Some versions of Linux apparently complain if initrds are not aligned
to a page boundary. Fix by changing INITRD_ALIGN from 4 bytes to 4096
bytes.
The amount of padding at the end of each initrd will now often be
sufficient to allow the cpio header to be prepended without crossing
an alignment boundary. The final location of the initrd may therefore
end up being slightly higher than the post-shuffle location.
bzimage_load_initrd() must therefore now copy the initrd body prior to
copying the cpio header, otherwise the start of the initrd body may be
overwritten by the cpio header. (Note that the guarantee that an
initrd will never need to overwrite an initrd at a higher location
still holds, since the overall length of each initrd cannot decrease
as a result of adding a cpio header.)
Reported-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
At present, loading a bzImage via iPXE requires enough RAM to hold two
copies of each initrd file. Remove this constraint by rearranging the
initrds in place.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Do not zero %edx when jumping to a boot sector
Commit 73eb3f1 ("[int13] Zero all possible registers when jumping to a
boot sector") introduced a regression preventing the SAN-booting of
boot sectors which rely upon %dl containing the correct drive number
(such as most CD-ROM boot sectors).
Fix by not zeroing %edx.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Zero all possible registers when jumping to a boot sector
At least one boot sector (the DUET boot sector used for bootstrapping
EFI from a non-EFI system) fails to initialise the high words of
registers before using them in calculations, leading to undefined
behaviour.
Work around such broken boot sectors by explicitly zeroing the
contents of all registers apart from %cs:%ip and %ss:%sp.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[comboot] Accept only ".cbt" as an extension for COMBOOT images
COMBOOT images are detected by looking for a ".com" or ".cbt" filename
extension. There are widely-used files with a ".com" extension, such
as "wdsnbp.com", which are PXE images rather than COMBOOT images.
Avoid false detection of PXE images as COMBOOT images by accepting
only a ".cbt" extension as indicating a COMBOOT image.
Interestingly, this bug has been present for a long time but was
frequently concealed because the filename was truncated to fit the
fixed-length "name" field in struct image. (PXE binaries ending in
".com" tend to be related to Windows deployment products and so often
use pathnames including backslashes, which iPXE doesn't recognise as a
path separator and so treats as part of a very long filename.)
Commit 1c127a6 ("[image] Simplify image management commands and
internal API") made the image name a variable-length field, and so
exposed this flaw in the COMBOOT image detection algorithm.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Attempt to restore the network device to the state it was in prior to
calling the NBP. This simplifies the task of taking follow-up action
in an iPXE script.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[bzimage] Update setup_move_size only for protocol versions 2.00 and 2.01
The setup_move_size field is not defined in protocol versions earlier
than 2.00 (and is obsolete in versions later than 2.01). In binaries
using versions earlier than 2.00, the relevant location is likely to
contain executable code.
Interestingly, this bug has been present since support for pre-2.00
protocol versions was added in 2009, and has been unexpectedly
modifying the memtest86+ code fragment:
mov $0x92, %dx
inb %dx, %al
Fortuitously, the modification exactly overwrote the value loaded into
%dx, and so the net effect was limited to causing Fast Gate A20
detection to always fail.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Solaris assumes that there is enough space above the Multiboot modules
to use as a decompression and scratch area. This assumption is
invalid when using iPXE, which places the Multiboot modules near the
top of (32-bit) memory.
Fix by copying the modules to an area of memory immediately following
the loaded kernel.
Debugged-by: Michael Brown <mcb30@ipxe.org>
Debugged-by: Scott McWhirter <scottm@joyent.com>
Tested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[multiboot] Include full image URI in command line
Solaris kernels seem to rely on having the full kernel path present in
the multiboot command line; if only the kernel name is present then
the boot fails with the error message
krtld: failed to open 'unix'
Debugged-by: Michael Brown <mcb30@ipxe.org>
Debugged-by: Scott McWhirter <scottm@joyent.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Refactor the {load,exec} image operations as {probe,exec}. This makes
the probe mechanism cleaner, eliminates some forward declarations,
avoids holding magic state in image->priv, eliminates the possibility
of screwing up between the "load" and "exec" stages, and makes the
documentation simpler since the concept of "loading" (as distinct from
"executing") no longer needs to be explained.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Remove the concept of shutdown exit flags, and replace it with a
counter used to keep track of exposed interfaces that require devices
to remain active.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[block] Replace gPXE block-device API with an iPXE asynchronous interface
The block device interface used in gPXE predates the invention of even
the old gPXE data-transfer interface, let alone the current iPXE
generic asynchronous interface mechanism. Bring this old code up to
date, with the following benefits:
o Block device commands can be cancelled by the requestor. The INT 13
layer uses this to provide a global timeout on all INT 13 calls,
with the result that an unexpected passive failure mode (such as
an iSCSI target ACKing the request but never sending a response)
will lead to a timeout that gets reported back to the INT 13 user,
rather than simply freezing the system.
