Initial submission of the PCem-Experimental source code.

2016-06-26 00:34:39 +02:00
parent 09d7c4384f
commit fd2a5bc9f5
610 changed files with 184352 additions and 0 deletions
--- a/src/mcr.c
+++ b/src/mcr.c
@@ -0,0 +1,37 @@
+/*INTEL 82355 MCR emulation
+  This chip was used as part of many 386 chipsets
+  It controls memory addressing and shadowing*/
+#include "ibm.h"
+
+int nextreg6;
+uint8_t mcr22;
+int mcrlock,mcrfirst;
+void resetmcr()
+{
+        mcrlock=0;
+        mcrfirst=1;
+        shadowbios=0;
+}
+
+void writemcr(uint16_t addr, uint8_t val)
+{
+        printf("Write MCR %04X %02X %04X:%04X\n",addr,val,CS,cpu_state.pc);
+        switch (addr)
+        {
+                case 0x22:
+                if (val==6 && mcr22==6) nextreg6=1;
+                else                    nextreg6=0;
+//                if ((val&1) && (mcr22&1)) shadowbios=1;
+//                if (!(val&1) && !(mcr22&1)) shadowbios=0;
+//                if (!mcrfirst) shadowbios=val&1;
+//                mcrfirst=0;
+//                dumpregs();
+//                exit(-1);
+                break;
+                case 0x23:
+                if (nextreg6) shadowbios=!val;
+                break;
+        }
+        mcr22=val;
+}
+