Hi Bin,
After adding CONFIG_SFI=y to the kernel config, I was able to see both CPUs in the kernel boot, but now the kernel hangs at boot time. It did not hang when CONFIG_SFI was not set. and if I boot the CONFIG_SFI=y kernel using EFI BIOS it does not hang either. I have repeated the test a few times with the same results each time. I have enclosed the kernel boot log if you can see anything, or have any more suggestions.
Thanks, Tom
******* kernel bootlog *************
U-Boot 2015.07-rc2 (Jun 10 2015 - 09:48:35 -0400) gcc (GCC) 4.8.3 20140911 (Red Hat 4.8.3-9) GNU ld version 2.23.52.0.1-16.el7 20130226
bootargs= root=/dev/ram rw ramdisk_size=300000 console=ttyS0,115200 Using RTL8169#0 device TFTP from server 10.40.101.102; our IP address is 10.40.101.212 Filename 'atom_64/kernel'. Load address: 0x10000000 Loading: ################################################## 5.6 MiB 3.6 MiB/s done Bytes transferred = 5861312 (596fc0 hex) Using RTL8169#0 device TFTP from server 10.40.101.102; our IP address is 10.40.101.212 Filename 'atom_64/ramdisk'. Load address: 0x20000000 Loading: ################################################## 29.1 MiB 3.6 MiB/s done Bytes transferred = 30497951 (1d15c9f hex) Valid Boot Flag Setup Size = 0x00003e00 Magic signature found Using boot protocol version 2.0c Linux kernel version 3.10.62-ltsi-WR6.0.0.20_standard (tbeaman@wocket) #1 SMP PREEMPT Wed Jun 17 15:19:47 EDT 2015 Building boot_params at 0x00090000 Loading bzImage at address 100000 (5845440 bytes) Magic signature found Initial RAM disk at linear address 0x20000000, size 67108864 bytes Kernel command line: " root=/dev/ram rw ramdisk_size=300000 console=ttyS0,115200"
Starting kernel ...
Timer summary in microseconds: Mark Elapsed Stage 0 0 reset 107,427 107,427 board_init_r 1,946,048 1,838,621 id=64 1,948,082 2,034 id=65 1,954,410 6,328 main_loop 7,960,693 6,006,283 id=80 7,960,695 2 eth_start 7,960,825 130 bootp_start 8,947,233 986,408 bootp_stop 8,947,240 7 id=81 8,947,376 136 id=82 8,967,941 20,565 tftp_start 10,541,240 1,573,299 id=84 10,541,242 2 tftp_done 18,606,478 8,065,236 start_kernel
Accumulated time: 330,199 ahci 1,388,929 vesa display Initializing cgroup subsys cpuset Initializing cgroup subsys cpu Initializing cgroup subsys cpuacct Linux version 3.10.62-ltsi-WR6.0.0.20_standard (tbeaman@wocket) (gcc version 4.8.1 (Wind River Linux Sourcery CodeBench 4.8-44) ) #1 SMP PREEMPT Wed Jun 17 15:19:47 EDT 2015 Command line: root=/dev/ram rw ramdisk_size=300000 console=ttyS0,115200 KERNEL supported cpus: Intel GenuineIntel AMD AuthenticAMD Centaur CentaurHauls e820: BIOS-provided physical RAM map: BIOS-e820: [mem 0x0000000000000000-0x000000000009ffff] usable BIOS-e820: [mem 0x00000000000a0000-0x00000000000fffff] reserved BIOS-e820: [mem 0x0000000000100000-0x000000007adfffff] usable BIOS-e820: [mem 0x000000007ae00000-0x000000007fffffff] reserved NX (Execute Disable) protection: active DMI not present or invalid. No AGP bridge found e820: last_pfn = 0x7ae00 max_arch_pfn = 0x400000000 x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106 __next_free_mem_range: Usage of MAX_NUMNODES is depricated. Use NUMA_NO_NODE instead Scanning 1 areas for low memory corruption init_memory_mapping: [mem 0x00000000-0x000fffff] init_memory_mapping: [mem 0x7ac00000-0x7adfffff] init_memory_mapping: [mem 0x78000000-0x7abfffff] init_memory_mapping: [mem 0x00100000-0x77ffffff] RAMDISK: [mem 0x20000000-0x23ffffff] ACPI BIOS Bug: Error: A valid RSDP was not found (20130328/tbxfroot-218) No NUMA configuration found Faking a node at [mem 0x0000000000000000-0x000000007adfffff] Initmem setup node 0 [mem 0x00000000-0x7adfffff] NODE_DATA [mem 0x7adfe000-0x7adfffff] Zone ranges: DMA [mem 0x00001000-0x00ffffff] DMA32 [mem 0x01000000-0xffffffff] Normal empty Movable zone start for each node Early memory node ranges node 0: [mem 0x00001000-0x0009ffff] node 0: [mem 0x00100000-0x7adfffff] x86/hpet: Will disable the HPET for this platform because it's not reliable SFI: Simple Firmware Interface v0.81 http://simplefirmware.org SFI: SYST F0070, 0030 (v1 U-Boot Table v1) SFI: CPUS F0000, 0020 (v1 U-Boot Table v1) SFI: APIC F0020, 0020 (v1 U-Boot Table v1) SFI: XSDT F0040, 0024 (v1 U-Boot Table v1) SFI: registering lapic[0] SFI: registering lapic[4] IOAPIC[0]: apic_id 0, version 32, address 0xfec00000, GSI 0-86 smpboot: Allowing 2 CPUs, 0 hotplug CPUs PM: Registered nosave memory: 00000000000a0000 - 0000000000100000 e820: [mem 0x80000000-0xffffffff] available for PCI devices setup_percpu: NR_CPUS:256 nr_cpumask_bits:256 nr_cpu_ids:2 nr_node_ids:1 PERCPU: Embedded 26 pages/cpu @ffff88007aa00000 s76352 r8192 d21952 u1048576 Built 1 zonelists in Node order, mobility grouping on. Total pages: 495313 Policy zone: DMA32 Kernel command line: root=/dev/ram rw ramdisk_size=300000 console=ttyS0,115200 PID hash table entries: 4096 (order: 3, 32768 bytes) Checking aperture... No AGP bridge found Memory: 1898596k/2013184k available (7917k kernel code, 388k absent, 114200k reserved, 5204k data, 1148k init) SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1 Preemptible hierarchical RCU implementation. RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=2. NR_IRQS:16640 nr_irqs:512 16 Console: colour dummy device 80x25 console [ttyS0] enabled allocated 8388608 bytes of page_cgroup please try 'cgroup_disable=memory' option if you don't want memory cgroups tsc: Fast TSC calibration using PIT tsc: Detected 1333.386 MHz processor Calibrating delay loop (skipped), value calculated using timer frequency.. 2666.77 BogoMIPS (lpj=1333386) pid_max: default: 32768 minimum: 301 Security Framework initialized Dentry cache hash table entries: 262144 (order: 9, 2097152 bytes) Inode-cache hash table entries: 131072 (order: 8, 1048576 bytes) Mount-cache hash table entries: 256 Initializing cgroup subsys debug Initializing cgroup subsys memory Initializing cgroup subsys devices Initializing cgroup subsys freezer Initializing cgroup subsys net_cls Initializing cgroup subsys blkio CPU: Physical Processor ID: 0 CPU: Processor Core ID: 0 ENERGY_PERF_BIAS: Set to 'normal', was 'performance' ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8) mce: CPU supports 6 MCE banks CPU0: Thermal monitoring enabled (TM1) Last level iTLB entries: 4KB 0, 2MB 0, 4MB 0 Last level dTLB entries: 4KB 128, 2MB 0, 4MB 0 tlb_flushall_shift: 6 Freeing SMP alternatives: 28k freed ftrace: allocating 28889 entries in 113 pages ..TIMER: vector=0x30 apic1=-1 pin1=-1 apic2=-1 pin2=-1 ...trying to set up timer as Virtual Wire IRQ... ..... works. smpboot: CPU0: Intel(R) Atom(TM) CPU E3825 @ 1.33GHz (fam: 06, model: 37, stepping: 03) Performance