*From:*Liu, Zhiguang <zhiguang....@intel.com>
*Sent:* 2020年6月15日15:34
*To:* Ard Biesheuvel <ard.biesheu...@arm.com>; Gao, Liming
<liming....@intel.com>; devel@edk2.groups.io
*Cc:* Kinney, Michael D <michael.d.kin...@intel.com>
*Subject:* RE: [edk2-devel] [PATCH v3] MdePkg/BasePrintLib: avoid
absolute addresses for error strings
Hi Ard,
I also collected the image size of OVMFX64 size building with VS2015x86.
Debug
Release
before
after
After-before
before
after
after-before
sec
27664
27409
-255
13968
13968
0
pei
223016
221000
-2016
107208
106984
-224
dxe
4507000
4481336
-25664
2987064
2979384
-7680
compact
1179776
1172528
-7248
922664
920304
-2360
It can reduce the image size in X64.
Reviewed-by: Zhiguang Liu <zhiguang....@intel.com
<mailto:zhiguang....@intel.com>>
-----Original Message-----
From: Ard Biesheuvel <ard.biesheu...@arm.com <mailto:ard.biesheu...@arm.com>>
Sent: Friday, June 12, 2020 11:11 PM
To: Gao, Liming <liming....@intel.com <mailto:liming....@intel.com>>;
devel@edk2.groups.io <mailto:devel@edk2.groups.io>
Cc: Kinney, Michael D <michael.d.kin...@intel.com <mailto:michael.d.kin...@intel.com>>; Liu,
Zhiguang
<zhiguang....@intel.com <mailto:zhiguang....@intel.com>>
Subject: Re: [edk2-devel] [PATCH v3] MdePkg/BasePrintLib: avoid absolute
addresses for error strings
On 6/12/20 4:33 PM, Gao, Liming wrote:
> Ard:
> I will collect the image size on OVMF X64 platform with this patch.
>
Building OvmfPkgX64.dsc in RELEASE mode using GCC5 profile gives me
Before:
SECFV [5%Full] 212992 total, 11760 used, 201232 free PEIFV [9%Full] 917504
total, 89384 used, 828120 free DXEFV [22%Full] 12582912 total, 2806320 used,
9776592 free FVMAIN_COMPACT [26%Full] 3440640 total, 918760 used,
2521880 free
After:
SECFV [5%Full] 212992 total, 11760 used, 201232 free PEIFV [9%Full] 917504
total, 89192 used, 828312 free DXEFV [22%Full] 12582912 total, 2802928 used,
9779984 free FVMAIN_COMPACT [26%Full] 3440640 total, 916784 used,
2523856 free
So no change for SECFV, -192 bytes for PEIFV, -3392 bytes for DXEFV and
-1976 bytes for the resulting outer FV image.
>> -----Original Message-----
>> From: devel@edk2.groups.io <mailto:devel@edk2.groups.io> <devel@edk2.groups.io
<mailto:devel@edk2.groups.io>> On Behalf Of Ard
Biesheuvel
>> Sent: Friday, June 12, 2020 6:35 AM
>> To: devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>> Cc: Ard Biesheuvel <ard.biesheu...@arm.com <mailto:ard.biesheu...@arm.com>>;
Kinney, Michael D
<michael.d.kin...@intel.com <mailto:michael.d.kin...@intel.com>>; Gao,
Liming <liming....@intel.com <mailto:liming....@intel.com>>
>> Subject: [edk2-devel] [PATCH v3] MdePkg/BasePrintLib: avoid absolute
addresses for error strings
>>
>> The mStatusString[] array is constructed as an array of pointer-to-char,
>> which means that on X64 or AARCH64, it is emitted as a single linear list
>> of 64-bit quantities, each containing the absolute address of one of the
>> string literals in memory.
>>
>> This means that each string takes up 8 bytes of additional space, along
>> with 2 bytes of relocation data. It also means that extra work needs to
>> be done at runtime to process these relocations, every time a module is
>> loaded that incorporates this library.
