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Diffstat (limited to 'doc/manual/building.rst')
| -rw-r--r-- | doc/manual/building.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/doc/manual/building.rst b/doc/manual/building.rst index 49dc5aa01..dbd6ff422 100644 --- a/doc/manual/building.rst +++ b/doc/manual/building.rst @@ -255,6 +255,20 @@ executed on a browser, use:: em++ -s ALLOW_MEMORY_GROWTH=1 -s DISABLE_EXCEPTION_CATCHING=0 -s WASM=1 \ --preload-file src/tests/data botan-test.bc -o botan-test.html +Supporting Older Distros +^^^^^^^^^^^^^^^^^^^^^^^^^ + +Some "stable" distributions, notably RHEL/CentOS, ship very obsolete +versions of binutils, which do not support more recent CPU instructions. +As a result when building you may receive errors like:: + + Error: no such instruction: `sha256rnds2 %xmm0,%xmm4,%xmm3' + +Depending on how old your binutils is, you may need to disable BMI2, +AVX2, SHA-NI, and/or RDSEED. These can be disabled by passing the +flags ``--disable-bmi2``, ``--disable-avx2``, ``--disable-sha-ni``, +and ``--disable-rdseed`` to ``configure.py``. + Other Build-Related Tasks ---------------------------------------- |