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制作RAMDISK in KERNEL的NetBSD微系统(转)

原创 Linux操作系统 作者:ilg 时间:2019-04-26 10:39:06 0 删除 编辑
制作RAMDISK in KERNEL的NetBSD微系统(转)

  Matthew(黑夜编码人)

  前言

  在前面我们已经讲过如何制作软盘上运行的FreeBSD和OpenBSD系统,现在我们来看看如何制作一个运行在软盘上的NetBSD系统。同软盘中的OpenBSD系统一样,我们还是将系统中的所有配制文件及程序全部存放到NetBSD的内核中,这样整个系统看起来就是一个文件。下面让我们具体来看看如何完成这样一个微系统的制作。

  0、NetBSD的启动过程

  当硬盘MBR中的引导程序接过启动之后,MBR中的程序将读入硬盘NetBSD分区中的引导程序,引导程序默认情况下会加载/boot,然后由boot载入内核/netbsd,此时内核开始检测一些硬件和做一些初始化。初始化完成后kernel将mount root device,然后启动系统初始化进程/sbin/init,init将根据/etc/rc中的设置来进行初始化等。

  1、定制RAMDISK内核

  要使用RAMDISK in KERNEL就必须在内核配制文件中加入以下选项:

options MEMORY_DISK_HOOKS

options MEMORY_DISK_IS_ROOT # force root on memory disk

options MEMORY_DISK_SERVER=0

options MEMORY_DISK_ROOT_SIZE=10000 # size of memory disk, in blocks

options MEMORY_RBFLAGS=0x00 # boot in to multi-user mode

pseudo-device md 1 # memory disk device (ramdisk)

  以上的内核参数意义如下:

  MEMORY_DISK_ROOT_SIZE : 内存磁盘大小,以块为单位

MEMORY_RBFLAGS=0x00 : 启动到多用户模式

  以下是在我机器上使用的一个内核配制文件

include "arch/i386/conf/std.i386"

  #options INCLUDE_CONFIG_FILE # embed config file in kernel binary

  makeoptions COPTS="-Os" # Optimise for space. Implies -O2

  # Enable the hooks used for initializing the root memory-disk.

options MEMORY_DISK_HOOKS

options MEMORY_DISK_IS_ROOT # force root on memory disk

options MEMORY_DISK_SERVER=1 # 0 readonly 1 writable

options MEMORY_DISK_ROOT_SIZE=10000 # size of memory disk, in blocks

options MEMORY_RBFLAGS=0x00 # boot in to multi-user mode

  maxusers 48 # estimated number of users

  # CPU support. At least one is REQUIRED.

options I386_CPU

options I686_CPU

  # CPU-related options.

options MATH_EMULATE # floating point emulation

  # This option allows you to force a serial console at the specified

# I/O address.

#options CONSDEVNAME=""com"",CONADDR=0x3f8,CONSPEED=9600

  # Avoid irq 5 and 7, the most likely cause of problems on modern laptops.

options PCIC_ISA_INTR_ALLOC_MASK=0xff5f

  # Standard system options

  options INSECURE # disable kernel security levels

  options RTC_OFFSET=0 # hardware clock is this many mins. west of GMT

#options NTP # NTP phase/frequency locked loop

  options USERCONF # userconf(4) support

options PIPE_SOCKETPAIR # smaller, but slower pipe(2)

options MALLOC_NOINLINE # Not inlining MALLOC saves memory

  # File systems

file-system FFS # UFS

file-system MFS # memory file system

file-system MSDOSFS # MS-DOS file system

file-system KERNFS # /kern

  options VNODE_OP_NOINLINE # Not inlining vnode op calls saves mem

  # Networking options

options GATEWAY # packet forwarding

options INET # IP + ICMP + TCP + UDP

#options PFIL_HOOKS # pfil(9) packet filter hooks

  # builtin terminal emulations

options WSEMUL_VT100 # VT100 / VT220 emulation

# different kernel output - see dev/wscons/wsdisplayvar.h

options WS_KERNEL_FG=WSCOL_BLACK

options WS_KERNEL_BG=WSCOL_WHITE

# compatibility to other console drivers

#options WSDISPLAY_COMPAT_PCVT # emulate some ioctls

#options WSDISPLAY_COMPAT_SYSCONS # emulate some ioctls

#options WSDISPLAY_COMPAT_USL # VT handling

#options WSDISPLAY_COMPAT_RAWKBD # can get raw scancodes

# see dev/pckbc/wskbdmap_mfii.c for implemented layouts

#options PCKBD_LAYOUT="(KB_DE | KB_NODEAD)"

# allocate a number of virtual screens at autoconfiguration time

#options WSDISPLAY_DEFAULTSCREENS=4

# use a large software cursor that doesn't blink

options PCDISPLAY_SOFTCURSOR

# modify the screen type of the console; defaults to "80x25"

#options VGA_CONSOLE_SCREENTYPE=""80x24""

  # Kernel root file system and dump configuration.

config netbsd root on ? type ?

#config netbsd root on sd0a type ffs

#config netbsd root on ? type nfs

  #

# Device configuration

#

  mainbus0 at root

  cpu* at mainbus?

  apm0 at mainbus0 # Advanced power management

  

# Basic Bus Support

  # PCI bus support

pci* at mainbus? bus ?

pci* at pchb? bus ?

pci* at ppb? bus ?

