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1===============================================
2Mounting the root filesystem via NFS (nfsroot)
3===============================================
4
5:Authors:
6 Written 1996 by Gero Kuhlmann <gero@gkminix.han.de>
7
8 Updated 1997 by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
9
10 Updated 2006 by Nico Schottelius <nico-kernel-nfsroot@schottelius.org>
11
12 Updated 2006 by Horms <horms@verge.net.au>
13
14 Updated 2018 by Chris Novakovic <chris@chrisn.me.uk>
15
16
17
18In order to use a diskless system, such as an X-terminal or printer server for
19example, it is necessary for the root filesystem to be present on a non-disk
20device. This may be an initramfs (see
21Documentation/filesystems/ramfs-rootfs-initramfs.rst), a ramdisk (see
22Documentation/admin-guide/initrd.rst) or a filesystem mounted via NFS. The
23following text describes on how to use NFS for the root filesystem. For the rest
24of this text 'client' means the diskless system, and 'server' means the NFS
25server.
26
27
28
29
30Enabling nfsroot capabilities
31=============================
32
33In order to use nfsroot, NFS client support needs to be selected as
34built-in during configuration. Once this has been selected, the nfsroot
35option will become available, which should also be selected.
36
37In the networking options, kernel level autoconfiguration can be selected,
38along with the types of autoconfiguration to support. Selecting all of
39DHCP, BOOTP and RARP is safe.
40
41
42
43
44Kernel command line
45===================
46
47When the kernel has been loaded by a boot loader (see below) it needs to be
48told what root fs device to use. And in the case of nfsroot, where to find
49both the server and the name of the directory on the server to mount as root.
50This can be established using the following kernel command line parameters:
51
52
53root=/dev/nfs
54 This is necessary to enable the pseudo-NFS-device. Note that it's not a
55 real device but just a synonym to tell the kernel to use NFS instead of
56 a real device.
57
58
59nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>]
60 If the `nfsroot' parameter is NOT given on the command line,
61 the default ``"/tftpboot/%s"`` will be used.
62
63 <server-ip> Specifies the IP address of the NFS server.
64 The default address is determined by the ip parameter
65 (see below). This parameter allows the use of different
66 servers for IP autoconfiguration and NFS.
67
68 <root-dir> Name of the directory on the server to mount as root.
69 If there is a "%s" token in the string, it will be
70 replaced by the ASCII-representation of the client's
71 IP address.
72
73 <nfs-options> Standard NFS options. All options are separated by commas.
74 The following defaults are used::
75
76 port = as given by server portmap daemon
77 rsize = 4096
78 wsize = 4096
79 timeo = 7
80 retrans = 3
81 acregmin = 3
82 acregmax = 60
83 acdirmin = 30
84 acdirmax = 60
85 flags = hard, nointr, noposix, cto, ac
86
87
88ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>:<dns0-ip>:<dns1-ip>:<ntp0-ip>
89 This parameter tells the kernel how to configure IP addresses of devices
90 and also how to set up the IP routing table. It was originally called
91 nfsaddrs, but now the boot-time IP configuration works independently of
92 NFS, so it was renamed to ip and the old name remained as an alias for
93 compatibility reasons.
94
95 If this parameter is missing from the kernel command line, all fields are
96 assumed to be empty, and the defaults mentioned below apply. In general
97 this means that the kernel tries to configure everything using
98 autoconfiguration.
99
100 The <autoconf> parameter can appear alone as the value to the ip
101 parameter (without all the ':' characters before). If the value is
102 "ip=off" or "ip=none", no autoconfiguration will take place, otherwise
103 autoconfiguration will take place. The most common way to use this
104 is "ip=dhcp".
105
106 <client-ip> IP address of the client.
107 Default: Determined using autoconfiguration.
108
109 <server-ip> IP address of the NFS server.
110 If RARP is used to determine
111 the client address and this parameter is NOT empty only
112 replies from the specified server are accepted.
113
114 Only required for NFS root. That is autoconfiguration
115 will not be triggered if it is missing and NFS root is not
116 in operation.
117
118 Value is exported to /proc/net/pnp with the prefix "bootserver "
119 (see below).
120
121 Default: Determined using autoconfiguration.
122 The address of the autoconfiguration server is used.
123
124 <gw-ip> IP address of a gateway if the server is on a different subnet.
