X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=MdePkg%2FLibrary%2FBaseLib%2FX64%2FWriteDr5.asm;fp=MdePkg%2FLibrary%2FBaseLib%2FX64%2FWriteDr5.asm;h=86009c32871d343cb61e728b7065c3e769d1e8ec;hb=a9a812a0ed4ab3d83941fdc6da281aebdb9bb296;hp=91eeef20e334dd83019b0ab1d1b8f035f044e5ba;hpb=741fb364170375f89aa9c29488cc402db07a3776;p=mirror_edk2.git

diff --git a/MdePkg/Library/BaseLib/X64/WriteDr5.asm b/MdePkg/Library/BaseLib/X64/WriteDr5.asm
index 91eeef20e3..86009c3287 100644
--- a/MdePkg/Library/BaseLib/X64/WriteDr5.asm
+++ b/MdePkg/Library/BaseLib/X64/WriteDr5.asm
@@ -31,6 +31,10 @@
 ;   );
 ;------------------------------------------------------------------------------
 AsmWriteDr5 PROC
+    ;
+    ; There's no obvious reason to access this register, since it's aliased to
+    ; DR7 when DE=0 or an exception generated when DE=1
+    ;
     DB      0fh, 23h, 0e9h
     mov     rax, rcx
     ret