set arm fallback-mode (arm|thumb|auto)
gdb uses the symbol table, when available, to determine whether instructions
are ARM or Thumb. This command controls gdb’s default behavior when the
symbol table is not available. The default is ‘auto’, which causes gdb to use
the current execution mode (from the T bit in the CPSR register).
set arm force-mode (arm|thumb|auto)
This command overrides use of the symbol table to determine whether instructions
are ARM or Thumb. The default is ‘auto’, which causes gdb to use the
symbol table and then the setting of ‘set arm fallback-mode’.