125 Default: Determined using autoconfiguration.
126
127 <netmask> Netmask for local network interface.
128 If unspecified the netmask is derived from the client IP address
129 assuming classful addressing.
130
131 Default: Determined using autoconfiguration.
132
133 <hostname> Name of the client.
134 If a '.' character is present, anything
135 before the first '.' is used as the client's hostname, and anything
136 after it is used as its NIS domain name. May be supplied by
137 autoconfiguration, but its absence will not trigger autoconfiguration.
138 If specified and DHCP is used, the user-provided hostname (and NIS
139 domain name, if present) will be carried in the DHCP request; this
140 may cause a DNS record to be created or updated for the client.
141
142 Default: Client IP address is used in ASCII notation.
143
144 <device> Name of network device to use.
145 Default: If the host only has one device, it is used.
146 Otherwise the device is determined using
147 autoconfiguration. This is done by sending
148 autoconfiguration requests out of all devices,
149 and using the device that received the first reply.
150
151 <autoconf> Method to use for autoconfiguration.
152 In the case of options
153 which specify multiple autoconfiguration protocols,
154 requests are sent using all protocols, and the first one
155 to reply is used.
156
157 Only autoconfiguration protocols that have been compiled
158 into the kernel will be used, regardless of the value of
159 this option::
160
161 off or none: don't use autoconfiguration
162 (do static IP assignment instead)
163 on or any: use any protocol available in the kernel
164 (default)
165 dhcp: use DHCP
166 bootp: use BOOTP
167 rarp: use RARP
168 both: use both BOOTP and RARP but not DHCP
169 (old option kept for backwards compatibility)
170
171 if dhcp is used, the client identifier can be used by following
172 format "ip=dhcp,client-id-type,client-id-value"
173
174 Default: any
175
176 <dns0-ip> IP address of primary nameserver.
177 Value is exported to /proc/net/pnp with the prefix "nameserver "
178 (see below).
179
180 Default: None if not using autoconfiguration; determined
181 automatically if using autoconfiguration.
182
183 <dns1-ip> IP address of secondary nameserver.
184 See <dns0-ip>.
185
186 <ntp0-ip> IP address of a Network Time Protocol (NTP) server.
187 Value is exported to /proc/net/ipconfig/ntp_servers, but is
188 otherwise unused (see below).
189
190 Default: None if not using autoconfiguration; determined
191 automatically if using autoconfiguration.
192
193 After configuration (whether manual or automatic) is complete, two files
194 are created in the following format; lines are omitted if their respective
195 value is empty following configuration:
196
197 - /proc/net/pnp:
198
199 #PROTO: <DHCP|BOOTP|RARP|MANUAL> (depending on configuration method)
200 domain <dns-domain> (if autoconfigured, the DNS domain)
201 nameserver <dns0-ip> (primary name server IP)
202 nameserver <dns1-ip> (secondary name server IP)
203 nameserver <dns2-ip> (tertiary name server IP)
204 bootserver <server-ip> (NFS server IP)
205
206 - /proc/net/ipconfig/ntp_servers:
207
208 <ntp0-ip> (NTP server IP)
209 <ntp1-ip> (NTP server IP)
210 <ntp2-ip> (NTP server IP)
211
212 <dns-domain> and <dns2-ip> (in /proc/net/pnp) and <ntp1-ip> and <ntp2-ip>
213 (in /proc/net/ipconfig/ntp_servers) are requested during autoconfiguration;
214 they cannot be specified as part of the "ip=" kernel command line parameter.
215
216 Because the "domain" and "nameserver" options are recognised by DNS
217 resolvers, /etc/resolv.conf is often linked to /proc/net/pnp on systems
218 that use an NFS root filesystem.
219
220 Note that the kernel will not synchronise the system time with any NTP
221 servers it discovers; this is the responsibility of a user space process
222 (e.g. an initrd/initramfs script that passes the IP addresses listed in
223 /proc/net/ipconfig/ntp_servers to an NTP client before mounting the real
224 root filesystem if it is on NFS).
225
226
227nfsrootdebug
228 This parameter enables debugging messages to appear in the kernel
229 log at boot time so that administrators can verify that the correct
230 NFS mount options, server address, and root path are passed to the
231 NFS client.
232
233
234rdinit=<executable file>
235 To specify which file contains the program that starts system
236 initialization, administrators can use this command line parameter.
