eXecute-Only Memory (XOM) is a protection mechanism against some ROP
attacks. XOM sets the code as executable and unreadable, so the access
to any data, like literal pools, in the code section causes the fault
with XOM. The compiler can disable literal pools for C source files,
but not for assembly files, so I use movz/movk instead of literal pools
in start.S for XOM.
I add MOVL macro with movz/movk instructions like movl pseudo-instruction
in armasm, and use the macro instead of literal pools.
* sysdeps/aarch64/start.S: Use MOVL instead of literal pools.
* sysdeps/aarch64/sysdep.h (MOVL): Add MOVL macro.