Has anyone else seen a hang during coreboot booting on a Broadwell-DE? The issue appears to be in mp_init.c, in the function smm_do_relocation(). This is coreboot 4.7, but I think the issue exists in 4.6 as well.
Enabling the printk will stop the hang. Or, just adding a wbinvd() instruction will stop the hang, and things proceed normally. Code is below.
Any help would be appreciated.
btw - This not a commercial motherboard.
{
const struct smm_module_params *p;
const struct smm_runtime *runtime;
int cpu;
uintptr_t curr_smbase;
uintptr_t perm_smbase;
p = arg;
runtime = p->runtime;
cpu = p->cpu;
curr_smbase = runtime->smbase;
if (cpu >= CONFIG_MAX_CPUS) {
printk(BIOS_CRIT,
"Invalid CPU number assigned in SMM stub: %d\n", cpu);
return;
}
/*
* The permanent handler runs with all cpus concurrently. Precalculate
* the location of the new SMBASE. If using SMM modules then this
* calculation needs to match that of the module loader.
*/
perm_smbase = mp_state.perm_smbase;
perm_smbase -= cpu * runtime->save_state_size;
printk(BIOS_DEBUG, "New SMBASE 0x%08lx\n", perm_smbase);
/* write cache to DRAM before calling relocation handler */ /* will stop hang */
wbinvd(); /* <<=== OR NEW INSTRUCTION w/o printk STOPS HANG */
/* Setup code checks this callback for validity. */
mp_state.ops.relocation_handler(cpu, curr_smbase, perm_smbase);
}