Differences

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--- httpboot [2009/02/11 17:50]
gluneau
+++ httpboot [2010/10/14 04:39] (current)
dali
@@ Line 1: / Line 1: @@
 ====== HTTP booting ======
-{{ screenshots/uniboot1.png?360x200|Linux booting via HTTP}}
 Booting from HTTP with gPXE is as simple as replacing the DHCP filename field with an %%http://%% URL.  For example, if you currently have ///etc/dhcpd.conf// containing
@@ Line 12: / Line 10: @@
     filename "http://my.web.server/pxe.0";
+{{ screenshots/uniboot1.png?360x200|Linux booting via HTTP}}
-===== Boot file content =====
+===== Scalability =====
-You can use any of the commands found in the [[commandline|gPXE command line reference]] as instructions booting your OS.
+HTTP can handle much larger files than TFTP, and scale to much larger distances.  You can easily download multi-megabyte files, such as a Linux kernel and a root filesystem, and you can download from servers that are not on your local area network.  We have successfully tested booting across the Atlantic using HTTP!
+===== Using PXELINUX =====
-For example http://etherboot.com/gtest/gtest.gpxe file contains the following gPXE commands:
+PXELINUX versions >= 3.70 can use gPXE-provided HTTP.  (See syslinux/NEWS "Changes in 3.70")
-    #!gpxe
+By default, PXELINUX will look for its configuration file using TFTP.  To override this behaviour, you can specify DHCP options 209 and/or 210.  (See syslinux/doc/rfc5071.txt)
-    kernel http://etherboot.org/gtest/bz2bzImage root=100
-    initrd http://etherboot.org/gtest/initrd.bz2
-    boot
-or this will boot from iSCSI:
+You can specify these options with your DHCP service or you can specify them in a gPXE script:
     #!gpxe
-    sanboot iscsi:192.168.2.23::::iqn.1994-04.org.netbsd.iscsi-target:target1
+    echo Performing DHCP on first network interface
+    dhcp net0
+    set 209:string pxelinux.cfg/default
+    set 210:string http://example.com/
+    chain ${210:string}pxelinux.0
+The 'chain' command above will be expanded by gPXE to:
+  chain http://example.com/pxelinux.0
+and the chained-to PXELINUX will look for its configuration file using the 210 prefix.
+All relative paths specified in the PXELINUX configuration file will also have this prefix
+prepended to them.
+===== Using gpxelinux.0 =====
-===== Scalability =====
+Since SYSLINUX 3.85 there is also the option of using gpxelinux.0 with pxelinux.0 embedded, example:
+<code text>
-HTTP can handle much larger files than TFTP, and scale to much larger distances.  You can easily download multi-megabyte files, such as a Linux kernel and a root filesystem, and you can download from servers that are not on your local area network.  We have successfully tested booting across the Atlantic using HTTP!
+#!gpxe
+echo Performing DHCP on first network interface
+dhcp net0
+set 209:string pxelinux.cfg/default
+set 210:string http://example.com/
+imgload pxelinux.0
+boot pxelinux.0
+</code>