How to bring up CPU 4~7
来自个人维基
Xen boot error:
... (XEN) Bringing up CPU3 (XEN) CPU3: Guest atomics will try 12 times before pausing the domain (XEN) CPU 3 booted. (XEN) Bringing up CPU4 (XEN) CPU4 MIDR (0x410fd091) does not match boot CPU MIDR (0x410fd034), (XEN) disable cpu (see big.LITTLE.txt under docs/). (XEN) CPU4 never came online (XEN) Failed to bring up CPU 4 (error -5) (XEN) Bringing up CPU5 (XEN) CPU5 MIDR (0x410fd091) does not match boot CPU MIDR (0x410fd034), (XEN) disable cpu (see big.LITTLE.txt under docs/). (XEN) CPU5 never came online (XEN) Failed to bring up CPU 5 (error -5) (XEN) Bringing up CPU6 (XEN) CPU6 MIDR (0x410fd091) does not match boot CPU MIDR (0x410fd034), (XEN) disable cpu (see big.LITTLE.txt under docs/). (XEN) CPU6 never came online (XEN) Failed to bring up CPU 6 (error -5) (XEN) Bringing up CPU7 (XEN) CPU7 MIDR (0x410fd091) does not match boot CPU MIDR (0x410fd034), (XEN) disable cpu (see big.LITTLE.txt under docs/). (XEN) CPU7 never came online (XEN) Failed to bring up CPU 7 (error -5)
Boot sequence:
./xen/arch/arm/smpboot.c
int __cpu_up(unsigned int cpu) { rc = init_secondary_pagetables(cpu); console_start_sync(); /* Secondary may use early_printk */ smp_up_cpu = cpu_logical_map(cpu); clean_dcache(smp_up_cpu); rc = arch_cpu_up(cpu); console_end_sync(); while ( !cpu_online(cpu) && NOW() < deadline )/ { cpu_relax(); process_pending_softirqs(); } /* * Ensure that other cpus' initializations are visible before * proceeding. Corresponds to smp_wmb() in start_secondary. */ smp_rmb(); clean_dcache(smp_up_cpu); if ( !cpu_online(cpu) ) { printk("CPU%d never came online\n", cpu); return -EIO; } } /* Boot the current CPU */ void start_secondary(void) { /* * Currently Xen assumes the platform has only one kind of CPUs. * This assumption does not hold on big.LITTLE platform and may * result to instability and insecure platform (unless cpu affinity * is manually specified for all domains). Better to park them for * now. */ if ( !opt_hmp_unsafe && current_cpu_data.midr.bits != boot_cpu_data.midr.bits ) { printk(XENLOG_ERR "CPU%u MIDR (0x%x) does not match boot CPU MIDR (0x%x),\n" "disable cpu (see big.LITTLE.txt under docs/).\n", smp_processor_id(), current_cpu_data.midr.bits, boot_cpu_data.midr.bits); stop_cpu(); } }