1. Added comments to ASM files

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / ReadDr5.asm

diff --git a/MdePkg/Library/BaseLib/X64/ReadDr5.asm b/MdePkg/Library/BaseLib/X64/ReadDr5.asm
index 0582502220803c163dc35af5ae4ab88ce8f337e0..3bee3a56ec4410786a1e723638a1b724c2be72f1 100644 (file)
--- a/MdePkg/Library/BaseLib/X64/ReadDr5.asm
+++ b/MdePkg/Library/BaseLib/X64/ReadDr5.asm
@@ -31,6 +31,10 @@
 ;   );\r
 ;------------------------------------------------------------------------------\r
 AsmReadDr5  PROC\r
+    ;\r
+    ; There's no obvious reason to access this register, since it's aliased to\r
+    ; DR7 when DE=0 or an exception generated when DE=1\r
+    ;\r
     DB      0fh, 21h, 0e8h\r
     ret\r
 AsmReadDr5  ENDP\r