  # PCI bridges

pchb* at pci? dev ? function ? # PCI-Host bridges

pceb* at pci? dev ? function ? # PCI-EISA bridges

pcib* at pci? dev ? function ? # PCI-ISA bridges

ppb* at pci? dev ? function ? # PCI-PCI bridges

# XXX 'puc's aren't really bridges, but there's no better place for them here

puc* at pci? dev ? function ? # PCI "universal" comm. cards

  # ISA bus support

isa0 at mainbus?

isa0 at pceb?

isa0 at pcib?

  # ISA Plug-and-Play bus support

isapnp0 at isa?

  # Coprocessor Support

  # Math Coprocessor support

npx0 at isa? port 0xf0 irq 13 # x86 math coprocessor

  

# Console Devices

  # ISA console

#pc0 at isa? port 0x60 irq 1 # pccons generic PC console driver

  # wscons

pckbc0 at isa? # pc keyboard controller

pckbd* at pckbc? # PC keyboard

#pms* at pckbc? # PS/2 mouse for wsmouse

vga0 at isa?

vga* at pci? dev ? function ?

pcdisplay0 at isa? # CGA, MDA, EGA, HGA

wsdisplay* at vga? console ?

wsdisplay* at pcdisplay? console ?

wskbd* at pckbd? console ?

#wsmouse* at pms? mux 0

  pcppi0 at isa?

sysbeep0 at pcppi?

  # Serial Devices

  # PCI serial interfaces

com* at puc? port ? # 16x50s on "universal" comm boards

#cy* at pci? dev ? function ? # Cyclades Cyclom-Y serial boards

  # ISA Plug-and-Play serial interfaces

com* at isapnp? # Modems and serial boards

  # ISA serial interfaces

#options COM_HAYESP # adds Hayes ESP serial board support

com0 at isa? port 0x3f8 irq 4 # Standard PC serial ports

com1 at isa? port 0x2f8 irq 3

com2 at isa? port 0x3e8 irq 5

#com3 at isa? port 0x2e8 irq 9

#ast0 at isa? port 0x1a0 irq 5 # AST 4-port serial cards

#com* at ast? slave ?

#boca0 at isa? port 0x100 irq 5 # BOCA 8-port serial cards

#com* at boca? slave ?

#tcom0 at isa? port 0x100 irq 7 # TC-800 8-port serial cards

#com* at tcom? slave ?

#rtfps0 at isa? port 0x1230 irq 10 # RT 4-port serial cards

#com* at rtfps? slave ?

#cy0 at isa? iomem 0xd4000 irq 12 # Cyclades serial cards

  # Miscellaneous mass storage devices

  # Network Interfaces

  # PCI network interfaces

fxp* at pci? dev ? function ? # Intel EtherExpress PRO 10+/100B

le* at pci? dev ? function ? # PCnet-PCI Ethernet

pcn* at pci? dev ? function ? # AMD PCnet-PCI Ethernet

rtk* at pci? dev ? function ? # Realtek 8129/8139

  amhphy* at mii? phy ? # AMD 79c901 Ethernet PHYs

urlphy* at mii? phy ? # Realtek RTL8150L internal PHYs

ukphy* at mii? phy ? # generic unknown PHYs

  # Pseudo-Devices

  # disk/mass storage pseudo-devices

pseudo-device md 1 # memory disk device (ramdisk)

#pseudo-device vnd 4 # disk-like interface to files

  # network pseudo-devices

pseudo-device bpfilter 8 # Berkeley packet filter

pseudo-device ipfilter # IP filter (firewall) and NAT

pseudo-device loop # network loopback

pseudo-device ppp 2 # Point-to-Point Protocol

pseudo-device pppoe 3

  # miscellaneous pseudo-devices

pseudo-device pty 2 # pseudo-terminals (Sysinst needs two)

# wscons pseudo-devices

pseudo-device wsmux # mouse & keyboard multiplexor

#pseudo-device wsfont

  2、制作ramdisk镜像

# dd if=/dev/zero of=/ramdisk bs=512 count=9000

# vnconfig -c /dev/vnd0d /ramdisk

# disklabel -r -w /dev/vnd0d rdroot

# newfs -m 0 -S 512 -i 4096 /dev/vnd0a

# mount /dev/vnd0a /mnt

# mkdir /mnt/{dev,bin,sbin,etc}

# cp /dev/MAKEDEV /mnt/dev

# cp /bin/{sh,ls} /mnt/bin

# cp /sbin/init /mnt/sbin

# cd /mnt/dev/ && ./MAKEDEV ramdisk

# echo 'echo "This is my minibsd all in kernel" && /bin/sh' > /mnt/etc/rc

# sync && umount /mnt

# sync && vnconfig -u vnd0d && sync

  3、将ramdisk写入kernel

# mdsetroot /minibsd ramdisk

  4、压缩kernel大小

# gzip -9 -c /minibsd > /minibsd.gz

  5、制作目标软盘

  因为系统需要使用/boot(/usr/mdec/boot)来加载kernel,所以我们需要在软盘上放置boot文件。

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