Readable Listings from avr-as (GNU)

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I was playing with ralphd's bootloader which uses avr-gcc.

 

After the irritation of byte-arithmetic for a word-addressed AVR,   I moved to the Atmel Assembler.

Now I have an intuitive location counter with obvious arithmetic but obviously need to calculate byte-addressing for data in Flash.

 

Anyway,   I am reasonably happy with the project now.    So I thought that I should make it buildable with GCC and Avrasm2.

 

When it comes to produce a listing,   you can use avr-as -ahls=listing.lst or use avr-objdump -S

 

Since avr-as is producing relocatable objects,   the location counter is 0x0000 based.

The avr-objdump will show the absolute locations set by the linker.

 

But the really irritating thing is that the location counter is displayed as high-low and opcodes are displayed as low-high:

listing.lst:

 153 0000 54B7      	    in   rCOUNT, MCUSR

listing.lss:

    in   rCOUNT, MCUSR
 e00:	54 b7       	in	r21, 0x34	; 52

avrasm2.lst

000700 b754          in   rCOUNT, MCUSR
 

I can live with the weird location counter.    I really get upset by an opcode 0xb754 being displayed as "54 b7" or "54B7".

I presume that there is an avr-as switch that shows opcodes properly.     After all,    most MCUs in the world are little-endian.    

 

David.