2006. 6. 30. 11:37
http://www.arm.com/support/faqdev/1453.html
ARM/Thumb Interworking and 'Unsupported call'
Description
When building an ARM/Thumb Interworking Image, the linker may give messages like:
For SDT 2.50/2.51:
Error: Unsupported call from Thumb code to ARM symbol arm_sub in thumb.o(C$$code). For SDT 2.11a:
Warning: Unsupported call from Thumb code to ARM symbol arm_sub in thumb.o(C$$code). For SDT 2.11:
1 Thumb to ARM interworking calls generated, use '-info interwork' to listInterworking call from Thumb to ARM code symbol arm_sub in thumb.o(C$$code). Solution
These messages indicate that ARM-to-Thumb or Thumb-to-ARM interworking calls have been detected by the linker, but the called routines have not been compiled for interworking. The example above shows a call from the (Thumb) object module thumb.o to the routine arm_sub() in another module.
Even if the link appears to be successful, you should interpret such messages as being errors, because the image may not execute correctly.
For the case above, you should recompile/reassemble for interworking the (C/asm) module(s) containing arm_sub (let's call it FUNC).
If FUNC is a C file, you should recompile it using the option '-apcs /interwork'.
If FUNC is an assembler file, you should:
use the 'INTERWORK' area assembler attribute for these routines e.g. AREA func, CODE, READONLY, INTERWORK
check the called routine (arm_sub) use a BX LR instruction to return.
check the calling routine uses a BL instruction to call the routine arm_sub.
If the use of '-apcs /interwork' (for armcc & tcc) and 'INTERWORK' (for armasm & tasm) is applied consistently in your project, then the linker will generate the correct interworking veneers, and you will no longer see the message(s) above.
If the object file causing the error is supplied by a 3rd party vendor (e.g. an RTOS) which you do not have the source code for, then you may have to ask your supplier to provide suitably recompiled/reassembled object files.
For more details, see the SDT 2.11 User Guide, chapter 12, 'Interworking ARM and Thumb' or the SDT 2.50 User Guide, chapter 7, 'Interworking ARM and Thumb'.
ARM/Thumb Interworking and 'Unsupported call'
Description
When building an ARM/Thumb Interworking Image, the linker may give messages like:
For SDT 2.50/2.51:
Error: Unsupported call from Thumb code to ARM symbol arm_sub in thumb.o(C$$code). For SDT 2.11a:
Warning: Unsupported call from Thumb code to ARM symbol arm_sub in thumb.o(C$$code). For SDT 2.11:
1 Thumb to ARM interworking calls generated, use '-info interwork' to listInterworking call from Thumb to ARM code symbol arm_sub in thumb.o(C$$code). Solution
These messages indicate that ARM-to-Thumb or Thumb-to-ARM interworking calls have been detected by the linker, but the called routines have not been compiled for interworking. The example above shows a call from the (Thumb) object module thumb.o to the routine arm_sub() in another module.
Even if the link appears to be successful, you should interpret such messages as being errors, because the image may not execute correctly.
For the case above, you should recompile/reassemble for interworking the (C/asm) module(s) containing arm_sub (let's call it FUNC).
If FUNC is a C file, you should recompile it using the option '-apcs /interwork'.
If FUNC is an assembler file, you should:
use the 'INTERWORK' area assembler attribute for these routines e.g. AREA func, CODE, READONLY, INTERWORK
check the called routine (arm_sub) use a BX LR instruction to return.
check the calling routine uses a BL instruction to call the routine arm_sub.
If the use of '-apcs /interwork' (for armcc & tcc) and 'INTERWORK' (for armasm & tasm) is applied consistently in your project, then the linker will generate the correct interworking veneers, and you will no longer see the message(s) above.
If the object file causing the error is supplied by a 3rd party vendor (e.g. an RTOS) which you do not have the source code for, then you may have to ask your supplier to provide suitably recompiled/reassembled object files.
For more details, see the SDT 2.11 User Guide, chapter 12, 'Interworking ARM and Thumb' or the SDT 2.50 User Guide, chapter 7, 'Interworking ARM and Thumb'.