[OpenBIOS] [PATCH 2/4] ppc: add new context handler

[Programmingkid]

On May 1, 2016, at 6:23 AM, Mark Cave-Ayland wrote:
> 
> +/* Switch to another context. */
> +struct context *switch_to(struct context *ctx)
> +{
> +    volatile struct context *save;
> +    struct context *ret;
> +    unsigned int lr;
> +
> +    debug("switching to new context:\n");
> +    save = __context;
> +    __context = ctx;
> +
> +    asm __volatile__ ("mflr %0\n\t" : "=r" (lr) : : );

This line breaks compatibility with gcc 4.2.3. A simple fix is this:
      asm __volatile__ ("mflr %0\n\t" : "=r" (lr));
	            
			and this

> +    asm __volatile__ ("mtlr %0\n\t" : : "r" (lr) : );
      asm __volatile__ ("mtlr %0\n\t" : : "r" (lr));