237 The default value of this parameter is "/init". If the specified
238 file exists and the kernel can execute it, root filesystem related
239 kernel command line parameters, including 'nfsroot=', are ignored.
240
241 A description of the process of mounting the root file system can be
242 found in Documentation/driver-api/early-userspace/early_userspace_support.rst
243
244
245Boot Loader
246===========
247
248To get the kernel into memory different approaches can be used.
249They depend on various facilities being available:
250
251
252- Booting from a floppy using syslinux
253
254 When building kernels, an easy way to create a boot floppy that uses
255 syslinux is to use the zdisk or bzdisk make targets which use zimage
256 and bzimage images respectively. Both targets accept the
257 FDARGS parameter which can be used to set the kernel command line.
258
259 e.g::
260
261 make bzdisk FDARGS="root=/dev/nfs"
262
263 Note that the user running this command will need to have
264 access to the floppy drive device, /dev/fd0
265
266 For more information on syslinux, including how to create bootdisks
267 for prebuilt kernels, see https://syslinux.zytor.com/
268
269 .. note::
270 Previously it was possible to write a kernel directly to
271 a floppy using dd, configure the boot device using rdev, and
272 boot using the resulting floppy. Linux no longer supports this
273 method of booting.
274
275- Booting from a cdrom using isolinux
276
277 When building kernels, an easy way to create a bootable cdrom that
278 uses isolinux is to use the isoimage target which uses a bzimage
279 image. Like zdisk and bzdisk, this target accepts the FDARGS
280 parameter which can be used to set the kernel command line.
281
282 e.g::
283
284 make isoimage FDARGS="root=/dev/nfs"
285
286 The resulting iso image will be arch/<ARCH>/boot/image.iso
287 This can be written to a cdrom using a variety of tools including
288 cdrecord.
289
290 e.g::
291
292 cdrecord dev=ATAPI:1,0,0 arch/x86/boot/image.iso
293
294 For more information on isolinux, including how to create bootdisks
295 for prebuilt kernels, see https://syslinux.zytor.com/
296
297- Using LILO
298
299 When using LILO all the necessary command line parameters may be
300 specified using the 'append=' directive in the LILO configuration
301 file.
302
303 However, to use the 'root=' directive you also need to create
304 a dummy root device, which may be removed after LILO is run.
305
306 e.g::
307
308 mknod /dev/boot255 c 0 255
309
310 For information on configuring LILO, please refer to its documentation.
311
312- Using GRUB
313
314 When using GRUB, kernel parameter are simply appended after the kernel
315 specification: kernel <kernel> <parameters>
316
317- Using loadlin
318
319 loadlin may be used to boot Linux from a DOS command prompt without
320 requiring a local hard disk to mount as root. This has not been
321 thoroughly tested by the authors of this document, but in general
322 it should be possible configure the kernel command line similarly
323 to the configuration of LILO.
324
325 Please refer to the loadlin documentation for further information.
326
327- Using a boot ROM
328
329 This is probably the most elegant way of booting a diskless client.
330 With a boot ROM the kernel is loaded using the TFTP protocol. The
331 authors of this document are not aware of any no commercial boot
332 ROMs that support booting Linux over the network. However, there
333 are two free implementations of a boot ROM, netboot-nfs and
334 etherboot, both of which are available on sunsite.unc.edu, and both
335 of which contain everything you need to boot a diskless Linux client.
336
337- Using pxelinux
338
339 Pxelinux may be used to boot linux using the PXE boot loader
340 which is present on many modern network cards.
341
342 When using pxelinux, the kernel image is specified using
343 "kernel <relative-path-below /tftpboot>". The nfsroot parameters
344 are passed to the kernel by adding them to the "append" line.
345 It is common to use serial console in conjunction with pxeliunx,
346 see Documentation/admin-guide/serial-console.rst for more information.
347
348 For more information on isolinux, including how to create bootdisks
349 for prebuilt kernels, see https://syslinux.zytor.com/
350
351
352
353
354Credits
355=======
356
357 The nfsroot code in the kernel and the RARP support have been written
358 by Gero Kuhlmann <gero@gkminix.han.de>.
359
360 The rest of the IP layer autoconfiguration code has been written
361 by Martin Mares <mj@atrey.karlin.mff.cuni.cz>.
