Re: [avr-chat] gnu-as: Error: invalid sections for operation on `ConfigDescriptor' and `L0
'

[Erik Christiansen]

On Wed, May 25, 2005 at 12:44:16PM +0200, Jörgen Birkler wrote:
> Command line:
> avr-gcc -c -mmcu=atmega8 -I. -x assembler-with-cpp -save-temps
> -Wa,-ahlms=USB2RS232.lst, -gstabs  USB2RS232.s -o
> 
> Errors:
> USB2RS232.s:1676: Error: invalid sections for operation on `StatusAnswer'
> and `L0
'
> USB2RS232.s:1677: Error: invalid sections for operation on `StatusAnswer'
> and `L0
'
> 
> 
> Offending line example:
> -----
> ComposeGET_STATUS2:
>               ldi     ZH, high_rom(StatusAnswer<<1)   ;ROMpointer to  answer
>               ldi     ZL,  low(StatusAnswer<<1)
>               rjmp    ComposeEndXXXDescriptor         ;and complete
> 
> -----
> Defines:
> #define high_rom(x) ((x)>>8)
> #define low(x) ((x) & 0xFF)
> 

Jörgen,

   The situation is much much simpler than it appears. :-)

   Please replace

   ldi   ZH, high_rom(StatusAnswer<<1)

   with

   ldi   ZH, hi8(StatusAnswer)

   Then the error should vanish. Your two problems are summarised in a
note I wrote to myself:

Debug: "Error: invalid sections for operation on `L0' and `some_progmem_label'"
Cause: ldi   ZH,hi8(some_progmem_label<<1)       OR
       ldi   ZL,pm_lo8(2*some_progmem_label)
Diagn: IAR has only high/low modifiers, and needs the manual <<1 hack.
Fix:   GCC has two modifier pairs, used as follows:                      
       hi8/lo8 treat the data or progmem label as a byte address, e.g. for use
       with lpm. (So manual doubling, as in Atmel examples, is harmful.)
       pm_hi8/pm_lo8 treat the progmem label as byte_address/2, e.g. for use
       with icall.               

   Given that, I doubt you'll have much doubt about when to use which,
seeing you've gone as far as providing operators of your own, but a
quick look at the resulting list file quickly sorts that out.

hth,
Erik