Events: PEBS fmt2+, 8-deep LBR, Silvermont events, full-width counters, Intel PMU driver. ... version: 3 ... bit width: 40 ... generic registers: 2 ... value mask: 000000ffffffffff ... max period: 000000ffffffffff ... fixed-purpose events: 3 ... event mask: 0000000700000003 smpboot: Booting Node 0, Processors #1 OK NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter. Brought up 2 CPUs smpboot: Total of 2 processors activated (5333.54 BogoMIPS) devtmpfs: initialized xor: measuring software checksum speed prefetch64-sse: 4420.000 MB/sec generic_sse: 3988.000 MB/sec xor: using function: prefetch64-sse (4420.000 MB/sec) pinctrl core: initialized pinctrl subsystem SFI: SFI sysfs interfaces init success NET: Registered protocol family 16 PCI: Using configuration type 1 for base access bio: create slab <bio-0> at 0 raid6: sse2x1 453 MB/s raid6: sse2x2 507 MB/s raid6: sse2x4 863 MB/s raid6: using algorithm sse2x4 (863 MB/s) raid6: using ssse3x2 recovery algorithm ACPI: Interpreter disabled. vgaarb: loaded SCSI subsystem initialized usbcore: registered new interface driver usbfs usbcore: registered new interface driver hub usbcore: registered new device driver usb pps_core: LinuxPPS API ver. 1 registered pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti giometti@linux.it PTP clock support registered PCI: Probing PCI hardware PCI host bridge to bus 0000:00 pci_bus 0000:00: root bus resource [io 0x0000-0xffff] pci_bus 0000:00: root bus resource [mem 0x00000000-0xfffffffff] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff] vgaarb: device added: PCI:0000:00:02.0,decodes=io+mem,owns=io+mem,locks=none pci 0000:00:1c.0: PCI bridge to [bus 01] pci 0000:00:1c.2: PCI bridge to [bus 02] pci 0000:02:00.0: no compatible bridge window for [mem 0x3100ffffc000-0x3100ffffffff 64bit pref] Switching to clocksource refined-jiffies pnp: PnP ACPI: disabled pci 0000:00:1c.0: BAR 14: assigned [mem 0x80000000-0x801fffff] pci 0000:00:1c.0: BAR 15: assigned [mem 0x80200000-0x803fffff 64bit pref] pci 0000:00:1c.2: BAR 15: assigned [mem 0x80400000-0x804fffff 64bit pref] pci 0000:00:1c.0: BAR 13: assigned [io 0x1000-0x1fff] pci 0000:00:1c.0: PCI bridge to [bus 01] pci 0000:00:1c.0: bridge window [io 0x1000-0x1fff] pci 0000:00:1c.0: bridge window [mem 0x80000000-0x801fffff] pci 0000:00:1c.0: bridge window [mem 0x80200000-0x803fffff 64bit pref] pci 0000:02:00.0: BAR 4: assigned [mem 0x80400000-0x80403fff 64bit pref] pci 0000:00:1c.2: PCI bridge to [bus 02] pci 0000:00:1c.2: bridge window [io 0x3000-0x3fff] pci 0000:00:1c.2: bridge window [mem 0xd1000000-0xd10fffff] pci 0000:00:1c.2: bridge window [mem 0x80400000-0x804fffff 64bit pref] pci 0000:00:1c.0: can't find IRQ for PCI INT A; please try using pci=biosirq pci 0000:00:1c.2: can't find IRQ for PCI INT C; please try using pci=biosirq NET: Registered protocol family 2 TCP established hash table entries: 16384 (order: 6, 262144 bytes) TCP bind hash table entries: 16384 (order: 6, 262144 bytes) TCP: Hash tables configured (established 16384 bind 16384) TCP: reno registered UDP hash table entries: 1024 (order: 3, 32768 bytes) UDP-Lite hash table entries: 1024 (order: 3, 32768 bytes) NET: Registered protocol family 1 RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. pci 0000:00:1d.0: can't find IRQ for PCI INT A; please try using