make  ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- -j64 menuconfig

 CROSS_COMPILE=riscv64-linux-gnu- -j64  
 CROSS_COMPILE=riscv64-linux-gnu- -j64  install





root@ubuntu:/home/ubuntu/busybox-1.32.1# find ./ -name tcpdump
root@ubuntu:/home/ubuntu/busybox-1.32.1# cd _install/
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ls
bin  linuxrc  sbin  usr
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# mkdir bin dev tmp proc sys 
mkdir: cannot create directory ‘bin’: File exists
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ls
bin  dev  linuxrc  proc  sbin  sys  tmp  usr
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# 


root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ls
bin  linuxrc  sbin  usr ---------文件系统简单，后续上新功能一大堆问题，
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# mkdir bin dev tmp proc sys 
mkdir: cannot create directory ‘bin’: File exists
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ls
bin  dev  linuxrc  proc  sbin  sys  tmp  usr
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ln -s ../bin/busybox sbin/init
ln: failed to create symbolic link 'sbin/init': File exists
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ln -s bin/busybox linuxrc 
ln: failed to create symbolic link 'linuxrc': File exists
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ln -s sbin/init init  
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install#

root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install# mknod dev/console c 5 1
root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install# mknod dev/ram b 1 0

                      
mkdir bin dev tmp proc sys              # 创建一些系统目录
cp inittab $RISCV/rootfs/etc/inittab    # 拷贝进inittab 文档(可选，可以不拷贝)
ln -s ../bin/busybox sbin/init          # 设定init起始文档连接到busybox
ln -s bin/busybox linuxrc               #
ln -s sbin/init init                    # 
mknod dev/console c 5 1                 # 设置一些必要的虚拟外设()
mknod dev/null c 1 3   
 
/home/ubuntu/busybox-1.32.1# find . -print0 | cpio --null -ov --format=newc | gzip -9 > ../initrams.my.gz

qemu-system-riscv64 -nographic -machine virt  -bios fw_jump.elf -m 1024    \
     -kernel ~/riscv_debug/linux-5.14/arch/riscv/boot/Image  -append "root=/dev/vda ro console=ttyS0,115200n8  earlycon" \
     -initrd initrams.my.gz  

 参考

https://blog.csdn.net/ALLap97/article/details/114300337

交叉编译ethtool

root@ubuntu:/home/ubuntu# git clone git://git.kernel.org/pub/scm/network/ethtool/ethtool.git
Cloning into 'ethtool'...
remote: Enumerating objects: 37, done.
remote: Counting objects: 100% (37/37), done.
remote: Compressing objects: 100% (37/37), done.
remote: Total 3129 (delta 21), reused 0 (delta 0), pack-reused 3092
Receiving objects: 100% (3129/3129), 1.29 MiB | 2.66 MiB/s, done.
Resolving deltas: 100% (2171/2171), done.
root@ubuntu:/home/ubuntu# riscv64-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=riscv64-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/riscv64-linux-gnu/7/lto-wrapper
Target: riscv64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.5.0-3ubuntu1~18.04' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,c++,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --enable-shared --enable-linker-build-id 
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix -
-libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug 
--enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object
 --disable-libitm --disable-libsanitizer --disable-libquadmath --disable-libquadmath-support --enable-plugin --with-system-zlib --enable-multiarch --disable-werror --disable-multilib --with-arch=rv64imafdc --with-abi=lp64d --enable-checking=release --build=aarch64-linux-gnu --host=aarch64-linux-gnu 
--target=riscv64-linux-gnu 
--program-prefix=riscv64-linux-gnu- --includedir=/usr/riscv64-linux-gnu/include
Thread model: posix
gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04) 

-host:代码所在机器

root@ubuntu:/home/ubuntu/ethtool# ./configure  --host=aarch64-linux-gnu  CC=riscv64-linux-gnu-gcc  LDFLAGS=-static 

configure: error: Package requirements (libmnl) were not met:

No package 'libmnl' found

Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively, you may set the environment variables MNL_CFLAGS
and MNL_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
root@ubuntu:/home/ubuntu/ethtool# 

