一、修改Makefile配置

首先解壓原始碼包：

tar -jxvf busybox-1.25.0.tar.bz2

進入busybox-1.25.0目錄，修改Makefile檔案如下：

ARCH ?= arm

CROSS_COMPILE ?= arm-linux-

二、修改配置檔案

make menuconfig

選擇Busybox Settings--->Build Options--->，選擇[*] Build Busybox as a static binary（no shared libs）

三、編譯

make

出現如下錯誤：

miscutils/nandwrite.c: In function 'nandwrite_main':
miscutils/nandwrite.c:151: error: 'MTD_FILE_MODE_RAW' undeclared (first use in this function)
miscutils/nandwrite.c:151: error: (Each undeclared identifier is reported only once
miscutils/nandwrite.c:151: error: for each function it appears in.)
scripts/Makefile.build:197: recipe for target 'miscutils/nandwrite.o' failed
make[1]: *** [miscutils/nandwrite.o] Error 1
Makefile:742: recipe for target 'miscutils' failed
make: *** [miscutils] Error 2

解決辦法：

MTD_FILE_MODE_RAW在/usr/include/mtd/mtd-abi.h中定義，直接在nandwrite.c中包含<mtd/mtd-abi.h>編譯仍無法通過。將/usr/include/mtd/mtd-abi.h拷貝到busybox的include檔案中，然後包含該標頭檔案：

#include "libbb.h"
#include "mtd-abi.h"
#include <mtd/mtd-user.h>

編譯可以通過。

繼續make，出現如下錯誤：

util-linux/blkdiscard.c: In function 'blkdiscard_main':
util-linux/blkdiscard.c:72: error: 'BLKSECDISCARD' undeclared (first use in this function)
util-linux/blkdiscard.c:72: error: (Each undeclared identifier is reported only once
util-linux/blkdiscard.c:72: error: for each function it appears in.)
scripts/Makefile.build:197: recipe for target 'util-linux/blkdiscard.o' failed
make[1]: *** [util-linux/blkdiscard.o] Error 1
Makefile:742: recipe for target 'util-linux' failed
make: *** [util-linux] Error 2

解決辦法：

BLKSECDISCARD在/usr/include/linux/fs.h中定義，方法如上所述，將/usr/include/linux/fs.h拷貝到busybox的include檔案中，然後修改blkdiscard.c中標頭檔案包含：

修改：#include <linux/fs.h>為

#include "fs.h"

繼續make，編譯通過，但是在連結的時候出現問題：

networking/lib.a(nslookup.o): In function `print_host':
nslookup.c:(.text.print_host+0x44): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
debianutils/lib.a(mktemp.o): In function `mktemp_main':
mktemp.c:(.text.mktemp_main+0x98): warning: the use of `mktemp' is dangerous, better use `mkstemp'
networking/lib.a(ipcalc.o): In function `ipcalc_main':
ipcalc.c:(.text.ipcalc_main+0x25c): warning: Using 'gethostbyaddr' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
libbb/lib.a(inet_common.o): In function `INET_resolve':
inet_common.c:(.text.INET_resolve+0x60): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
networking/lib.a(inetd.o): In function `reread_config_file':
inetd.c:(.text.reread_config_file+0x230): warning: Using 'getservbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
networking/lib.a(netstat.o): In function `ip_port_str':
netstat.c:(.text.ip_port_str+0x50): warning: Using 'getservbyport' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
util-linux/lib.a(nsenter.o): In function `nsenter_main':
nsenter.c:(.text.nsenter_main+0x1b0): undefined reference to `setns'

collect2: ld returned 1 exit status
Note: if build needs additional libraries, put them in CONFIG_EXTRA_LDLIBS.
Example: CONFIG_EXTRA_LDLIBS="pthread dl tirpc audit pam"
Makefile:717: recipe for target 'busybox_unstripped' failed
make: *** [busybox_unstripped] Error 1 

解決辦法：

make menuconfig

Linux System Utilities--->nsenter，去掉該選項，重新編譯make，又出現如下錯誤：

networking/lib.a(nslookup.o): In function `print_host':
nslookup.c:(.text.print_host+0x44): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
debianutils/lib.a(mktemp.o): In function `mktemp_main':
mktemp.c:(.text.mktemp_main+0x98): warning: the use of `mktemp' is dangerous, better use `mkstemp'
networking/lib.a(ipcalc.o): In function `ipcalc_main':
ipcalc.c:(.text.ipcalc_main+0x25c): warning: Using 'gethostbyaddr' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
libbb/lib.a(inet_common.o): In function `INET_resolve':
inet_common.c:(.text.INET_resolve+0x60): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
networking/lib.a(inetd.o): In function `reread_config_file':
inetd.c:(.text.reread_config_file+0x230): warning: Using 'getservbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
networking/lib.a(netstat.o): In function `ip_port_str':
netstat.c:(.text.ip_port_str+0x50): warning: Using 'getservbyport' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
coreutils/lib.a(sync.o): In function `sync_main':
sync.c:(.text.sync_main+0x7c): undefined reference to `syncfs'
collect2: ld returned 1 exit status
Note: if build needs additional libraries, put them in CONFIG_EXTRA_LDLIBS.
Example: CONFIG_EXTRA_LDLIBS="pthread dl tirpc audit pam"
Makefile:717: recipe for target 'busybox_unstripped' failed
make: *** [busybox_unstripped] Error 1

解決辦法：

make menuconfig

Coreutils--->sync選項去掉，重新make編譯通過，生成了busybox可執行檔案。

具體選項是什麼意思還不太清楚，需要進一步理解。