[FREELDR/AMD64]

Save parameter registers (rcx, rdx) before calling CallRealMode. Patch by andy-123, applied to a secondary location by me.
CORE-10511 #resolve #comment Thanks. I added the same fix to PnpBiosGet below.

svn path=/trunk/; revision=70407

reactos/boot/freeldr/freeldr/arch/amd64/pnpbios.S

@@ -104,10 +104,18 @@ pnp_not_found:
 PUBLIC PnpBiosGetDeviceNodeCount
 PnpBiosGetDeviceNodeCount:
 
+    /* Save param-regs */
+    push rcx
+    push rdx
+
     /* Call the real mode function */
     mov bx, FNID_PnpBiosGetDeviceNodeCount
     call CallRealMode
 
+    /* Restore param-regs */
+    pop rdx
+    pop rcx
+
     xor eax, eax
     mov ax, [BSS_PnpNodeSize]
     mov [rcx], eax
@@ -140,10 +148,16 @@ PnpBiosGetDeviceNode:
     and eax, HEX(0f)
     mov word ptr [BSS_PnpBiosBufferOffset], ax
 
+    /* Save rcx */
+    push rcx
+
     /* Call the real mode function */
     mov bx, FNID_PnpBiosGetDeviceNode
     call CallRealMode
 
+    /* Restore rcx */
+    pop rcx
+
     /* update node number */
     mov al, byte ptr [BSS_PnpNodeNumber]
     mov [rcx], al