Ticket #5822: boot-memory.diff

src/system/boot/platform/bios_ia32/mmu.cpp

@@ -716 +716 @@
             }
         }
     } else {
-        // TODO: for now!
-        dprintf("No extended memory block - using 64 MB (fix me!)\n");
-        uint32 memSize = 64 * 1024 * 1024;
-
+        bios_regs regs;
+        
         // We dont have an extended map, assume memory is contiguously mapped
         // at 0x0, but leave out the BIOS range ((640k - 1 page) to 1 MB).
         gKernelArgs.physical_memory_range[0].start = 0;
         gKernelArgs.physical_memory_range[0].size = 0x9f000;
         gKernelArgs.physical_memory_range[1].start = 0x100000;
-        gKernelArgs.physical_memory_range[1].size = memSize - 0x100000;
-        gKernelArgs.num_physical_memory_ranges = 2;
+
+        regs.eax = 0xe801; // AX
+        call_bios(0x15, &regs);
+        if (regs.flags & CARRY_FLAG) {
+            regs.eax = 0x8800; // AH 88h
+            call_bios(0x15, &regs);
+            if (regs.flags & CARRY_FLAG) {
+                // TODO: for now!
+                dprintf("No memory size - using 64 MB (fix me!)\n");
+                uint32 memSize = 64 * 1024 * 1024;
+                gKernelArgs.physical_memory_range[1].size = memSize - 0x100000;
+            } else {
+                dprintf("Get Extended Memory Size succeeded.\n");
+                gKernelArgs.physical_memory_range[1].size = regs.eax * 1024;
+            }
+            gKernelArgs.num_physical_memory_ranges = 2;
+        } else {
+            dprintf("Get Memory Size for Large Configurations succeeded.\n");
+            gKernelArgs.physical_memory_range[1].size = regs.ecx * 1024;
+            gKernelArgs.physical_memory_range[2].start = 0x1000000;
+            gKernelArgs.physical_memory_range[2].size = regs.edx * 64 * 1024;
+            gKernelArgs.num_physical_memory_ranges = 3;
+        }
     }
 
     gKernelArgs.arch_args.page_hole = 0xffc00000;