[PATCH 1/2] OvmfPkg/PlatformPei: explain EFI_MEMORY_TYPE_INFORMATION page counts

["Laszlo Ersek" <lersek@redhat.com>]

Add a code comment that explains the nature of the NumberOfPages field
values. Including this kind of historical information was suggested by
Leif in <https://edk2.groups.io/g/devel/message/55797> (alternative link:
<http://mid.mail-archive.com/20200312104006.GB23627@bivouac.eciton.net>).

Right now, the most recent commit updating the page counts has been commit
991d95636264 ("[...] Update default memory type information to reduce EFI
Memory Map fragmentation.", 2010-07-16).

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Suggested-by: Leif Lindholm <leif@nuviainc.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 OvmfPkg/PlatformPei/MemTypeInfo.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/OvmfPkg/PlatformPei/MemTypeInfo.c b/OvmfPkg/PlatformPei/MemTypeInfo.c
index c709236a457a..863c6f382680 100644
--- a/OvmfPkg/PlatformPei/MemTypeInfo.c
+++ b/OvmfPkg/PlatformPei/MemTypeInfo.c
@@ -19,6 +19,12 @@
 
 #include "Platform.h"
 
+//
+// The NumberOfPages values below are ad-hoc. They are updated sporadically at
+// best (please refer to git-blame for past updates). The values capture a set
+// of BIN hints that made sense at a particular time, for some (now likely
+// unknown) workloads / boot paths.
+//
 STATIC EFI_MEMORY_TYPE_INFORMATION mDefaultMemoryTypeInformation[] = {
   { EfiACPIMemoryNVS,       0x004 },
   { EfiACPIReclaimMemory,   0x008 },
-- 
2.19.1.3.g30247aa5d201