参考编译  debian 交叉编译 ethtool

交叉编译tcpdump 

pcap和tcpdump的prefix要一致

--prefix=/home/ubuntu/rams3/install

ubuntu@ubuntu:~/ rams3$  mkdir /home/ubuntu/ rams3/install
ubuntu@ubuntu:~/ rams3$ export CC=riscv64-linux-gnu-gcc
ubuntu@ubuntu:~/ rams3$ cd libpcap/
ubuntu@ubuntu:~/ rams3/libpcap$  ./configure --prefix=/home/ubuntu/rams3/install --host=riscv64-linux --with-pcap=linux
ubuntu@ubuntu:~/ rams3/libpcap$ make -j 64  
ubuntu@ubuntu:~/ rams3/libpcap$ make -j 64 install
ubuntu@ubuntu:~/ rams3/tcpdump$ ./configure --prefix=/home/ubuntu/rams3/install --host=riscv64-linux

ubuntu@ubuntu:~/ rams3/tcpdump$ make -j64
  
ubuntu@ubuntu:~/ rams3/tcpdump$ find ./ -name tcpdump
./tcpdump
ubuntu@ubuntu:~/ rams3/tcpdump$ file tcpdump
tcpdump: ELF 64-bit LSB shared object, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-, for GNU/Linux 4.15.0, BuildID[sha1]=b2d3378702e876cedc1bc339bb1b3ef13fc4dd3a, with debug_info, not stripped
ubuntu@ubuntu:~/ rams3/tcpdump$ 

将tcpdump拷贝到

root@ubuntu:/home/ubuntu/ busybox-1.32.1# find ./ -name tcpdump
./_install/usr/sbin/tcpdump
root@ubuntu:/home/ubuntu/ busybox-1.32.1# find ./ -name ethool
root@ubuntu:/home/ubuntu/ busybox-1.32.1# find ./ -name ethtool
./_install/usr/sbin/ethtool
root@ubuntu:/home/ubuntu/ busybox-1.32.1# 

 ethool

root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install/usr/lib# ln -s libmnl.so.0.2.0  libmnl.so.0
 
drwxr-xr-x 5 root root  4096 Dec  3 17:52 ..
lrwxrwxrwx 1 root root    15 Dec  3 17:53 libmnl.so.0 -> libmnl.so.0.2.0
-rw-r--r-- 1 root root 14248 Dec  3 16:36 libmnl.so.0.2.0
root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install/usr/lib# 

 tcpdump: socket: Address family not supported by protocol

The remedy
If necessary, update your module dependencies and then load the module manually:

root@linux# depmod -a
root@linux# modprobe af_packet
If required, check whether the module is present:

root@linux# find /lib/modules -name "af_packet*"
/lib/modules/2.6.13-15-default/kernel/net/packet/af_packet.ko
If modprobe does not work, you can try to load the module directly with insmod:

root@linux# insmod /lib/modules/2.6.13-15-default/kernel/net/packet/af_packet.ko

can't open /dev/tty3: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
can't open /dev/tty3: No such file or directory

/ # 
can't open /dev/tty4: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory
f

简单解决办法

不断弹出这样的报错信息

can't open /dev/tty3: No such file or directory
can't open /dev/tty2: No such file or directory
can't open /dev/tty4: No such file or directory

查阅资料后，参考这个博客

输入

ln -sf /dev/null /dev/tty2
ln -sf /dev/null /dev/tty3
ln -sf /dev/null /dev/tty4

就可以正常使用了

复杂解决办法

原来是没有这几个文件

root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install# cat etc/init.d/rcS
cat: etc/init.d/rcS: No such file or directory
root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install# cat etc/fstab
cat: etc/fstab: No such file or directory
root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install# etc/inittab
bash: etc/inittab: No such file or directory
root@ubuntu:/home/ubuntu/ busybox-1.32.1/_install# 

 用buildroot构建的rootfs有

正常的有

[root@centos7 rams]# cat etc/init.d/rcS
#!/bin/sh


# Start all init scripts in /etc/init.d
# executing them in numerical order.
#
for i in /etc/init.d/S??* ;do

     # Ignore dangling symlinks (if any).
     [ ! -f "$i" ] && continue

     case "$i" in
        *.sh)
            # Source shell script for speed.
            (
                trap - INT QUIT TSTP
                set start
                . $i
            )
            ;;
        *)
            # No sh extension, so fork subprocess.
            $i start
            ;;
    esac
done

