基于arm的fast models的架构仿真和linux kernel 开发

基于arm的fast models，利用仿真方法快速设计linux kernel软件，和arm架构的硬件设计进行并行开发，是现在较为高效的linux kernel软件开发的方法，有点类似航空航天领域和汽车领域的原型仿真设计方法论。

现在，linaro组织会提供这种设计方法的linux kernel code，免费开源，总是很好的。附上采用armv8 模型和，linaro kernel的镜像，openembedded core编译出的filesystem，启动linux系统的log。

jialin@qinghe-server:~$ telnet 127.0.0.1 5000
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 4.1.0-1-linaro-vexpress64 (buildslave@x86-64-07) (gcc version 4.9.2 20140904 (prerelease) (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) ) #1ubuntu1~ci+150619142903 SMP PREEMPT Fri Jun 19 14:29:48 UTC 20
[    0.000000] CPU: AArch64 Processor [410fd000] revision 0
[    0.000000] Detected PIPT I-cache on CPU0
[    0.000000] efi: Getting EFI parameters from FDT:
[    0.000000] efi: UEFI not found.
[    0.000000] cma: Reserved 32 MiB at 0x00000000fe000000
[    0.000000] PERCPU: Embedded 18 pages/cpu @ffffffc87ff8b000 s32832 r8192 d32704 u73728
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 1034240
[    0.000000] Kernel command line: console=ttyAMA0 earlyprintk=pl011,0x1c090000 consolelog=9 rw root=/dev/vda2
[    0.000000] PID hash table entries: 4096 (order: 3, 32768 bytes)
[    0.000000] Dentry cache hash table entries: 524288 (order: 10, 4194304 bytes)
[    0.000000] Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes)
[    0.000000] software IO TLB [mem 0xf9fff000-0xfdfff000] (64MB) mapped at [ffffffc079fff000-ffffffc07dffefff]
[    0.000000] Memory: 4019160K/4194304K available (7765K kernel code, 745K rwdata, 2696K rodata, 644K init, 459K bss, 142376K reserved, 32768K cma-reserved)
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vmalloc : 0xffffff8000000000 - 0xffffffbdffff0000   (   247 GB)
[    0.000000]     vmemmap : 0xffffffbe00000000 - 0xffffffbfc0000000   (     7 GB maximum)
[    0.000000]               0xffffffbe01c00000 - 0xffffffbe1f800000   (   476 MB actual)
[    0.000000]     fixed   : 0xffffffbffabfd000 - 0xffffffbffac00000   (    12 KB)
[    0.000000]     PCI I/O : 0xffffffbffae00000 - 0xffffffbffbe00000   (    16 MB)
[    0.000000]     modules : 0xffffffbffc000000 - 0xffffffc000000000   (    64 MB)
[    0.000000]     memory  : 0xffffffc000000000 - 0xffffffc880000000   ( 34816 MB)
[    0.000000]       .init : 0xffffffc000aba000 - 0xffffffc000b5b000   (   644 KB)
[    0.000000]       .text : 0xffffffc000080000 - 0xffffffc000ab95e4   ( 10470 KB)
[    0.000000]       .data : 0xffffffc000b5f000 - 0xffffffc000c19600   (   746 KB)
[    0.000000] Preemptible hierarchical RCU implementation.
[    0.000000] Additional per-CPU info printed with stalls.
[    0.000000] RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
[    0.000000] NR_IRQS:64 nr_irqs:64 0
[    0.000000] Architected cp15 timer(s) running at 100.00MHz (phys).
[    0.000000] clocksource arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x171024e7e0, max_idle_ns: 440795205315 ns
[    0.000026] sched_clock: 56 bits at 100MHz, resolution 10ns, wraps every 4398046511100ns
[    0.002195] Console: colour dummy device 80x25
[    0.002273] Calibrating delay loop (skipped), value calculated using timer frequency.. 200.00 BogoMIPS (lpj=1000000)
[    0.002329] pid_max: default: 32768 minimum: 301
[    0.002904] Security Framework initialized
[    0.002979] AppArmor: AppArmor initialized
[    0.003263] Mount-cache hash table entries: 8192 (order: 4, 65536 bytes)
[    0.003321] Mountpoint-cache hash table entries: 8192 (order: 4, 65536 bytes)
[    0.006903] ftrace: allocating 27563 entries in 108 pages
[    0.293559] hw perfevents: enabled with arm/armv8-pmuv3 PMU driver, 9 counters available
[    0.293747] EFI services will not be available.
