* All externally visible functions which should be entered in
Thumb mode must have the .thumb_func pseudo op specified just
* All externally visible functions which should be entered in
Thumb mode must have the .thumb_func pseudo op specified just
When the -mthumb-interwork command line switch is specified, gcc
arranges for all functions to return to their caller by using the BX
instruction. Thus provided that the return address has the bottom bit
When the -mthumb-interwork command line switch is specified, gcc
arranges for all functions to return to their caller by using the BX
instruction. Thus provided that the return address has the bottom bit
(where <name> is the name of the function) which indicates the start
of the Thumb code. This does have the interesting side effect in that
if this function is now called from a Thumb mode piece of code
(where <name> is the name of the function) which indicates the start
of the Thumb code. This does have the interesting side effect in that
if this function is now called from a Thumb mode piece of code
to switch from Thumb mode into ARM mode, and then this is immediately
overridden by the function's header which switches back into Thumb
mode.
to switch from Thumb mode into ARM mode, and then this is immediately
overridden by the function's header which switches back into Thumb
mode.