[tkreuzer] 70407: [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 a...

Author: tkreuzer
Date: Mon Dec 21 19:36:10 2015
New Revision: 70407

URL: http://svn.reactos.org/svn/reactos?rev=70407&view=rev
Log:
[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.

Modified:
    trunk/reactos/boot/freeldr/freeldr/arch/amd64/pnpbios.S

Modified: trunk/reactos/boot/freeldr/freeldr/arch/amd64/pnpbios.S
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/arch/…
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/arch/amd64/pnpbios.S	[iso-8859-1] (original)
+++ trunk/reactos/boot/freeldr/freeldr/arch/amd64/pnpbios.S	[iso-8859-1] Mon Dec 21
19:36:10 2015
@@ -104,9 +104,17 @@
 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]
@@ -140,9 +148,15 @@
     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]