pci=biosirq Trying to unpack rootfs image as initramfs... rootfs image is not initramfs (no cpio magic); looks like an initrd Freeing initrd memory: 65536k freed platform rtc_cmos: registered platform RTC device (no PNP device found) microcode: CPU0 sig=0x30673, pf=0x1, revision=0x322 microcode: CPU1 sig=0x30673, pf=0x1, revision=0x322 microcode: Microcode Update Driver: v2.00 tigran@aivazian.fsnet.co.uk, Peter Oruba Scanning for low memory corruption every 60 seconds HugeTLB registered 2 MB page size, pre-allocated 0 pages NFS: Registering the id_resolver key type Key type id_resolver registered Key type id_legacy registered aufs 3.10-20130819 msgmni has been set to 3836 async_tx: api initialized (async) Block layer SCSI generic (bsg) driver version 0.4 loaded (major 250) io scheduler noop registered io scheduler deadline registered io scheduler cfq registered (default) pcieport 0000:00:1c.0: device [8086:0f48] has invalid IRQ; check vendor BIOS pcieport 0000:00:1c.2: device [8086:0f4c] has invalid IRQ; check vendor BIOS dw_dmac_pci 0000:00:18.0: can't find IRQ for PCI INT A; please try using pci=biosirq dw_dmac_pci: probe of 0000:00:18.0 failed with error -2 dw_dmac_pci 0000:00:1e.0: can't find IRQ for PCI INT A; please try using pci=biosirq genirq: Flags mismatch irq 0. 00000080 (dw_dmac) vs. 00015a20 (timer) dw_dmac_pci: probe of 0000:00:1e.0 failed with error -16 Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A serial 0000:00:1e.3: can't find IRQ for PCI INT C; please try using pci=biosirq 0000:00:1e.3: ttyS1 at MMIO 0xd110d000 (irq = 0) is a 16550A serial 0000:00:1e.4: can't find IRQ for PCI INT D; please try using pci=biosirq 0000:00:1e.4: ttyS2 at MMIO 0xd110f000 (irq = 0) is a 16550A Linux agpgart interface v0.103 i2c-designware-pci 0000:00:18.2: can't find IRQ for PCI INT D; please try using pci=biosirq genirq: Flags mismatch irq 0. 00000080 (i2c-designware-pci) vs. 00015a20 (timer) i2c-designware-pci 0000:00:18.2: failure requesting irq 0 i2c-designware-pci: probe of 0000:00:18.2 failed with error -16 i2c-designware-pci 0000:00:18.6: can't find IRQ for PCI INT D; please try using pci=biosirq genirq: Flags mismatch irq 0. 00000080 (i2c-designware-pci) vs. 00015a20 (timer) i2c-designware-pci 0000:00:18.6: failure requesting irq 0 i2c-designware-pci: probe of 0000:00:18.6 failed with error -16 i2c-designware-pci 0000:00:18.7: can't find IRQ for PCI INT B; please try using pci=biosirq genirq: Flags mismatch irq 0. 00000080 (i2c-designware-pci) vs. 00015a20 (timer) i2c-designware-pci 0000:00:18.7: failure requesting irq 0 i2c-designware-pci: probe of 0000:00:18.7 failed with error -16 i801_smbus 0000:00:1f.3: can't find IRQ for PCI INT B; please try using pci=biosirq ACPI Exception: AE_BAD_PARAMETER, Thread 2004746240 could not acquire Mutex [0x1] (20130328/utmutex-285) genirq: Flags mismatch irq 0. 