tree e63d5e17929b356eac77b2462ea01b2f5ee0a6db
parent c03e15d59e76bb43d314c11a9a8e2119ddcb8850
author Sam Elliott <selliott@lowrisc.org> 1598286582 +0100
committer Sam Elliott <sam@lenary.co.uk> 1598636471 +0100

[sw] Conditionally Provide Some libc Symbols

`memory.h` provides some symbols which are also provided by libc. When
these are used by DIFs, we would prefer to use the host's libc
implementations rather than our own.

This approach is used so that DIFs can depend on `memory.h`, but also be
built for host-side software.

OpenTitan does not access volatile memory using the `memory.h` functions
-- volatile memory must be accessed via the functions in `mmio.h` -- so
this should not affect the functionality of any tests.

Closes #1806.

Signed-off-by: Sam Elliott <selliott@lowrisc.org>