>>
>> So fix both issues, by splitting mStatusString into two arrays of char
>> arrays. The memory footprint decreases from 955 to 843 bytes, and given
>> that in the latter case, the overhead consists of 278 NUL characters rather
>> than 390 bytes worth of absolute addresses and relocation records, the
size
>> of a compressed image is reduced even further. For example, when
building
>> ArmVirtQemu.dsc in RELEASE mode for AARCH64 with the GCC5 profile, I
get:
>>
>> Before
>>
>> FV Space Information
>> FVMAIN [100%Full] 5329920 total, 5329920 used, 0 free
>> FVMAIN_COMPACT [38%Full] 2093056 total, 811840 used, 1281216 free
>>
>> After
>>
>> FV Space Information
>> FVMAIN [100%Full] 5321728 total, 5321728 used, 0 free
>> FVMAIN_COMPACT [38%Full] 2093056 total, 809696 used, 1283360 free
>>
>> So the uncompressed contents of the compressed image are 8 KB smaller,
>> whereas the resulting flash image (consisting of the compressed image
>> along with SEC, PEI_CORE and a set of PEIMs that execute in place) is
>> 2 KB smaller.
>>
>> Cc: "Kinney, Michael D" <michael.d.kin...@intel.com
<mailto:michael.d.kin...@intel.com>>
>> Cc: "Gao, Liming" <liming....@intel.com <mailto:liming....@intel.com>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheu...@arm.com
<mailto:ard.biesheu...@arm.com>>
>> ---
>> v3:
>> - add code comments to explain what the inner dimension of each array is
>> based on
>>
>> v2:
>> - split off this patch from the StandaloneMmPkg series, since they are not
>> interdependent anyway, and so they can be discussed separately
>> - remove mention of StandaloneMmPkg from the commit log - the space
savings
>> by themselves are sufficient justification
>> - update the before/after numbers with the current results
>> - split the warnings and errors into a separate array, so that the latter
>> can use smaller entries
>> - clarify the commit log to explain the effect on compressed as well as
>> XIP images (which both get smaller)
>>
>> MdePkg/Library/BasePrintLib/PrintLibInternal.c | 15 ++++++++++++---
>> 1 file changed, 12 insertions(+), 3 deletions(-)
>>
>> diff --git a/MdePkg/Library/BasePrintLib/PrintLibInternal.c
b/MdePkg/Library/BasePrintLib/PrintLibInternal.c
>> index b6ec5ac4fbb9..50c6e8559c43 100644
>> --- a/MdePkg/Library/BasePrintLib/PrintLibInternal.c
>> +++ b/MdePkg/Library/BasePrintLib/PrintLibInternal.c
>> @@ -27,13 +27,22 @@
>>
>>
>> GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 mHexStr[] =
{'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
>>
>>
>>
>> -GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 * CONST
mStatusString[] = {
>>
>> +//
>>
>> +// Longest string: RETURN_WARN_BUFFER_TOO_SMALL => 24
characters plus NUL byte
>>
>> +//
>>
>> +GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8
mWarningString[][24+1] = {
>>
>> "Success", // RETURN_SUCCESS = 0
>>
>> "Warning Unknown Glyph", // RETURN_WARN_UNKNOWN_GLYPH
= 1
>>
>> "Warning Delete Failure", // RETURN_WARN_DELETE_FAILURE = 2
>>
>> "Warning Write Failure", // RETURN_WARN_WRITE_FAILURE = 3
>>
>> "Warning Buffer Too Small", //
RETURN_WARN_BUFFER_TOO_SMALL = 4
>>
>> "Warning Stale Data", // RETURN_WARN_STALE_DATA = 5
>>
>> +};
>>
>> +
>>
>> +//
>>
>> +// Longest string: RETURN_INCOMPATIBLE_VERSION => 20 characters
plus NUL byte
>>
>> +//
>>
>> +GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8
mErrorString[][20+1] = {
>>
>> "Load Error", // RETURN_LOAD_ERROR = 1 |
MAX_BIT
>>
>> "Invalid Parameter", // RETURN_INVALID_PARAMETER = 2 |
MAX_BIT
>>
>> "Unsupported", // RETURN_UNSUPPORTED = 3 |
MAX_BIT
>>
>> @@ -996,12 +1005,12 @@ BasePrintLibSPrintMarker (
>> //
>>
>> Index = Status & ~MAX_BIT;
>>
>> if (Index > 0 && Index <= ERROR_STATUS_NUMBER) {
>>
>> - ArgumentString = mStatusString [Index +
WARNING_STATUS_NUMBER];
>>
>> + ArgumentString = mErrorString [Index - 1];
>>
>> }
>>
>> } else {
>>
>> Index = Status;
>>
>> if (Index <= WARNING_STATUS_NUMBER) {
>>
>> - ArgumentString = mStatusString [Index];
>>
>> + ArgumentString = mWarningString [Index];
>>
>> }
>>
>> }
>>
>> if (ArgumentString == ValueBuffer) {
>>
>> --
>> 2.26.2
>>
>>
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