I was wondering what would happen if we converted the CHAR8 arrays in to strings with multiple nulls [1]. Looks like it saves space in uncompressed FVs, but not in compressed FVs.
diff --git a/MdePkg/Library/BasePrintLib/PrintLibInternal.c b/MdePkg/Library/BasePrintLib/PrintLibInternal.c
index 50c6e8559c43..db2533e7affb 100644
--- a/MdePkg/Library/BasePrintLib/PrintLibInternal.c
+++ b/MdePkg/Library/BasePrintLib/PrintLibInternal.c
@@ -30,53 +30,73 @@ GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 mHexStr[] = {'0','1','2','3','4','5','
//
// 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
-};
+GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 *mWarningString = \
+ "Success\0" /* RETURN_SUCCESS = 0 */ \
+ "Warning Unknown Glyph\0" /* RETURN_WARN_UNKNOWN_GLYPH = 1 */ \
+ "Warning Delete Failure\0" /* RETURN_WARN_DELETE_FAILURE = 2 */ \
+ "Warning Write Failure\0" /* RETURN_WARN_WRITE_FAILURE = 3 */ \
+ "Warning Buffer Too Small\0" /* 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
- "Bad Buffer Size", // RETURN_BAD_BUFFER_SIZE = 4 | MAX_BIT
- "Buffer Too Small", // RETURN_BUFFER_TOO_SMALL, = 5 | MAX_BIT
- "Not Ready", // RETURN_NOT_READY = 6 | MAX_BIT
- "Device Error", // RETURN_DEVICE_ERROR = 7 | MAX_BIT
- "Write Protected", // RETURN_WRITE_PROTECTED = 8 | MAX_BIT
- "Out of Resources", // RETURN_OUT_OF_RESOURCES = 9 | MAX_BIT
- "Volume Corrupt", // RETURN_VOLUME_CORRUPTED = 10 | MAX_BIT
- "Volume Full", // RETURN_VOLUME_FULL = 11 | MAX_BIT
- "No Media", // RETURN_NO_MEDIA = 12 | MAX_BIT
- "Media changed", // RETURN_MEDIA_CHANGED = 13 | MAX_BIT
- "Not Found", // RETURN_NOT_FOUND = 14 | MAX_BIT
- "Access Denied", // RETURN_ACCESS_DENIED = 15 | MAX_BIT
- "No Response", // RETURN_NO_RESPONSE = 16 | MAX_BIT
- "No mapping", // RETURN_NO_MAPPING = 17 | MAX_BIT
- "Time out", // RETURN_TIMEOUT = 18 | MAX_BIT
- "Not started", // RETURN_NOT_STARTED = 19 | MAX_BIT
- "Already started", // RETURN_ALREADY_STARTED = 20 | MAX_BIT
- "Aborted", // RETURN_ABORTED = 21 | MAX_BIT
- "ICMP Error", // RETURN_ICMP_ERROR = 22 | MAX_BIT
- "TFTP Error", // RETURN_TFTP_ERROR = 23 | MAX_BIT
- "Protocol Error", // RETURN_PROTOCOL_ERROR = 24 | MAX_BIT
- "Incompatible Version", // RETURN_INCOMPATIBLE_VERSION = 25 | MAX_BIT
- "Security Violation", // RETURN_SECURITY_VIOLATION = 26 | MAX_BIT
- "CRC Error", // RETURN_CRC_ERROR = 27 | MAX_BIT
- "End of Media", // RETURN_END_OF_MEDIA = 28 | MAX_BIT
- "Reserved (29)", // RESERVED = 29 | MAX_BIT
- "Reserved (30)", // RESERVED = 30 | MAX_BIT
- "End of File", // RETURN_END_OF_FILE = 31 | MAX_BIT
- "Invalid Language", // RETURN_INVALID_LANGUAGE = 32 | MAX_BIT
- "Compromised Data" // RETURN_COMPROMISED_DATA = 33 | MAX_BIT
-};
+GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 *mErrorString = \
+ "Load Error\0" /* RETURN_LOAD_ERROR = 1 | MAX_BIT */ \
+ "Invalid Parameter\0" /* RETURN_INVALID_PARAMETER = 2 | MAX_BIT */ \
+ "Unsupported\0" /* RETURN_UNSUPPORTED = 3 | MAX_BIT */ \
+ "Bad Buffer Size\0" /* RETURN_BAD_BUFFER_SIZE = 4 | MAX_BIT */ \