o INT 13,00 (reset drive) is now able to reset the underlying block
device. INT 13 users, such as DOS, that use INT 13,00 as a method
for error recovery now have a chance of recovering.
o All block device commands are tagged, with a numerical tag that
will show up in debugging output and in packet captures; this will
allow easier interpretation of bug reports that include both
sources of information.
o The extremely ugly hacks used to generate the boot firmware tables
have been eradicated and replaced with a generic acpi_describe()
method (exploiting the ability of iPXE interfaces to pass through
methods to an underlying interface). The ACPI tables are now
built in a shared data block within .bss16, rather than each
requiring dedicated space in .data16.
o The architecture-independent concept of a SAN device has been
exposed to the iPXE core through the sanboot API, which provides
calls to hook, unhook, boot, and describe SAN devices. This
allows for much more flexible usage patterns (such as hooking an
empty SAN device and then running an OS installer via TFTP).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
pcbios specific get_memmap() is used by the b44 driver making
all-drivers builds fail on other platforms. Move it to the I/O API
group and provide a dummy implementation on EFI.
Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
COM32 binaries generally expect to run with interrupts
enabled. Syslinux does so, and COM32 programs will execute cli/sti
pairs when running a critical section, to provide mutual exclusion
against BIOS interrupt handlers. Previously, under iPXE, the IDT was
not valid, so any interrupt (e.g. a timer tick) would generally cause
the machine to triple fault.
This change introduces code to:
- Create a valid IDT at the same location that syslinux uses
- Create an "interrupt jump buffer", which contains small pieces of
code that simply record the vector number and jump to a common
handler
- Thunk down to real mode and execute the BIOS's interrupt handler
whenever an interrupt is received in a COM32 program
- Switch IDTs and enable/disable interrupts when context switching to
and from COM32 binaries
Testing done:
- Booted VMware ESX using a COM32 multiboot loader (mboot.c32)
- Built with GDBSERIAL enabled, and tested breakpoints on int22 and
com32_irq
- Put the following code in a COM32 program:
asm volatile ( "sti" );
while ( 1 );
Before this change, the machine would triple fault
immediately. After this change, it hangs as expected. Under Bochs,
it is possible to see the interrupt handler run, and the current
time in the BIOS data area gets incremented.
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[librm] Use libflat to enable A20 line on each real-to-protected transition
Use the shared code in libflat to perform the A20 transitions
automatically on each transition from real to protected mode. This
allows us to remove all explicit calls to gateA20_set().
The old warnings about avoiding automatically enabling A20 are
essentially redundant; they date back to the time when we would always
start hammering the keyboard controller without first checking to see
if gate A20 was already enabled (which it almost always is).
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>
[multiboot] Build memory map after shutting down and unhiding gPXE
The Multiboot memory map needs to be built after unhiding gPXE and
downloaded images from memory. Solaris faults during boot when trying
to access the ramdisk, which is hidden from the memory map while gPXE is
executing. This issue is fixed by using the memory map from after gPXE
unhides itself.
Reported-by: Moinak Ghosh <moinakg@belenix.org>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
[pxe] Make pxe_init_structures() an initialisation function
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.
[multiboot] Work around raw-flag bug in Solaris kernels
Solaris kernels are multiboot images with the "raw" flag set,
indicating that the loader should use the raw address fields within
the multiboot header rather than looking for an ELF header. However,
the Solaris kernel contains garbage data in the raw address fields,
and requires us to use the ELF header instead.
