Hi : The following is the version I am using, it's pretty much same as do_reset() code in u-boot -1.1.4 for m8260 target. However the machine just hangs. I wonder if there are any difference between Power on Reset and Hard reset? in my case maybe the machine did get reset, but the u-boot didn't get executed correctly in the case of hard reset ? It doesn't explain the fact that i can run "reset" in u-boot console though.
Any comments are highly appreciated! I am stucked in here now. m8260_restart(char * cmd) uint startaddr; unsigned long msr; char badval; volatile cpm2_map_t *immap = cpm2_immr; /* Enable CheckStop reset. */ immap->im_clkrst.car_rmr |= 0x00000001; /* 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)); startaddr = 0x04400000; /* this is taken from u-boot-1.1.4 */ /* Access bad address.*/ ((void (*)(void)) startaddr) (); return 1; } 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 >