00000080 (i801_smbus) vs. 00015a20 (timer) i801_smbus 0000:00:1f.3: Failed to allocate irq 0: -16 i801_smbus: probe of 0000:00:1f.3 failed with error -16 [drm] Initialized drm 1.1.0 20060810 i915 0000:00:02.0: can't find IRQ for PCI INT A; please try using pci=biosirq [drm] Memory usable by graphics device = 2048M [drm] Supports vblank timestamp caching Rev 1 (10.10.2010). [drm] Driver supports precise vblank timestamp query. vgaarb: device changed decodes: PCI:0000:00:02.0,olddecodes=io+mem,decodes=io+mem:owns=io+mem [drm] GMBUS [i915 gmbus vga] timed out, falling back to bit banging on pin 2 i915 0000:00:02.0: No connectors reported connected with modes [drm] Cannot find any crtc or sizes - going 1024x768 fbcon: inteldrmfb (fb0) is primary device Console: switching to colour frame buffer device 128x48 i915 0000:00:02.0: fb0: inteldrmfb frame buffer device i915 0000:00:02.0: registered panic notifier [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0 brd: module loaded loop: module loaded isci: Intel(R) C600 SAS Controller Driver - version 1.1.0 mpt2sas version 14.100.00.00 loaded ahci 0000:00:13.0: can't find IRQ for PCI INT A; please try using pci=biosirq ahci 0000:00:13.0: controller can't do DEVSLP, turning off ahci: SSS flag set, parallel bus scan disabled ahci 0000:00:13.0: AHCI 0001.0300 32 slots 2 ports 3 Gbps 0x3 impl SATA mode ahci 0000:00:13.0: flags: 64bit ncq stag pm led clo pio slum part sxs deso scsi0 : ahci scsi1 : ahci ata1: SATA max UDMA/133 abar m2048@0xd0404000 port 0xd0404100 irq 104 ata2: SATA max UDMA/133 abar m2048@0xd0404000 port 0xd0404180 irq 104 pxa2xx_spi_pci 0000:00:1e.5: can't find IRQ for PCI INT B; please try using pci=biosirq genirq: Flags mismatch irq 0. 00000080 (pxa2xx-spi.0) vs. 00015a20 (timer) pxa2xx-spi pxa2xx-spi.0: cannot get IRQ 0 pxa2xx-spi: probe of pxa2xx-spi.0 failed with error -16 e100: Intel(R) PRO/100 Network Driver, 3.5.24-k2-NAPI e100: Copyright(c) 1999-2006 Intel Corporation e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI e1000: Copyright (c) 1999-2006 Intel Corporation. e1000e: Intel(R) PRO/1000 Network Driver - 2.3.2-k e1000e: Copyright(c) 1999 - 2013 Intel Corporation. igb: Intel(R) Gigabit Ethernet Network Driver - version 5.0.5-k igb: Copyright (c) 2007-2013 Intel Corporation. ixgbe: Intel(R) 10 Gigabit PCI Express Network Driver - version 3.13.10-k ixgbe: Copyright (c) 1999-2013 Intel Corporation. ixgb: Intel(R) PRO/10GbE Network Driver - version 1.0.135-k2-NAPI ixgb: Copyright (c) 1999-2008 Intel Corporation. r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded r8169 0000:02:00.0: can't find IRQ for PCI INT A; please try using pci=biosirq r8169 0000:02:00.0 eth0: RTL8168g/8111g at 0xffffc900003aa000, 00:13:20:fe:35:79, XID 0c000800 IRQ 105 r8169 0000:02:00.0 eth0: jumbo features [frames: 9200 bytes, tx checksumming: ko] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver ehci-pci: EHCI PCI platform driver ehci-pci 0000:00:1d.0: can't find IRQ for PCI INT A; please try using pci=biosirq ehci-pci 0000:00:1d.0: Found HC with no IRQ. Check BIOS/PCI 0000:00:1d.0 setup! ehci-pci 0000:00:1d.0: init 0000:00:1d.0 fail, -19 uhci_hcd: USB Universal Host Controller Interface driver usbcore: registered new interface driver usb-storage usbcore: registered new interface driver usbserial usbcore: registered new interface driver usbserial_generic usbserial: USB Serial support registered for generic i8042: PNP: No PS/2 controller found. Probing ports directly. i8042: No controller found mousedev: PS/2 mouse device common for all mice input: PC Speaker as /devices/platform/pcspkr/input/input0 rtc_cmos rtc_cmos: rtc core: registered rtc_cmos as rtc0 rtc_cmos rtc_cmos: alarms up to one day, 114 bytes nvram md: linear personality registered for level -1 md: raid0 