[fpc-devel] How can I distribute code in two different memory areas? (.section)

[Michael Ring]

Unfortunately that does not seem to work (or I use it wrong):

This procedure:

procedure _general_exception_handler; assembler; nostackframe; public 
name '_GENERAL_EXCEPTION_HANDLER';
asm
   .section "reset"
   sdbbp 0;
   .Lloopb:
    b .Lloopb
end;

translates to:

.section .text.n_pic32mx1xxfxxxc_$$__general_exception_handler
         .balign 4
.globl  PIC32MX1XXFXXXC_$$__GENERAL_EXCEPTION_HANDLER
         .type PIC32MX1XXFXXXC_$$__GENERAL_EXCEPTION_HANDLER, at function
PIC32MX1XXFXXXC_$$__GENERAL_EXCEPTION_HANDLER:
.globl  _GENERAL_EXCEPTION_HANDLER
         .type   _GENERAL_EXCEPTION_HANDLER, at function
_GENERAL_EXCEPTION_HANDLER:
         .ent    PIC32MX1XXFXXXC_$$__GENERAL_EXCEPTION_HANDLER

.section reset
         sdbbp   0
.Lj11:
         b       .Lj11
         jr      $ra
         nop
         .set    macro
         .set    reorder
         .end    PIC32MX1XXFXXXC_$$__GENERAL_EXCEPTION_HANDLER
.Lt3:
.Le2:
         .size   PIC32MX1XXFXXXC_$$__GENERAL_EXCEPTION_HANDLER, .Le2 - 
PIC32MX1XXFXXXC_$$__GENERAL_EXCEPTION_HANDLER
.Ll8:

which creates an assembler error:

/Users/ring/devel/fpc/rtl/units/mipsel-embedded/pic32mx1xxfxxxc.s:94: 
Error: operation combines symbols in different segments

the error is from the .size line.



Am 02.06.13 22:51, schrieb Jeppe Græsdal Johansen:
> Den 02-06-2013 22:41, Michael Ring skrev:
>> Hi, perhaps I am overseeing a simple solution for my problem:
>>
>> On the pic32 there are two flash areas, one at 0x9d000000 for the 
>> main program and another at 0xbfc00000 that is called Boot Flash. On 
>> reset the program starts in the boot flash at the first address.
>>
>> I have written the startup code for the chips now but I need to 
>> distribute some procedures between the two memory areas, for obvious 
>> reasons I must have some code at address 0xbfc00000 or the chip will 
>> not boot correctly ;-).
>>
>> My thought was now to tweak the linker script in the same way the 
>> original linker scripts of pic32 work:
>>
>> MEMORY
>> {
>>   kseg0_program_mem    (rx)  : ORIGIN = 0x9D000000, LENGTH = 0x80000
>>   kseg1_boot_mem             : ORIGIN = 0xBFC00000, LENGTH = 0x490
>> }
>>
>> SECTIONS
>> {
>>   .reset _RESET_ADDR :
>>   {
>>     KEEP(*(.reset))
>>     KEEP(*(.reset.startup))
>>   } > kseg1_boot_mem
>> }
>>
>> In assembler I can then simply write:
>>  .section .reset,code and
>>  .section .reset.startup,code
>>
>> and then the code, this will automagically end up in the 
>> kseg1_boot_mem, but this does not work with the inline assembler. Any 
>> ideas on how to do this the correct way? Is there something more 
>> intelligent than to write a plain assembler file?
>>
>> TnX,
>>
>> Michael
>
> You should be able to use
> .section ".reset"
>
>
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