This was my original email, see below. It has it's own topic. Hopefully it may it's way to the mailer.
On Monday, February 26, 2018 2:39 PM, mark pleso mpleso@yahoo.com wrote:
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. coreboot/src/cpu/x86/mp_init.cstatic void asmlinkage smm_do_relocation(void *arg) { 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);}