rk3399_rockchip-uboot/doc/README.pxe

8 the PXELINUX boot loader. This allows U-Boot based systems to be controlled
24      'pxe get' requires two environment variables to be set:
26      pxefile_addr_r - should be set to a location in RAM large enough to hold
27      pxe files while they're being processed. Up to 16 config files may be
33      handler, and correspond to fields in the DHCP response.
38      'pxe get' uses it to look for a configuration file specific to a system's
43      it to look for a configuration file based on the system's UUID.
47      'pxe get' repeatedly tries to download config files until it either
48      successfully downloads one or runs out of paths to try. The order and
65      There are some environment variables that may need to be set, depending
73      same field in the DHCP respone, this path is used to generate the base
74      directory that all other paths to files retrieved by 'pxe boot' will use.
82      locations will be passed to the bootm command to boot the kernel. These
83      environment variables are required to be set.
88      will be passed to bootm command to boot the kernel.
90      fdt_addr - the location of a fdt blob. 'fdt_addr' will be passed to bootm
91      command if it is set and 'fdt_addr_r' is not passed to bootm command.
97 commands - global commands, and commands specific to labels. Lines begining
102 of RAM available to U-Boot. Memory for labels is dynamically allocated as
113 		      the first label 'pxe boot' attempts to boot.
117 menu include <path> - use tftp to retrieve the pxe file at <path>, which
120 		      of include up to 16 files deep is supported.
122 prompt <flag>	    - if 1, always prompt the user to enter a label to boot
136 menu default	    - set this label as the default label to boot; this is
140 kernel <path>	    - if this label is chosen, use tftp to retrieve the kernel
143 		      that address will be passed to bootm to boot this kernel.
148 initrd <path>	    - if this label is chosen, use tftp to retrieve the initrd
151 		      will be passed to bootm.
153 fdt <path>	    - if this label is chosen, use tftp to retrieve the fdt blob
156 		      be passed to bootm.
158 fdtdir <path>	    - if this label is chosen, use tftp to retrieve a fdt blob
159 		      relative to <path>. If the fdtfile environment variable
166 		      <flag> is ignored and is only here to match the syntax of
171 Here's a couple of example files to show how this works.
205 to be downloaded, and boot with the command line "root=/dev/sdb1"
215   in RFC 5071, but could be extended to do so.
217 - when U-Boot's pxe fails to boot, it will return control to U-Boot,
218   allowing another command to run, other U-Boot command, instead of resetting
226   this README.	With PXELINUX, it's possible to have a graphical boot
227   menu, submenus, passwords, etc. U-Boot's pxe could be extended to support
234   could be extended to support multiple.
241 - the interactive prompt in U-Boot's pxe only allows you to choose a label
242   from the menu.  If you want to boot something not listed, you can ctrl+c
243   out of 'pxe boot' and use existing U-Boot commands to accomplish it.