[    1.355497] CPU1: failed to come online
[    2.377872] CPU2: failed to come online
[    3.400247] CPU3: failed to come online
[    3.400398] Brought up 1 CPUs
[    3.400432] SMP: Total of 1 processors activated.
[    3.400465] CPU: All CPU(s) started at EL2
[    3.402158] devtmpfs: initialized
[    3.408393] evm: security.selinux
[    3.408427] evm: security.SMACK64
[    3.408460] evm: security.capability
[    3.409395] DMI not present or invalid.
[    3.411141] clocksource jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    3.420838] xor: measuring software checksum speed
[    3.520595]    8regs     :   167.200 MB/sec
[    3.620838]    8regs_prefetch:   144.000 MB/sec
[    3.721094]    32regs    :   171.600 MB/sec
[    3.821345]    32regs_prefetch:   144.000 MB/sec
[    3.821387] xor: using function: 32regs (171.600 MB/sec)
[    3.826464] ACPI Exception: AE_BAD_PARAMETER, Thread 2073299968 could not acquire Mutex [0x1] (20150410/utmutex-285)
[    3.827372] ACPI Exception: AE_BAD_PARAMETER, Thread 2073299968 could not acquire Mutex [0x1] (20150410/utmutex-285)
[    3.827921] ACPI Exception: AE_BAD_PARAMETER, Thread 2073299968 could not acquire Mutex [0x1] (20150410/utmutex-285)
[    3.828595] ACPI Exception: AE_BAD_PARAMETER, Thread 2073299968 could not acquire Mutex [0x1] (20150410/utmutex-285)
[    3.829156] ACPI Exception: AE_BAD_PARAMETER, Thread 2073299968 could not acquire Mutex [0x1] (20150410/utmutex-285)
[    3.829707] ACPI Exception: AE_BAD_PARAMETER, Thread 2073299968 could not acquire Mutex [0x1] (20150410/utmutex-285)
[    3.830500] ACPI Exception: AE_BAD_PARAMETER, Thread 2073299968 could not acquire Mutex [0x1] (20150410/utmutex-285)
[    3.835287] NET: Registered protocol family 16
[    3.902032] cpuidle: using governor ladder
[    3.961783] cpuidle: using governor menu
[    3.962668] vdso: 2 pages (1 code @ ffffffc000b65000, 1 data @ ffffffc000b64000)
[    3.962830] hw-breakpoint: found 16 breakpoint and 16 watchpoint registers.
[    3.967244] DMA: preallocated 256 KiB pool for atomic allocations
[    3.967352] Serial: AMBA PL011 UART driver
[    3.977407] 1c090000.uart: ttyAMA0 at MMIO 0x1c090000 (irq = 11, base_baud = 0) is a PL011 rev2
[    3.981156] console [ttyAMA0] enabled
[    3.983432] 1c0a0000.uart: ttyAMA1 at MMIO 0x1c0a0000 (irq = 12, base_baud = 0) is a PL011 rev2
[    3.986086] 1c0b0000.uart: ttyAMA2 at MMIO 0x1c0b0000 (irq = 13, base_baud = 0) is a PL011 rev2
[    3.988491] 1c0c0000.uart: ttyAMA3 at MMIO 0x1c0c0000 (irq = 14, base_baud = 0) is a PL011 rev2
[    4.326735] raid6: int64x1  gen()    55 MB/s
[    4.496325] raid6: int64x1  xor()    31 MB/s
[    4.667640] raid6: int64x2  gen()    65 MB/s
[    4.837638] raid6: int64x2  xor()    36 MB/s
[    5.007820] raid6: int64x4  gen()    71 MB/s
[    5.178241] raid6: int64x4  xor()    40 MB/s
[    5.348949] raid6: int64x8  gen()    58 MB/s
[    5.519702] raid6: int64x8  xor()    36 MB/s
[    5.689701] raid6: neonx1   gen()   138 MB/s
[    5.859802] raid6: neonx2   gen()   170 MB/s
[    6.030305] raid6: neonx4   gen()   192 MB/s
[    6.200746] raid6: neonx8   gen()   172 MB/s
[    6.200803] raid6: using algorithm neonx4 gen() 192 MB/s
[    6.200861] raid6: using intx1 recovery algorithm
[    6.201393] ACPI: Interpreter disabled.