[root@centos7 rams]# cat etc/fstab
#                   
/dev/root       /               ext2    rw,noauto       0       1
proc            /proc           proc    defaults        0       0
devpts          /dev/pts        devpts  defaults,gid=5,mode=620,ptmxmode=0666   0       0
tmpfs           /dev/shm        tmpfs   mode=0777       0       0
tmpfs           /tmp            tmpfs   mode=1777       0       0
tmpfs           /run            tmpfs   mode=0755,nosuid,nodev  0       0
sysfs           /sys            sysfs   defaults        0       0
[root@centos7 rams]# cat etc/inittab
# /etc/inittab
#
# Copyright (C) 2001 Erik Andersen 
#
# Note: BusyBox init doesn't support runlevels.  The runlevels field is
# completely ignored by BusyBox init. If you want runlevels, use
# sysvinit.
#
# Format for each entry: :::
#
# id        == tty to run on, or empty for /dev/console
# runlevels == ignored
# action    == one of sysinit, respawn, askfirst, wait, and once
# process   == program to run

# Startup the system
::sysinit:/bin/mount -t proc proc /proc
::sysinit:/bin/mount -o remount,rw /
::sysinit:/bin/mkdir -p /dev/pts /dev/shm
::sysinit:/bin/mount -a
::sysinit:/sbin/swapon -a
null::sysinit:/bin/ln -sf /proc/self/fd /dev/fd
null::sysinit:/bin/ln -sf /proc/self/fd/0 /dev/stdin
null::sysinit:/bin/ln -sf /proc/self/fd/1 /dev/stdout
null::sysinit:/bin/ln -sf /proc/self/fd/2 /dev/stderr
::sysinit:/bin/hostname -F /etc/hostname
# now run any rc scripts
::sysinit:/etc/init.d/rcS

# Put a getty on the serial port
console::respawn:/sbin/getty -L  console 0 vt100 # GENERIC_SERIAL

# Stuff to do for the 3-finger salute
#::ctrlaltdel:/sbin/reboot

# Stuff to do before rebooting
::shutdown:/etc/init.d/rcK
::shutdown:/sbin/swapoff -a
::shutdown:/bin/umount -a -r

 添加etc目录之后

modprobe: can't change directory to '/lib/modules': No such file or directory
Initializing random number generator... [    8.710573] random: dd: uninitialized urandom read (512 bytes read)
Jan  1 00:00:08 buildroot user.notice kernel: [    8.710573] random: dd: uninitialized urandom read (512 bytes read)
done.
Starting network: ifup: can't open '/var/run/ifstate.new': No such file or directory
FAIL
Starting dropbear sshd: start-stop-daemon: can't execute '/usr/sbin/dropbear': No such file or directory
FAIL
Jan  1 00:00:08 buildroot daemon.info nit: starting pid 83, tty '/dev/console': '/sbin/getty -L  console 0 vt100 '

Welcome to Buildroot
buildroot login: root
Password: 
Jan  1 00:03:41 buildroot auth.info login[83]: root login on 'console'
# ip a
1: lo:  mtu 65536 qdisc noqueue qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: sit0@NONE:  mtu 1480 qdisc noop qlen 1000
    link/sit 0.0.0.0 brd 0.0.0.0
# ethtool
-sh: ethtool: not found
# cd /
# ls
bin      etc      linuxrc  proc     run      sys      usr
dev      init     net.sh   root     sbin     tmp
# ls etc/
fstab          inittab        nsswitch.conf  protocols      shells
group          issue          os-release     random-seed
hostname       mdev.conf      passwd         screenrc
hosts          mke2fs.conf    profile        services
init.d         network        profile.d      shadow
# ls usr/sbin/ethtool 
usr/sbin/ethtool
# 

-sh: /usr/sbin/tcpdump: not found

modprobe: can't change directory to '/lib/modules': No such file or directory
Initializing random number generator... [    8.711048] random: dd: uninitialized urandom read (512 bytes read)
Jan  1 00:00:08 buildroot user.notice kernel: [    8.711048] random: dd: uninitialized urandom read (512 bytes read)
done.
Starting network: ifup: can't open '/var/run/ifstate.new': No such file or directory
FAIL
Starting dropbear sshd: start-stop-daemon: can't execute '/usr/sbin/dropbear': No such file or directory
FAIL
Jan  1 00:00:08 buildroot daemon.info nit: starting pid 83, tty '/dev/console': '/sbin/getty -L  console 0 vt100 '