personality registered for level 0 md: raid1 personality registered for level 1 md: raid10 personality registered for level 10 md: raid6 personality registered for level 6 md: raid5 personality registered for level 5 md: raid4 personality registered for level 4 md: multipath personality registered for level -4 md: faulty personality registered for level -5 device-mapper: ioctl: 4.24.0-ioctl (2013-01-15) initialised: dm-devel@redhat.com Intel P-state driver initializing. cpuidle: using governor ladder cpuidle: using governor menu sdhci: Secure Digital Host Controller Interface driver sdhci: Copyright(c) Pierre Ossman sdhci-pci 0000:00:11.0: SDHCI controller found [8086:0f15] (rev c) sdhci-pci 0000:00:11.0: can't find IRQ for PCI INT A; please try using pci=biosirq genirq: Flags mismatch irq 0. 00000080 (mmc0) vs. 00015a20 (timer) mmc0: Failed to request IRQ 0: -16 sdhci-pci: probe of 0000:00:11.0 failed with error -16 sdhci-pci 0000:00:12.0: SDHCI controller found [8086:0f16] (rev c) sdhci-pci 0000:00:12.0: can't find IRQ for PCI INT A; please try using pci=biosirq genirq: Flags mismatch irq 0. 00000080 (mmc0) vs. 00015a20 (timer) mmc0: Failed to request IRQ 0: -16 sdhci-pci: probe of 0000:00:12.0 failed with error -16 sdhci-pltfm: SDHCI platform and OF driver helper usbcore: registered new interface driver usbhid usbhid: USB HID core driver oprofile: using NMI interrupt. u32 classifier Actions configured TCP: cubic registered NET: Registered protocol family 17 Key type dns_resolver registered console [netcon0] enabled netconsole: network logging started rtc_cmos rtc_cmos: setting system clock to 2015-06-18 12:29:47 UTC (1434630587) ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) ata1.00: ATA-8: TOSHIBA MQ01ACF050, AV001D, max UDMA/100 ata1.00: 976773168 sectors, multi 16: LBA48 NCQ (depth 31/32), AA ata1.00: configured for UDMA/100 scsi 0:0:0:0: Direct-Access ATA TOSHIBA MQ01ACF0 AV00 PQ: 0 ANSI: 5 sd 0:0:0:0: [sda] 976773168 512-byte logical blocks: (500 GB/465 GiB) sd 0:0:0:0: [sda] 4096-byte physical blocks sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Switching to clocksource tsc sda: sda1 sda2 sda3 sda4 sd 0:0:0:0: [sda] Attached SCSI disk ata2: SATA link down (SStatus 0 SControl 300) md: Waiting for all devices to be available before autodetect md: If you don't use raid, use raid=noautodetect md: Autodetecting RAID arrays. md: Scanned 0 and added 0 devices. md: autorun ... md: ... autorun DONE. RAMDISK: gzip image found at block 0 VFS: Mounted root (ext2 filesystem) on device 1:0. devtmpfs: mounted Freeing unused kernel memory: 1148k freed Write protecting the kernel read-only data: 12288k Freeing unused kernel memory: 264k freed Freeing unused kernel memory: 896k freed udevd[85]: starting version 182 dwc3-pci 0000:00:16.0: can't find IRQ for PCI INT A; please try using pci=biosirq ACPI Exception: AE_BAD_PARAMETER, Thread 1932870960 could not acquire Mutex [0x1] (20130328/utmutex-285) ACPI Exception: AE_BAD_PARAMETER, Thread 1932870960 could not acquire Mutex [0x1] (20130328/utmutex-285) ACPI Exception: AE_BAD_PARAMETER, Thread 1932870960 could not acquire Mutex [0x1] (20130328/utmutex-285) iTCO_vendor_support: vendor-support=0 iTCO_wdt: Intel TCO WatchDog Timer Driver v1.11 iTCO_wdt: unable to reset NO_REBOOT flag, device disabled by hardware/BIOS