[RFA/libgloss/arm] Handle zero heap base from semihosting

[Matthew Gretton-Dann]

On 27/09/11 02:44, Can Finner wrote:
> On Mon, Sep 26, 2011 at 11:27 PM, Matthew Gretton-Dann
> <matthew.gretton-dann@arm.com>  wrote:
>
>>
>> libgloss/ChangeLog:
>>
>> 2011-09-02  Matthew Gretton-Dann<matthew.gretton-dann@arm.com>
>>
>>         * arm/crt0.s: support 0 heap base response from semihosting.
>>
>
> Hi,
>
> For the symbol "__end__".
>   	.word	CommandLine
>   	.word	255
> +.LC31:
> +	.word	__end__
>
> Is there any story why not using "__bss_end__"? In case the program
> can not assuming
> the bss end lies at last of data segment?
>
> Thanks

The default linker script for arm-none-eabi (installed as 
../lib/ldscripts/armelf.x has the following in it:

>   _bss_end__ = . ; __bss_end__ = . ;
>   . = ALIGN(32 / 8);
>   . = ALIGN(32 / 8);
>   __end__ = . ;
>   _end = .; PROVIDE (end = .);

So I'm using __end__ as it is aligned to a 4-byte boundary which the 
heap requires - whereas __bss_end__ may not be.

Thanks,

Matt

-- 
Matthew Gretton-Dann
Principal Engineer, PD Software - Tools, ARM Ltd