362
363 In order to write the initial version of nfsroot I would like to thank
364 Jens-Uwe Mager <jum@anubis.han.de> for his help.
1===============================================
2Mounting the root filesystem via NFS (nfsroot)
3===============================================
4
5:Authors:
6 Written 1996 by Gero Kuhlmann <gero@gkminix.han.de>
7
8 Updated 1997 by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
9
10 Updated 2006 by Nico Schottelius <nico-kernel-nfsroot@schottelius.org>
11
12 Updated 2006 by Horms <horms@verge.net.au>
13
14 Updated 2018 by Chris Novakovic <chris@chrisn.me.uk>
15
16
17
18In order to use a diskless system, such as an X-terminal or printer server for
19example, it is necessary for the root filesystem to be present on a non-disk
20device. This may be an initramfs (see
21Documentation/filesystems/ramfs-rootfs-initramfs.rst), a ramdisk (see
22Documentation/admin-guide/initrd.rst) or a filesystem mounted via NFS. The
23following text describes on how to use NFS for the root filesystem. For the rest
24of this text 'client' means the diskless system, and 'server' means the NFS
25server.
26
27
28
29
30Enabling nfsroot capabilities
31=============================
32
33In order to use nfsroot, NFS client support needs to be selected as
34built-in during configuration. Once this has been selected, the nfsroot
35option will become available, which should also be selected.
36
37In the networking options, kernel level autoconfiguration can be selected,
38along with the types of autoconfiguration to support. Selecting all of
39DHCP, BOOTP and RARP is safe.
40
41
42
43
44Kernel command line
45===================
46
47When the kernel has been loaded by a boot loader (see below) it needs to be
48told what root fs device to use. And in the case of nfsroot, where to find
49both the server and the name of the directory on the server to mount as root.
50This can be established using the following kernel command line parameters:
51
52
53root=/dev/nfs
54 This is necessary to enable the pseudo-NFS-device. Note that it's not a
55 real device but just a synonym to tell the kernel to use NFS instead of
56 a real device.
57
58
59nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>]
60 If the `nfsroot' parameter is NOT given on the command line,
61 the default ``"/tftpboot/%s"`` will be used.
62
63 <server-ip> Specifies the IP address of the NFS server.
64 The default address is determined by the ip parameter
65 (see below). This parameter allows the use of different
66 servers for IP autoconfiguration and NFS.
67
68 <root-dir> Name of the directory on the server to mount as root.
69 If there is a "%s" token in the string, it will be
70 replaced by the ASCII-representation of the client's
71 IP address.
72
73 <nfs-options> Standard NFS options. All options are separated by commas.
74 The following defaults are used::
75
76 port = as given by server portmap daemon
77 rsize = 4096
78 wsize = 4096
79 timeo = 7
80 retrans = 3
81 acregmin = 3
82 acregmax = 60
83 acdirmin = 30
84 acdirmax = 60
85 flags = hard, nointr, noposix, cto, ac
86
87
88ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>:<dns0-ip>:<dns1-ip>:<ntp0-ip>
89 This parameter tells the kernel how to configure IP addresses of devices
90 and also how to set up the IP routing table. It was originally called
91 nfsaddrs, but now the boot-time IP configuration works independently of
92 NFS, so it was renamed to ip and the old name remained as an alias for
93 compatibility reasons.
94
95 If this parameter is missing from the kernel command line, all fields are
96 assumed to be empty, and the defaults mentioned below apply. In general
97 this means that the kernel tries to configure everything using
98 autoconfiguration.
99
100 The <autoconf> parameter can appear alone as the value to the ip
101 parameter (without all the ':' characters before). If the value is
102 "ip=off" or "ip=none", no autoconfiguration will take place, otherwise
103 autoconfiguration will take place. The most common way to use this
104 is "ip=dhcp".
105
106 <client-ip> IP address of the client.
107 Default: Determined using autoconfiguration.
108
109 <server-ip> IP address of the NFS server.
110 If RARP is used to determine
111 the client address and this parameter is NOT empty only
112 replies from the specified server are accepted.
113
114 Only required for NFS root. That is autoconfiguration
115 will not be triggered if it is missing and NFS root is not
116 in operation.
117
118 Value is exported to /proc/net/pnp with the prefix "bootserver "
119 (see below).
120
121 Default: Determined using autoconfiguration.
122 The address of the autoconfiguration server is used.
123
124 <gw-ip> IP address of a gateway if the server is on a different subnet.
