Hi :
I tried your approach last ight, (in fact I copied part of the
do_reboot() code from u-boot and put it in m8260_restart() function in
the kernel). The only difference is the first line,
volatile immap_t *immap = (immap_t *) IMAP_ADDR;
in my case it is
volatile immap_t * immap = cpm2_immr;
I am using different source tree.
it simply hangs, rather then reset.
On 7/19/06, Wolfgang Denk <wd at denx.de> wrote:
> In message <4879B0C6C249214CBE7AB04453F84E4D050B0F at
> zch01exm20.fsl.freescale.net> you wrote:
> >
> > > command cause machine check and kernel ooops. The problem seems in
> > > the "m8260_gorom" in head.S. The restart() function in m8260_setup.c
> > > passed 2 parameters to that assembly code, r3 is the bd_info , r4 is
> > > the warm start address, I changed it to 0xFF800100, that's where the
> > > u-boot's _start_warm lives, I have verified that address by typing "g
> > > ff800100" in u-boot console, which cause the board reset.
> >
> > Are you sure ff800100 is _start_warm lives? In latest u-boot
>
> Trying to jump to some boot rom address is IMHO always a bad approach
> to reboot a system. You should always try to cause a reset condition
> for the CPU, and thus for all the associated hardware. On 8xx / 8260
> systems this is usually done by going through a machine check. We
> have the following code in our linuxppc_2_4_devel tree, which works
> on ALL 8260 systems, no matter whioch boot loder they use:
>
> static void
> m8260_restart(char *cmd)
> {
> __volatile__ unsigned char dummy;
> ulong msr;
>
> cli();
> volatile immap_t *immap = (immap_t *) IMAP_ADDR;
>
> immap->im_clkrst.car_rmr = 1; /* Checkstop Reset enable */
>
> /* Interrupts and MMU off */
> __asm__ __volatile__ ("mfmsr %0":"=r" (msr):);
>
> msr &= ~(MSR_ME | MSR_EE | MSR_IR | MSR_DR);
> __asm__ __volatile__ ("mtmsr %0"::"r" (msr));
>
> dummy = ((immap_t *)IMAP_ADDR)->im_clkrst.res[0];
>
> printk("Restart failed\n");
> for (;;);
> }
>
>
> Best regards,
>
> Wolfgang Denk
>
> --
> Software Engineering: Embedded and Realtime Systems, Embedded Linux
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> If a group of N persons implements a COBOL compiler, there will be
> N-1 passes. Someone in the group has to be the manager. - T. Cheatham
>