+ "Buffer Too Small\0" /* RETURN_BUFFER_TOO_SMALL, = 5 | MAX_BIT */ \
+ "Not Ready\0" /* RETURN_NOT_READY = 6 | MAX_BIT */ \
+ "Device Error\0" /* RETURN_DEVICE_ERROR = 7 | MAX_BIT */ \
+ "Write Protected\0" /* RETURN_WRITE_PROTECTED = 8 | MAX_BIT */ \
+ "Out of Resources\0" /* RETURN_OUT_OF_RESOURCES = 9 | MAX_BIT */ \
+ "Volume Corrupt\0" /* RETURN_VOLUME_CORRUPTED = 10 | MAX_BIT */ \
+ "Volume Full\0" /* RETURN_VOLUME_FULL = 11 | MAX_BIT */ \
+ "No Media\0" /* RETURN_NO_MEDIA = 12 | MAX_BIT */ \
+ "Media changed\0" /* RETURN_MEDIA_CHANGED = 13 | MAX_BIT */ \
+ "Not Found\0" /* RETURN_NOT_FOUND = 14 | MAX_BIT */ \
+ "Access Denied\0" /* RETURN_ACCESS_DENIED = 15 | MAX_BIT */ \
+ "No Response\0" /* RETURN_NO_RESPONSE = 16 | MAX_BIT */ \
+ "No mapping\0" /* RETURN_NO_MAPPING = 17 | MAX_BIT */ \
+ "Time out\0" /* RETURN_TIMEOUT = 18 | MAX_BIT */ \
+ "Not started\0" /* RETURN_NOT_STARTED = 19 | MAX_BIT */ \
+ "Already started\0" /* RETURN_ALREADY_STARTED = 20 | MAX_BIT */ \
+ "Aborted\0" /* RETURN_ABORTED = 21 | MAX_BIT */ \
+ "ICMP Error\0" /* RETURN_ICMP_ERROR = 22 | MAX_BIT */ \
+ "TFTP Error\0" /* RETURN_TFTP_ERROR = 23 | MAX_BIT */ \
+ "Protocol Error\0" /* RETURN_PROTOCOL_ERROR = 24 | MAX_BIT */ \
+ "Incompatible Version\0" /* RETURN_INCOMPATIBLE_VERSION = 25 | MAX_BIT */ \
+ "Security Violation\0" /* RETURN_SECURITY_VIOLATION = 26 | MAX_BIT */ \
+ "CRC Error\0" /* RETURN_CRC_ERROR = 27 | MAX_BIT */ \
+ "End of Media\0" /* RETURN_END_OF_MEDIA = 28 | MAX_BIT */ \
+ "Reserved (29)\0" /* RESERVED = 29 | MAX_BIT */ \
+ "Reserved (30)\0" /* RESERVED = 30 | MAX_BIT */ \
+ "End of File\0" /* RETURN_END_OF_FILE = 31 | MAX_BIT */ \
+ "Invalid Language\0" /* RETURN_INVALID_LANGUAGE = 32 | MAX_BIT */ \
+ "Compromised Data"; /* RETURN_COMPROMISED_DATA = 33 | MAX_BIT */
+
+
+CONST CHAR8 *
+FindNthStr (
+ IN CONST CHAR8 *Start,
+ IN UINTN Index
+ )
+{
+ CONST CHAR8 *str;
+
+ for (str = Start; Index > 0; str++) {
+ if (*str == '\0') {
+ Index--;
+ if (Index == 0) {
+ str++;
+ break;
+ }
+ }
+ }
+
+ return str;
+}
/**
@@ -1005,12 +1025,12 @@ BasePrintLibSPrintMarker (
//
Index = Status & ~MAX_BIT;
if (Index > 0 && Index <= ERROR_STATUS_NUMBER) {
- ArgumentString = mErrorString [Index - 1];
+ ArgumentString = FindNthStr (mErrorString, Index - 1);
}
} else {
Index = Status;
if (Index <= WARNING_STATUS_NUMBER) {
- ArgumentString = mWarningString [Index];
+ ArgumentString = FindNthStr (mWarningString, Index);
}
}
if (ArgumentString == ValueBuffer) {
Thanks,
Andrew Fish
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.
> -----Original Message-----
> Sent: Friday, June 12, 2020 11:11 PM
> 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-----
> Biesheuvel
> >> Sent: Friday, June 12, 2020 6:35 AM
> >> 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.
> >>
> >> ---
> >> 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
> >>
> >>
> >> -=-=-=-=-=-=
> >> Groups.io Links: You receive all messages sent to this group. > >>
> >> View/Reply Online (#61170):
> >> -=-=-=-=-=-=
> >