125 Default: Determined using autoconfiguration.
126
127 <netmask> Netmask for local network interface.
128 If unspecified the netmask is derived from the client IP address
129 assuming classful addressing.
130
131 Default: Determined using autoconfiguration.
132
133 <hostname> Name of the client.
134 If a '.' character is present, anything
135 before the first '.' is used as the client's hostname, and anything
136 after it is used as its NIS domain name. May be supplied by
137 autoconfiguration, but its absence will not trigger autoconfiguration.
138 If specified and DHCP is used, the user-provided hostname (and NIS
139 domain name, if present) will be carried in the DHCP request; this
140 may cause a DNS record to be created or updated for the client.
141
142 Default: Client IP address is used in ASCII notation.
143
144 <device> Name of network device to use.
145 Default: If the host only has one device, it is used.
146 Otherwise the device is determined using
147 autoconfiguration. This is done by sending
148 autoconfiguration requests out of all devices,
149 and using the device that received the first reply.
150
151 <autoconf> Method to use for autoconfiguration.
152 In the case of options
153 which specify multiple autoconfiguration protocols,
154 requests are sent using all protocols, and the first one
155 to reply is used.
156
157 Only autoconfiguration protocols that have been compiled
158 into the kernel will be used, regardless of the value of
159 this option::
160
161 off or none: don't use autoconfiguration
162 (do static IP assignment instead)
163 on or any: use any protocol available in the kernel
164 (default)
165 dhcp: use DHCP
166 bootp: use BOOTP
167 rarp: use RARP
168 both: use both BOOTP and RARP but not DHCP
169 (old option kept for backwards compatibility)
170
171 if dhcp is used, the client identifier can be used by following
172 format "ip=dhcp,client-id-type,client-id-value"
173
174 Default: any
175
176 <dns0-ip> IP address of primary nameserver.
177 Value is exported to /proc/net/pnp with the prefix "nameserver "
178 (see below).
179
180 Default: None if not using autoconfiguration; determined
181 automatically if using autoconfiguration.
182
183 <dns1-ip> IP address of secondary nameserver.
184 See <dns0-ip>.
185
186 <ntp0-ip> IP address of a Network Time Protocol (NTP) server.
187 Value is exported to /proc/net/ipconfig/ntp_servers, but is
188 otherwise unused (see below).
189
190 Default: None if not using autoconfiguration; determined
191 automatically if using autoconfiguration.
192
193 After configuration (whether manual or automatic) is complete, two files
194 are created in the following format; lines are omitted if their respective
195 value is empty following configuration:
196
197 - /proc/net/pnp:
198
199 #PROTO: <DHCP|BOOTP|RARP|MANUAL> (depending on configuration method)
200 domain <dns-domain> (if autoconfigured, the DNS domain)
201 nameserver <dns0-ip> (primary name server IP)
202 nameserver <dns1-ip> (secondary name server IP)
203 nameserver <dns2-ip> (tertiary name server IP)
204 bootserver <server-ip> (NFS server IP)
205
206 - /proc/net/ipconfig/ntp_servers:
207
208 <ntp0-ip> (NTP server IP)
209 <ntp1-ip> (NTP server IP)
210 <ntp2-ip> (NTP server IP)
211
212 <dns-domain> and <dns2-ip> (in /proc/net/pnp) and <ntp1-ip> and <ntp2-ip>
213 (in /proc/net/ipconfig/ntp_servers) are requested during autoconfiguration;
214 they cannot be specified as part of the "ip=" kernel command line parameter.
215
216 Because the "domain" and "nameserver" options are recognised by DNS
217 resolvers, /etc/resolv.conf is often linked to /proc/net/pnp on systems
218 that use an NFS root filesystem.
219
220 Note that the kernel will not synchronise the system time with any NTP
221 servers it discovers; this is the responsibility of a user space process
222 (e.g. an initrd/initramfs script that passes the IP addresses listed in
223 /proc/net/ipconfig/ntp_servers to an NTP client before mounting the real
224 root filesystem if it is on NFS).
225
226
227nfsrootdebug
228 This parameter enables debugging messages to appear in the kernel
229 log at boot time so that administrators can verify that the correct
230 NFS mount options, server address, and root path are passed to the
231 NFS client.
232
233
234rdinit=<executable file>
235 To specify which file contains the program that starts system
236 initialization, administrators can use this command line parameter.
