[Ltib] Re: Any assembly/8349 experts?

[Kumar Gala]

On Dec 23, 2006, at 4:44 PM, Mark Lacas wrote:

> Hello,
>   Any 8349 (powerpc)/assembly experts out there?
>
> I am trying to understand how the following instructions work.
>
> This is the code that is supposed to reboot the MPC8349 in my mITX  
> box, it doesn't seem to be working.
>
> My system prints "Restart failed" and ends up in the infinite 'for'  
> loop at the end.
>
> If anyone could add comments to the code or explain what is  
> happening it would be greatly appreciated.
>
> Does anyone know of a workaround or fix?

Not exactly sure what this code is doing with OR0/BR0 or why its  
doing it.  What's this from?

If you're trying to have restart work, why not use the RESET module  
in the 834x.

snipped from the linux kernel restart code:

void mpc83xx_restart(char *cmd)
{
#define RST_OFFSET      0x00000900
#define RST_PROT_REG    0x00000018
#define RST_CTRL_REG    0x0000001c
        __be32 __iomem *reg;

        /* map reset register space */
        reg = ioremap(get_immrbase() + 0x900, 0xff);

        local_irq_disable();

        /* enable software reset "RSTE" */
        out_be32(reg + (RST_PROT_REG >> 2), 0x52535445);

        /* set software hard reset */
        out_be32(reg + (RST_CTRL_REG >> 2), 0x2);
        for (;;) ;
}


> Thanks,
> ml
>
> #ifdef CONFIG_MPC8349_ITX
>         local_irq_disable();
>         /* abort(); */
>
>         printk("8349 Restart\n");
>
>         volatile unsigned char  dummy;
>         volatile unsigned int   msr;
>         unsigned int bad_addr, rmr_addr, br0_addr;
>
>         /* Get base address mapped by BR0/OR0 */
>         br0_addr = (unsigned int)(VIRT_IMMRBAR + 0x5000);
>         rmr_addr = (unsigned int)(VIRT_IMMRBAR + 0x0914);
>
>         bad_addr = br0_addr & 0xFFFF8000;
>         cli();
>
>         /* Enable CheckStop Reset */
>         rmr_addr |= 0x00000001;
>
>         /* Invalidate BR0 mapping */
>         br0_addr = 0;
>
>         /* Set MSR and cause reset */
>         __asm__("mfmsr %0" : "=r" (msr) );
>         msr &= ~0x1000;
>         __asm__("mtmsr %0" : "=r" (msr) );
>         dummy = * (unsigned char *) bad_addr;
>         printk("Restart failed\n");
>         for(;;);