[    6.203217] vgaarb: loaded
[    6.205143] SCSI subsystem initialized
[    6.209068] usbcore: registered new interface driver usbfs
[    6.209487] usbcore: registered new interface driver hub
[    6.210104] usbcore: registered new device driver usb
[    6.219354] NetLabel: Initializing
[    6.219404] NetLabel:  domain hash size = 128
[    6.219455] NetLabel:  protocols = UNLABELED CIPSOv4
[    6.219715] NetLabel:  unlabeled traffic allowed by default
[    6.221047] Switched to clocksource arch_sys_counter
[    6.416140] AppArmor: AppArmor Filesystem Enabled
[    6.417113] pnp: PnP ACPI: disabled
[    6.473288] NET: Registered protocol family 2
[    6.476739] TCP established hash table entries: 32768 (order: 6, 262144 bytes)
[    6.480503] TCP bind hash table entries: 32768 (order: 7, 524288 bytes)
[    6.485242] TCP: Hash tables configured (established 32768 bind 32768)
[    6.485393] UDP hash table entries: 2048 (order: 4, 65536 bytes)
[    6.486214] UDP-Lite hash table entries: 2048 (order: 4, 65536 bytes)
[    6.487608] NET: Registered protocol family 1
[    6.488668] RPC: Registered named UNIX socket transport module.
[    6.488729] RPC: Registered udp transport module.
[    6.488784] RPC: Registered tcp transport module.
[    6.488842] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    6.490643] hw perfevents: Failed to parse /pmu/interrupt-affinity[0]
[    6.491625] kvm [1]: interrupt-controller@2c004000 IRQ5
[    6.492292] kvm [1]: timer IRQ3
[    6.492346] kvm [1]: Hyp mode initialized successfully
[    6.497225] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    6.497628] audit: initializing netlink subsys (disabled)
[    6.497738] audit: type=2000 audit(6.360:1): initialized
[    6.505000] HugeTLB registered 2 MB page size, pre-allocated 0 pages
[    6.506326] VFS: Disk quotas dquot_6.6.0
[    6.506630] VFS: Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
[    6.510479] NFS: Registering the id_resolver key type
[    6.510588] Key type id_resolver registered
[    6.510642] Key type id_legacy registered
[    6.511074] jffs2: version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
[    6.512635] 9p: Installing v9fs 9p2000 file system support
[    6.517149] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 252)
[    6.517254] io scheduler noop registered
[    6.517347] io scheduler deadline registered
[    6.517592] io scheduler cfq registered (default)
[    6.520463] pci_hotplug: PCI Hot Plug PCI Core version: 0.5
[    6.523602] pciehp: PCI Express Hot Plug Controller Driver version: 0.4
[    6.880007] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[    6.888795] [drm] Initialized drm 1.1.0 20060810
[    6.932289] brd: module loaded
[    6.955090] loop: module loaded
[    6.958774]  vda: vda1 vda2
[    6.964693] mtdoops: mtd device (mtddev=name/number) must be supplied
[    6.964999] tun: Universal TUN/TAP device driver, 1.6
[    6.965057] tun: (C) 1999-2004 Max Krasnyansky <[e-mail]>
[    6.966321] sky2: driver version 1.30
[    6.967309] smc91x 1a000000.ethernet (unnamed net_device) (uninitialized): smc91x: IOADDR ffffff8000160000 doesn't match configuration (300).
[    6.967399] smc91x.c: v1.1, sep 22 2004 by Nicolas Pitre <[e-mail]>
[    6.979062] smc91x 1a000000.ethernet eth0: SMC91C11xFD (rev 1) at ffffff8000160000 IRQ 10
[    6.979128] 
[    6.979201] smc91x 1a000000.ethernet eth0: Ethernet addr: 00:02:f7:ef:30:ac
[    6.979994] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    6.980100] ehci-pci: EHCI PCI platform driver
[    6.980798] ehci-platform: EHCI generic platform driver
[    6.982749] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[    6.982872] ohci-pci: OHCI PCI platform driver
[    6.983675] usbcore: registered new interface driver usb-storage
[    6.985632] mousedev: PS/2 mouse device common for all mice
[    6.989932] device-mapper: ioctl: 4.31.0-ioctl (2015-3-12) initialised: [e-mail]
[    6.994073] usbcore: registered new interface driver usbhid
[    6.994128] usbhid: USB HID core driver
[    6.996656] Initializing XFRM netlink socket
[    6.996800] NET: Registered protocol family 17
[    6.996944] NET: Registered protocol family 15
[    6.997357] 9pnet: Installing 9P2000 support
[    6.998301] Key type dns_resolver registered
[    7.006550] Btrfs loaded
[    7.010000] Key type encrypted registered
[    7.010093] AppArmor: AppArmor sha1 policy hashing enabled
[    7.010180] ima: No TPM chip found, activating TPM-bypass!
