u-boot/doc/README.pxe

6 The 'pxe' commands provide a near subset of the functionality provided by
14 pxe get
16      syntax: pxe get
23      'pxe get' requires two environment variables to be set:
26      pxe files while they're being processed. Up to 16 config files may be
34      'pxe get' optionally supports these two environment variables being set:
37      'pxe get' uses it to look for a configuration file specific to a system's
41      digits, for example, 550e8400-e29b-41d4-a716-446655440000. 'pxe get' uses
46      'pxe get' repeatedly tries to download config files until it either
53 pxe boot
55      syntax: pxe boot [pxefile_addr_r]
57      Interprets a pxe file stored in memory.
59      pxefile_addr_r is an optional argument giving the location of the pxe file.
69      typically the same value as is used for the 'pxe get' command.
73      directory that all other paths to files retrieved by 'pxe boot' will use.
74      If no bootfile is specified, paths used in pxe files will be used as is.
79      kernel_addr_r, initrd_addr_r - locations in RAM at which 'pxe boot' will
84      fdt_addr_r - location in RAM at which 'pxe boot' will store the fdt blob it
86      pxe file and 'fdt_addr_r' is set. If retrieval is possible, 'fdt_addr_r'
92 pxe file format
94 The pxe file format is nearly a subset of the PXELINUX file format; see
100 The size of pxe files and the number of labels is only limited by the amount
102 they're parsed, and memory for pxe files is statically allocated, and its
103 location is given by the pxefile_addr_r environment variable. The pxe code is
104 not aware of the size of the pxefile memory and will outgrow it if pxe files
112 		      the first label 'pxe boot' attempts to boot.
116 menu include <path> - use tftp to retrieve the pxe file at <path>, which
148 		      It useful for overlay selection in pxe file
208 When a pxe client retrieves and boots the default pxe file,
209 'pxe boot' will wait for user input for 5 seconds before booting
215 The biggest difference between U-Boot's pxe and PXELINUX is that since
216 U-Boot's pxe support is written entirely in C, it can run on any platform
218 PXELINUX and U-Boot's pxe support.
220 - U-Boot's pxe does not support the PXELINUX DHCP option codes specified
223 - when U-Boot's pxe fails to boot, it will return control to U-Boot,
227 - U-Boot's pxe doesn't rely on or provide an UNDI/PXE stack in memory, it
230 - U-Boot's pxe doesn't provide the full menu implementation that PXELINUX
233   menu, submenus, passwords, etc. U-Boot's pxe could be extended to support
236 - U-Boot's pxe expects U-Boot uimg's as kernels.  Anything that would work
237   with the 'bootm' command in U-Boot could work with the 'pxe boot' command.
239 - U-Boot's pxe only recognizes a single file on the initrd command line.  It
242 - in U-Boot's pxe, the localboot command doesn't necessarily cause a local
247 - the interactive prompt in U-Boot's pxe only allows you to choose a label
249   out of 'pxe boot' and use existing U-Boot commands to accomplish it.