Welcome to Buildroot
buildroot login: root
Password: 
Jan  1 00:00:14 buildroot auth.info login[83]: root login on 'console'
# ip a
1: lo:  mtu 65536 qdisc noqueue qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: sit0@NONE:  mtu 1480 qdisc noop qlen 1000
    link/sit 0.0.0.0 brd 0.0.0.0
# tcpdump -h
-sh: tcpdump: not found
# find ./ -name tcpdump
# ls /usr/sbin/tcpdump 
/usr/sbin/tcpdump
# /usr/sbin/tcpdump 
-sh: /usr/sbin/tcpdump: not found
# ls -al /usr/sbin/tcpdump
-rwxr-xr-x    1 root     root       7156824 Dec  3  2021 /usr/sbin/tcpdump
# /usr/sbin/tcpdump -h
-sh: /usr/sbin/tcpdump: not found
# 

 原来是busybox中没有这个命令

root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# ls usr/sbin/
addgroup   chroot      ethtool     i2cdetect    killall5    nologin     readahead     svlogd     ubirename
add-shell  crond       fakeidentd  i2cdump      loadfont    ntpd        readprofile   tcpdump    ubirmvol
adduser    delgroup    fbset       i2cget       lpd         partprobe   remove-shell  telnetd    ubirsvol
arping     deluser     fdformat    i2cset       mim         popmaildir  rtcwake       tftpd      ubiupdatevol
brctl      dhcprelay   fsfreeze    i2ctransfer  nanddump    powertop    sendmail      ubiattach  udhcpd
chat       dnsd        ftpd        ifplugd      nandwrite   rdate       setfont       ubidetach
chpasswd   ether-wake  httpd       inetd        nbd-client  rdev        setlogcons    ubimkvol


root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# grep chpasswd -rn *
Binary file bin/busybox matches
Binary file init matches
Binary file linuxrc matches
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# grep httpd -rn *
Binary file bin/busybox matches
Binary file init matches
Binary file linuxrc matches
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# grep tcpdump -rn *
Binary file usr/sbin/tcpdump matches
root@ubuntu:/home/ubuntu/busybox-1.32.1/_install# 

最终方法

1、找个成熟的initrams

2、交叉编译tcpdump 、ethtool

3、更新initrams

 方法二

debootstraps构造的rootfs

root@ubuntu:/home/ubuntu/data2# find ./ -name libm.so.6
./usr/lib/riscv64-linux-gnu/libm.so.6
root@ubuntu:/home/ubuntu/data2# find ./ -name libresolv.so.2
./usr/lib/riscv64-linux-gnu/libresolv.so.2
root@ubuntu:/home/ubuntu/data2# find ./ -name  libc.so.6
./usr/lib/riscv64-linux-gnu/libc.so.6
root@ubuntu:/home/ubuntu/data2# find ./ -name  ld-linux-riscv64-lp64d.so.1
./usr/lib/riscv64-linux-gnu/ld-linux-riscv64-lp64d.so.1
./usr/lib/ld-linux-riscv64-lp64d.so.1
root@ubuntu:/home/ubuntu/data2# 

先用 debootstrap构造rootfs


 


make ARCH=riscv  CROSS_COMPILE=riscv64-linux-gnu- -j64

Static linking against glibc, can't use --gc-sections
Trying libraries: crypt m resolv rt
 Library crypt is not needed, excluding it
 Library m is needed, can't exclude it (yet)
 Library resolv is needed, can't exclude it (yet)
 Library rt is not needed, excluding it
 Library m is needed, can't exclude it (yet)
 Library resolv is needed, can't exclude it (yet)
Final link with: m resolv

 有这些报错也会生成busybox

root@ubuntu:/home/ubuntu/busybox-1.32.1# ls rootfs/lib64
ld-uClibc-1.0.39.so  ld-uClibc.so.1  libatomic.so.1      libc.so.0  libgcc_s.so    libuClibc-1.0.39.so
ld-uClibc.so.0       libatomic.so    libatomic.so.1.2.0  libc.so.1  libgcc_s.so.1
root@ubuntu:/home/ubuntu/busybox-1.32.1# 
查看busybox依赖的so
root@ubuntu:/home/ubuntu/busybox-1.32.1# ls busybox -al
-rwxr-xr-x 1 root root 1038120 Dec  4 18:42 busybox
root@ubuntu:/home/ubuntu/busybox-1.32.1# readelf -d busybox | grep NEEDED
 0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [libresolv.so.2]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x0000000000000001 (NEEDED)             Shared library: [ld-linux-riscv64-lp64d.so.1]

构建内存 OS (基于 Ubuntu rootfs 和busybox)

http://linuxcoming.com/blog/2019/06/21/build_ram_os.html

Spike 运行RISC-V Linux

版本busybox扩充命令及函数集讲解||扩充applet命令比如tcpdump