概述
其它关于 hostapd udhcpd 的热点配置，网上有很多资料，基本上一搜都能搜到，但是还是记录一下自己操作的过程，有时候有些问题可能不是网上讲到的吧。
准备
也就是确定一下，你的硬件是支持的，有 wifi 芯片的。
配置
hostapd 的配置文件，这个在文尾放一个我的配置吧，udhcpd 也是一样文尾放一个我的配置，这里简单说点。
主要配置也就是配置使用哪个接口，一般就是 wlan0，对应的系统，可能会不一样，反正找对就行，如果没有，尝试 ifconfig wlan0 up 启动，如果启动不了可能就是真的没有，可者驱动等底层有问题吧。
然后在 hostapd 中主要就是配置加密方式，ssid，其它的配置项，可以根据需要再搜索，找官司方档等。
udhcpd 在嵌入式中一般都是来源于 busybox，编译时在busybox 中找到它，同样配置文件就是配置接口，然后再说置可分配的网段，一般源码中给的默认配置用来改改就可以了。
操作过程
- 系统启动，
ifconfig wlan0 up开启 -
ifconfig wlan0 192.168.xx.1设置地址，这个地址应该跟 udhcpd.conf 中配置的的网段是一样，同时其中的router也就是网关部分应该是一样的 -
hostapd xxx/hostapd.conf启动热点 -
udhcpd xxx/udhcpd.conf启动地址分配程序 - 基本这样就可以了，下面就可以用手机连接了
其它问题
- 记得在使能的时候先
ifconfig wlan0 down再ifconfig wlan0 up如果之前系统连接了其它的地方已经分配了地址，再去启动热点，又没有给 wlan0 重新设置成网关地址就会有问题
附件
hostapd.conf
interface=wlan0
ssid=jmdvirus-hostapd
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0
# channel 1-14 is 2.4 GHz ; channel 36, 40, 44, 46, 48, 52, 56, 60,
# 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 149,
# 153, 157, 161 is 5GHz
# The channels that are available for use in a particular country differ
# according to the regulations of that country.
channel=7
# Operation mode (a = IEEE 802.11a, b = IEEE 802.11b, g = IEEE
# 802.11g, Default: IEEE 802.11b )
hw_mode=g
#If the wireless interface is included in a bridge,
#an additional configuration parameter, bridge, is needed
#bridge=br0
# This field is a bit field that can be used to enable WPA
# (IEEE 802.11i/D3.0)
# and/orWPA2 (full IEEE 802.11i/RSN):
# bit1 = IEEE 802.11i/RSN (WPA2) (dot11RSNAEnabled)
#wpa=2
#wpa_passphrase=12345678
# Set of accepted key management algorithms
# (WPA-PSK, WPA-EAP, or both).
#wpa_key_mgmt=WPA-PSK
# Set of accepted cipher suites (encryption algorithms)
# for pairwise keys
#wpa_pairwise=CCMP TKIP
# ieee80211n: Whether IEEE 802.11n (HT) is enabled
# 0 = disabled (default)
# 1 = enabled
ieee80211n=1
# ht_capab: HT capabilities (list of flags)
# Supported channel width set: [HT40-] = both 20 MHz and 40 MHz
# with secondary channel below the primary channel;
# [HT40+] = both 20 MHz and 40 MHz with secondary channel upon
# the primary channel
# Note:There are limits on which channels can be used with HT40- and
# HT40+.Following table shows the channels that may be available for
# HT40- and HT40+ use per IEEE 802.11n Annex J:
# freq HT40- HT40+
# 2.4 GHz 5-13 1-7 (1-9 in Europe/Japan)
# 5 GHz 40,48,56,64 36,44,52,60
# Short GI for 20 MHz: [SHORT-GI-20] (disabled if not set)
# Short GI for 40 MHz: [SHORT-GI-40] (disabled if not set)
#ht_capab=[SHORT-GI-20][SHORT-GI-40]
udhcpd.conf
# Sample udhcpd configuration file (/etc/udhcpd.conf)
# Values shown are defaults
# The start and end of the IP lease block
start 192.168.188.2
end 192.168.188.20
# The interface that udhcpd will use
interface wlan0
# The maximum number of leases (includes addresses reserved
# by OFFER's, DECLINE's, and ARP conflicts). Will be corrected
# if it's bigger than IP lease block, but it ok to make it
# smaller than lease block.
max_leases 16
# The time period at which udhcpd will write out a dhcpd.leases
# file. If this is 0, udhcpd will never automatically write a
# lease file. Specified in seconds.
#auto_time 7200
# The amount of time that an IP will be reserved (leased to nobody)
# if a DHCP decline message is received (seconds)
#decline_time 3600
# The amount of time that an IP will be reserved
# if an ARP conflict occurs (seconds)
#conflict_time 3600
# How long an offered address is reserved (seconds)
offer_time 20
# If client asks for lease below this value, it will be rounded up
# to this value (seconds)
#min_lease 60
# The location of the leases file
lease_file /tmp/conf/udhcpd.leases
# The location of the pid file
pidfile /tmp/udhcpd.pid
# Every time udhcpd writes a leases file, the below script will be called
#notify_file # default: no script
#notify_file dumpleases # useful for debugging
# The following are bootp specific options
# next server to use in bootstrap
#siaddr 192.168.10.22 # default: 0.0.0.0 (none)
# tftp server name
#sname zorak # default: none
# tftp file to download (e.g. kernel image)
#boot_file /var/nfs_root # default: none
# Static leases map
#static_lease 00:60:08:11:CE:4E 192.168.10.54
#static_lease 00:60:08:11:CE:3E 192.168.10.44
# The remainder of options are DHCP options and can be specified with the
# keyword 'opt' or 'option'. If an option can take multiple items, such
# as the dns option, they can be listed on the same line, or multiple
# lines.
# Examples:
opt dns 8.8.8.8
option subnet 255.255.255.0
opt router 192.168.188.1
#opt wins 192.168.188.10
option dns 114.114.114.114 # appended to above DNS servers for a total of 3
#option domain local
#option lease 864000 # default: 10 days
# Arbitrary option in hex form:
#option 0x08 01020304 # option 8: "cookie server IP addr: 1.2.3.4"
# Currently supported options (for more info, see options.c):
#opt lease NUM
#opt subnet IP
#opt broadcast IP
#opt router IP_LIST
#opt ipttl NUM
#opt mtu NUM
#opt hostname STRING # client's hostname
#opt domain STRING # client's domain suffix
#opt search STRING_LIST # search domains
#opt nisdomain STRING
#opt timezone NUM # (localtime - UTC_time) in seconds. signed
#opt tftp STRING # tftp server name
#opt bootfile STRING # tftp file to download (e.g. kernel image)
#opt bootsize NUM # size of that file
#opt rootpath STRING # (NFS) path to mount as root fs
#opt wpad STRING
#opt serverid IP # default: server's IP
#opt message STRING # error message (udhcpd sends it on success too)
# Options specifying server(s)
#opt dns IP_LIST
#opt wins IP_LIST
#opt nissrv IP_LIST
#opt ntpsrv IP_LIST
#opt lprsrv IP_LIST
#opt swapsrv IP
# Obsolete options, no longer supported
#opt logsrv IP_LIST # 704/UDP log server (not syslog!)
#opt namesrv IP_LIST # IEN 116 name server, obsolete (August 1979!!!)
#opt cookiesrv IP_LIST # RFC 865 "quote of the day" server, rarely (never?) used
#opt timesrv IP_LIST # RFC 868 time server, rarely (never?) used