237 The default value of this parameter is "/init". If the specified
238 file exists and the kernel can execute it, root filesystem related
239 kernel command line parameters, including 'nfsroot=', are ignored.
240
241 A description of the process of mounting the root file system can be
242 found in Documentation/driver-api/early-userspace/early_userspace_support.rst
243
244
245Boot Loader
246===========
247
248To get the kernel into memory different approaches can be used.
249They depend on various facilities being available:
250
251
252- Booting from a floppy using syslinux
253
254 When building kernels, an easy way to create a boot floppy that uses
255 syslinux is to use the zdisk or bzdisk make targets which use zimage
256 and bzimage images respectively. Both targets accept the
257 FDARGS parameter which can be used to set the kernel command line.
258
259 e.g::
260
261 make bzdisk FDARGS="root=/dev/nfs"
262
263 Note that the user running this command will need to have
264 access to the floppy drive device, /dev/fd0
265
266 For more information on syslinux, including how to create bootdisks
267 for prebuilt kernels, see https://syslinux.zytor.com/
268
269 .. note::
270 Previously it was possible to write a kernel directly to
271 a floppy using dd, configure the boot device using rdev, and
272 boot using the resulting floppy. Linux no longer supports this
273 method of booting.
274
275- Booting from a cdrom using isolinux
276
277 When building kernels, an easy way to create a bootable cdrom that
278 uses isolinux is to use the isoimage target which uses a bzimage
279 image. Like zdisk and bzdisk, this target accepts the FDARGS
280 parameter which can be used to set the kernel command line.
281
282 e.g::
283
284 make isoimage FDARGS="root=/dev/nfs"
285
286 The resulting iso image will be arch/<ARCH>/boot/image.iso
287 This can be written to a cdrom using a variety of tools including
288 cdrecord.
289
290 e.g::
291
292 cdrecord dev=ATAPI:1,0,0 arch/x86/boot/image.iso
293
294 For more information on isolinux, including how to create bootdisks
295 for prebuilt kernels, see https://syslinux.zytor.com/
296
297- Using LILO
298
299 When using LILO all the necessary command line parameters may be
300 specified using the 'append=' directive in the LILO configuration
301 file.
302
303 However, to use the 'root=' directive you also need to create
304 a dummy root device, which may be removed after LILO is run.
305
306 e.g::
307
308 mknod /dev/boot255 c 0 255
309
310 For information on configuring LILO, please refer to its documentation.
311
312- Using GRUB
313
314 When using GRUB, kernel parameter are simply appended after the kernel
315 specification: kernel <kernel> <parameters>
316
317- Using loadlin
318
319 loadlin may be used to boot Linux from a DOS command prompt without
320 requiring a local hard disk to mount as root. This has not been
321 thoroughly tested by the authors of this document, but in general
322 it should be possible configure the kernel command line similarly
323 to the configuration of LILO.
324
325 Please refer to the loadlin documentation for further information.
326
327- Using a boot ROM
328
329 This is probably the most elegant way of booting a diskless client.
330 With a boot ROM the kernel is loaded using the TFTP protocol. The
331 authors of this document are not aware of any no commercial boot
332 ROMs that support booting Linux over the network. However, there
333 are two free implementations of a boot ROM, netboot-nfs and
334 etherboot, both of which are available on sunsite.unc.edu, and both
335 of which contain everything you need to boot a diskless Linux client.
336
337- Using pxelinux
338
339 Pxelinux may be used to boot linux using the PXE boot loader
340 which is present on many modern network cards.
341
342 When using pxelinux, the kernel image is specified using
343 "kernel <relative-path-below /tftpboot>". The nfsroot parameters
344 are passed to the kernel by adding them to the "append" line.
345 It is common to use serial console in conjunction with pxeliunx,
346 see Documentation/admin-guide/serial-console.rst for more information.
347
348 For more information on isolinux, including how to create bootdisks
349 for prebuilt kernels, see https://syslinux.zytor.com/
350
351
352
353
354Credits
355=======
356
357 The nfsroot code in the kernel and the RARP support have been written
358 by Gero Kuhlmann <gero@gkminix.han.de>.
359
360 The rest of the IP layer autoconfiguration code has been written
361 by Martin Mares <mj@atrey.karlin.mff.cuni.cz>.
362
363 In order to write the initial version of nfsroot I would like to thank
364 Jens-Uwe Mager <jum@anubis.han.de> for his help.