[    7.010519] evm: HMAC attrs: 0x1
[    7.012757] hctosys: unable to open rtc device (rtc0)
[    7.015432] EXT3-fs (vda2): error: couldn't mount because of unsupported optional features (240)
[    7.015853] EXT2-fs (vda2): error: couldn't mount because of unsupported optional features (244)
[    7.052438] EXT4-fs (vda2): recovery complete
[    7.052697] EXT4-fs (vda2): mounted filesystem with ordered data mode. Opts: (null)
[    7.052805] VFS: Mounted root (ext4 filesystem) on device 254:2.
[    7.052989] devtmpfs: mounted
[    7.053878] Freeing unused kernel memory: 644K (ffffffc000aba000 - ffffffc000b5b000)
[    7.053967] Freeing alternatives memory: 8K (ffffffc000b5b000 - ffffffc000b5d000)
INIT: version 2.88 booting
Mounting local filesystems...
Starting udev
cmp: EOF on /etc/udev/cache.data
udev: Not using udev cache because of changes detected in the following files:
udev:     /proc/version /proc/cmdline /proc/devices
udev:     lib/udev/rules.d/* etc/udev/rules.d/*
udev: The udev cache will be regenerated. To identify the detected changes,
udev: compare the cached sysconf at   /etc/udev/cache.data
udev: against the current sysconf at  /dev/shm/udev.cache
[    7.599151] udevd[1125]: starting version 182
Activating swap
[   10.680439] EXT4-fs (vda2): re-mounted. Opts: data=ordered
Starting Bootlog daemon: bootlogd.
Initializing random number generator...
[   10.918325] random: dd urandom read with 11 bits of entropy available
udev-cache: checking for /dev/shm/udev-regen... found.
Populating dev cache
Populating volatile Filesystems.


net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.all.rp_filter = 1
System time was Thu Jan  1 00:00:12 UTC 1970.
Setting the System Clock using the Hardware Clock as reference...
hwclock: can't open '/dev/misc/rtc': No such file or directory
System Clock set. System local time is now Thu Jan  1 00:00:12 UTC 1970.
Thu Jun 18 11:03:04 UTC 2015
Saving the System Clock time to the Hardware Clock...
hwclock: can't open '/dev/misc/rtc': No such file or directory
Hardware Clock updated to Thu Jun 18 11:03:04 UTC 2015.
INIT: Entering runlevel: 5
Configuring network interfaces... [   13.802306] smc91x 1a000000.ethernet eth0: link up, 10Mbps, half-duplex, lpa 0x0000
udhcpc (v1.23.2) started
Sending discover...
Sending select for 172.20.51.1...
Lease of 172.20.51.1 obtained, lease time 86400
/etc/udhcpc.d/50default: Adding DNS 172.20.51.254
/etc/udhcpc.d/50default: Adding DNS 172.20.51.252
/etc/udhcpc.d/50default: Adding DNS 172.20.51.251
done.
Starting OpenBSD Secure Shell server: sshd
  generating ssh DSA key...
  generating ssh ED25519 key...
[   23.494643] NET: Registered protocol family 10
key_load_public: invalid format
Could not load host key: /etc/ssh/ssh_host_rsa_key
key_load_public: invalid format
Could not load host key: /etc/ssh/ssh_host_ecdsa_key
done.
Starting rpcbind daemon...done.
starting statd: done
System time was Thu Jun 18 11:03:14 UTC 2015.
Setting the System Clock using the Hardware Clock as reference...
hwclock: can't open '/dev/misc/rtc': No such file or directory
System Clock set. System local time is now Thu Jun 18 11:03:14 UTC 2015.
NFS daemon support not enabled in kernel
Starting syslogd/klogd: done
Starting auto-serial-console: done
Stopping Bootlog daemon: bootlogd.


INIT: no more processes left in this runlevel
Last login: Thu Jun 18 11:03:15 UTC 2015 on tty1
root@genericarmv8:~# 
root@genericarmv8:~# 
root@genericarmv8:~# ls
hello.c   hello.cc
root@genericarmv8:~# 

总结，这种研究方法总是很好的。除了arm提供这种cpu 的ip核模型外，还有新思科技等提供的ip核模型，例如designware 的usb3.0的ip核。如果这底层能够屏蔽掉ip核模型的硬件设计，在kernel层开发driver，在上层或者android提前开发hal code，将是不错的硬件验证，和软件提前开发，效率较高，还能较早的进行更上层的软件架构设计。