1. Added comments to ASM files

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / WriteDr4.asm

diff --git a/MdePkg/Library/BaseLib/X64/WriteDr4.asm b/MdePkg/Library/BaseLib/X64/WriteDr4.asm
index ad618f1089aa7dda9f64cb8681b8f1078aeb6628..188a9d4ddcd5d80e13bcc57c6750762f287dd4d3 100644 (file)
--- a/MdePkg/Library/BaseLib/X64/WriteDr4.asm
+++ b/MdePkg/Library/BaseLib/X64/WriteDr4.asm
@@ -31,6 +31,10 @@
 ;   );\r
 ;------------------------------------------------------------------------------\r
 AsmWriteDr4 PROC\r
+    ;\r
+    ; There's no obvious reason to access this register, since it's aliased to\r
+    ; DR6 when DE=0 or an exception generated when DE=1\r
+    ;\r
     DB      0fh, 23h, 0e1h\r
     mov     rax, rcx\r
     ret\r