It might be the case that we wish to chain to an NBP without
being "in the way". We now implement a hook in our exit path
for gPXE *.*pxe build targets. The hook is a pointer to a
SEG16:OFF16 which we try to jump to during exit. By default,
this pointer results in the usual exit path.
We also implement the "pxenv_file_exit_hook" PXE API routine
to allow the user to specify an alternate SEG16:OFF16 to jump
to during exit.
Unfortunately, this additional PXE extension has a cost
in code size. Fortunately, a look at the size difference
for a gPXE .rom build target shows zero size difference
after compression.
The routine is documented in doc/pxe_extensions as follows:
FILE EXIT HOOK
Op-Code: PXENV_FILE_EXIT_HOOK (00e7h)
Input: Far pointer to a t_PXENV_FILE_EXIT_HOOK parameter
structure that has been initialized by the caller.
Output: PXENV_EXIT_SUCCESS or PXENV_EXIT_FAILURE must be
returned in AX. The Status field in the parameter
structure must be set to one of the values represented
by the PXENV_STATUS_xxx constants.
Description:Modify the exit path to jump to the specified code.
Only valid for pxeprefix-based builds.
typedef struct s_PXENV_FILE_EXIT_HOOK {
PXENV_STATUS_t Status;
SEGOFF16_t Hook;
} t_PXENV_FILE_EXIT_HOOK;
Set before calling API service:
Hook: The SEG16:OFF16 of the code to jump to.
Returned from API service:
Status: See PXENV_STATUS_xxx constants.
Requested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>
Signed-off-by: Marty Connor <mdc@etherboot.org>
[pxe] Dual-license pxe_api.h under the MIT license
pxe_api.h is just a description of API functions, it's actively
undesirable to have more implementations than necessary. Allowing it
under the MIT license lets the Syslinux libraries use it.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Michael Brown <mcb30@etherboot.org>
[pxe] Fix interoperability with the Intel DOS UNDI driver
The Intel DOS UNDI driver fails when run on top of gPXE because we do
not fill in the ServiceFlags field in PXENV_UNDI_GET_IFACE_INFO.
Fix by filling in the ServiceFlags field with reasonable values
indicating our approximate feature capabilities.
[PXEXT] Add PXENV_FILE_EXEC call to PXE extensions API.
This allows pxelinux to execute arbitrary gPXE commands. This is
remarkably unsafe (not least because some of the commands will assume
full ownership of memory and do nasty things like edit the e820 map
underneath the calling pxelinux), but it does allow access to the
"sanboot" command.