Add support for SuperH/"sh" to nolibc.
Only sh4 is tested for now.
The startup code is special:
__nolibc_entrypoint_epilogue() calls __builtin_unreachable() which emits
a call to abort(). To make this work a function prologue is generated to
set up a GOT pointer which corrupts "sp".
__builtin_unreachable() is necessary for __attribute__((noreturn)).
Also depending on compiler flags (for example -fPIC) even more prologue
is generated.
Work around this by defining a nested function in asm.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70216
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Acked-by: Rob Landley <rob@landley.net>
Acked-by: D. Jeff Dionne <jeff@coresemi.io>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20250623-nolibc-sh-v2-3-0f5b4b303025@weissschuh.net
For the test implementation of the SuperH architecture a second serial
serial port needs to be used. Unfortunately the currently used 'stdio'
driver does not support multiple serial ports at the same time.
Switch to the 'file' driver which does support multiple ports and is
sufficient for the nolibc-test usecase.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20250623-nolibc-sh-v2-2-0f5b4b303025@weissschuh.net
The nolibc tests are not real kselftests, they work differently and
provide a different interface. Users trying to use them like real
selftests may be confused and the tests are not executed by CI systems.
To make space for an integration with the kselftest framework, move the
custom tests out of the way.
The custom tests are still useful to keep as they provide functionality
not provided by kselftests.
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250620-nolibc-selftests-v1-3-f6b2ce7c5071@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
