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| -rw-r--r-- | Lessons/Lesson_41/README.md | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/Lessons/Lesson_41/README.md b/Lessons/Lesson_41/README.md index 6b68e92..4eb3684 100644 --- a/Lessons/Lesson_41/README.md +++ b/Lessons/Lesson_41/README.md @@ -469,8 +469,17 @@ DiscoverPeimsAndOrderWithApriori(): Found 0x7 PEI FFS files in the 0th FV It is much easier to read now! +# Max string length in `DEBUG` output +There is a limitation to the maximum string length that can be outputed with a `DEBUG` statement. +https://github.com/tianocore/edk2/blob/master/OvmfPkg/Library/PlatformDebugLibIoPort/DebugLib.c: +``` +#define MAX_DEBUG_MESSAGE_LENGTH 0x100 +``` +If the printed sting is longer than this limit, the output would be truncated to the first `MAX_DEBUG_MESSAGE_LENGTH` symbols. Most probably you would notice this by the fact that `\n` symbol at the end of the string would be lost, and the next printed string wouldn't start from the new line. - - +In this case you might consider increasing the aforementioned limit, for this change the value above and recompile OVMF: +``` +build --platform=OvmfPkg/OvmfPkgX64.dsc --arch=X64 --buildtarget=DEBUG --tagname=GCC5 +``` |