Check if active video mode is changed after OpROM starts, if active video mode is...

[mirror_edk2.git] / IntelFrameworkModulePkg / Csm / LegacyBiosDxe / LegacyPci.c

diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
index 45cdd037e668f664ae15073c2a779783dfc5049d..1d09bb879d41f3e51fa711c3091eb97ddc369f5f 100644 (file)
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
@@ -2380,7 +2380,7 @@ LegacyBiosInstallRom (
     //\r
     // Store current mode settings since PrepareToScanRom may change mode.\r
     //\r
-    VideoMode = *(UINT8 *) ((UINTN) 0x449);\r
+    VideoMode = *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE));\r
   }\r
   //\r
   // Notify the platform that we are about to scan the ROM\r
@@ -2520,9 +2520,14 @@ LegacyBiosInstallRom (
     //\r
     // Set mode settings since PrepareToScanRom may change mode\r
     //\r
-    Regs.H.AH = 0x00;\r
-    Regs.H.AL = VideoMode;\r
-    Private->LegacyBios.Int86 (&Private->LegacyBios, 0x10, &Regs);\r
+    if (VideoMode != *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE))) {\r
+      //\r
+      // The active video mode is changed, restore it to original mode.\r
+      //\r
+      Regs.H.AH = 0x00;\r
+      Regs.H.AL = VideoMode;\r
+      Private->LegacyBios.Int86 (&Private->LegacyBios, 0x10, &Regs);\r
+    }\r
   }\r
   //\r
   // Regs.X.AX from the adapter initializion is ignored since some adapters\r