PATH)->getptr(),