Microsoft WDS can end up calling PXENV_RESTART_TFTP to execute a
second-stage NBP which then exits. Specifically, wdsnbp.com uses
PXENV_RESTART_TFTP to execute pxeboot.com, which will exit if the user
does not press F12. iPXE currently treats PXENV_RESTART_TFTP as a
normal PXE API call, and so attempts to return to wdsnbp.com, which
has just been vaporised by pxeboot.com.
Use rmsetjmp/rmlongjmp to preserve the stack state as of the initial
NBP execution, and to restore this state immediately prior to
executing the NBP loaded via PXENV_RESTART_TFTP. This matches the
behaviour in the PXE spec (which says that "if TFTP is restarted,
control is never returned to the caller"), and allows pxeboot.com to
exit relatively cleanly back to iPXE.
As with all usage of setjmp/longjmp, there may be subtle corner case
bugs due to not gracefully unwinding any state accumulated by the time
of the longjmp call, but this seems to be the only viable way to
provide the specified behaviour.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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>
For extremely tight space requirements and specific applications, it is
sometimes desirable to create gPXE images that cannot provide the PXE API
functionality to client programs. Add a configuration header option,
PXE_STACK, that can be removed to remove this stack. Also add PXE_MENU
to control the PXE boot menu, which most uses of gPXE do not need.
Signed-off-by: Marty Connor <mdc@etherboot.org>
pxe_init_structures() fills in the fields of the !PXE and PXENV+
structures that aren't known until gPXE starts up. Once gPXE is
started, these values will never change.
Make pxe_init_structures() an initialisation function so that PXE
users don't have to worry about calling it.
The PXE 1.x spec specifies that on NBP entry or on return from INT
1Ah AX=5650h, EDX shall point to the physical address of the PXENV+
structure. The PXE 2.x spec drops this requirement, simply stating
that EDX is clobbered. Given the principle "be conservative in what
you send, liberal in what you accept", however, we should implement
this anyway.
IBM's iSCSI Firmware Initiator checks the UNDIROMID pointer in the
!PXE structure that gets created by the UNDI loader. We didn't
previously fill this value in.
__from_data16 and __from_text16 now take a pointer to a
.data16/.text16 variable, and return the real-mode offset within the
appropriate segment. This matches the use case for every occurrence
of these macros, and prevents potential future bugs such as that fixed
in commit d51d80f. (The bug arose essentially because "&pointer" is
still syntactically valid.)
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.
defined in vsprintf.h. (This may change, since vsprintf.h is a
non-standard name, but for now it's the one to use.)
There should be no need to include vsprintf.h just for DBG() statements,
since include/compiler.h forces it in for a debug build anyway.
Updated PXE API dispatcher to use copy_{to,from}_user, and moved to
arch/i386 since the implementation is quite architecture-dependent.
(The individual PXE API calls can be largely
architecture-independent.)
Michael Brown
Shao Miller
Joshua Oreman
Michael Brown
H. Peter Anvin
Marty Connor