Work around this by always using the ELF header if present. This
renders the "raw" flag somewhat redundant.
[bzimage] Support old (pre-2.00 bootloader) Linux kernel formats
This allows gPXE to load memtest86, which is packaged as an old kernel.
Split all code that directly touches the kernel headers out into
bzimage_parse_header() and bzimage_update_header(), to reduce code
size and offset the cost of supporting older kernels.
Total cost of this feature: 11 bytes (uncompressed).
[comboot] Restore the real-mode stack pointer on exit from a COMBOOT image
COMBOOT images use INTs to issue API calls; these end up making calls
into gPXE from real mode, and so temporarily change the real-mode
stack pointer. When our COMBOOT code uses a longjmp() to implement
the various "exit COMBOOT image" API calls, this leaves the real-mode
stack pointer stuck with its temporary value, which causes problems if
we eventually try to exit out of gPXE back to the BIOS.
Fix by adding rmsetjmp() and rmlongjmp() calls (analogous to
sigsetjmp()/siglongjmp()); these save and restore the additional state
needed for real-mode calls to function correctly.
[comboot] Allow for tail recursion of COMBOOT images
Multi-level menus via COMBOOT rely on the COMBOOT program being able
to exit and invoke a new COMBOOT program (the next menu). This works,
but rapidly (within about five iterations) runs out of space in gPXE's
internal stack, since each new image is executed in a new function
context.
Fix by allowing tail recursion between images; an image can now
specify a replacement image for itself, and image_exec() will perform
the necessary tail recursion.
[netdevice] Kill off the various guess_boot_netdev() functions
Remove the assortment of miscellaneous hacks to guess the "network
boot device", and replace them each with a call to last_opened_netdev().
It still isn't guaranteed correct, but it won't be any worse than
before, and it will at least be consistent.
[i386] Change [u]int32_t to [unsigned] int, rather than [unsigned] long
This brings us in to line with Linux definitions, and also simplifies
adding x86_64 support since both platforms have 2-byte shorts, 4-byte
ints and 8-byte long longs.
This function is a major kludge, but can be made slightly more
accurate by ignoring net devices that aren't open. Eventually it
needs to be removed entirely.
[multiboot] Allow for unspecified {load,bss}_end_addr for raw images
The multiboot specification states that, for raw images, if
load_end_addr is zero then it should be interpreted as meaning "use
the entire file", and if bss_end_addr is zero it should be interpreted
as meaning "no bss".
[iSCSI] Support Windows Server 2008 direct iSCSI installation
Add yet another ugly hack to iscsiboot.c, this time to allow the user to
inhibit the shutdown/removal of the iSCSI INT13 device (and the network
devices, since they are required for the iSCSI device to function).
On the plus side, the fact that shutdown() now takes flags to
differentiate between shutdown-for-exit and shutdown-for-boot means that
another ugly hack (to allow returning via the PXE stack on BIOSes that
have broken INT 18 calls) will be easier.
I feel dirty.
We can just treat all non-kernel images as initrds, which matches our
behaviour for multiboot kernels. This allows us to eliminate initrd as
an image type, and treat the "initrd" command as just another synonym for
"imgfetch".
[bzimage] Support kernel command lines of greater than 256 characters
2.6.22+ kernels have an extra field in the bzimage_header structure to
indicate the maximum permitted command-line length. Use this if it is
available.
[ELF] Add ability to boot ELF images generated by wraplinux and mkelfImage
Delete ELF as a generic image type. The method for invoking an
ELF-based image (as well as any tables that must be set up to allow it
to boot) will always depend on the specific architecture. core/elf.c
now only provides the elf_load() function, to avoid duplicating
functionality between ELF-based image types.
Add arch/i386/image/elfboot.c, to handle the generic case of 32-bit
x86 ELF images. We don't currently set up any multiboot tables, ELF
notes, etc. This seems to be sufficient for loading kernels generated
using both wraplinux and coreboot's mkelfImage.
Note that while Etherboot 5.4 allowed ELF images to return, we don't.
There is no callback mechanism for the loaded image to shut down gPXE,
which means that we have to shut down before invoking the image. This
means that we lose device state, protection against being trampled on,
etc. It is not safe to continue afterwards.
Michael Brown