OcBootManagementLib: Workaround setting Boot0000 causing ASUS FW issues

acidanthera · Dec 3, 2020 · cc6aa31 · cc6aa31
1 parent 1f2982b
commit cc6aa31
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/Library/OcBootManagementLib/DefaultEntryChoice.c b/Library/OcBootManagementLib/DefaultEntryChoice.c
@@ -1053,7 +1053,12 @@ InternalRegisterBootstrapBootOption (
       // Find the lowest unused Boot#### index. In the absolutely unrealistic case
       // that all entries are occupied, always overwrite BootFFFF.
       //
-      for (BootOptionIndex = 0; BootOptionIndex < 0xFFFF; ++BootOptionIndex) {
+      // Boot0000 is reserved on ASUS boards and is treated like a deleted entry.
+      // Setting Boot0000 will essentially cause entries to duplicate and eventual
+      // BIOS brick as ASUS boards simply zero removed boot entries instead of
+      // shrinking BootOrder size. Reproduced on ASUS ROG STRIX Z370-F GAMING.
+      //
+      for (BootOptionIndex = 1; BootOptionIndex < 0xFFFF; ++BootOptionIndex) {
         for (OrderIndex = 0; OrderIndex < BootOrderSize / sizeof (*BootOrder); ++OrderIndex) {
           if (BootOrder[OrderIndex + 1] == BootOptionIndex) {
             break;

diff --git a/Library/OcBootManagementLib/VariableManagement.c b/Library/OcBootManagementLib/VariableManagement.c
@@ -374,9 +374,9 @@ OcDeleteVariables (
   DeleteVariables ();
 
   if ((BootProtect & OC_BOOT_PROTECT_VARIABLE_BOOTSTRAP) != 0) {
-    BootOptionIndex = 0;
+    BootOptionIndex = 1;
     Status = gRT->SetVariable (
-      L"Boot0000",
+      L"Boot0001",
       &gEfiGlobalVariableGuid,
       EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_NON_VOLATILE,
       BootOptionSize,