The first patch modifying Xtensa libisa has already been
posted in https://lore.kernel.org/qemu-devel/20241204202602.58083-1-philmd@linaro.org/

Philippe Mathieu-Daudé (2):
  target/xtensa: Implement xtensa_isa_is_big_endian()
  target/xtensa: Remove tswap() calls in semihosting simcall() helper

 include/hw/xtensa/xtensa-isa.h |  1 +
 target/xtensa/xtensa-isa.c     |  7 +++++++
 target/xtensa/xtensa-semi.c    | 16 ++++++++++++++--
 3 files changed, 22 insertions(+), 2 deletions(-)

-- 
2.45.2