[romprefix] Allow BANNER_TIMEOUT to control banners in romprefix.S
In particular, allow BANNER_TIMEOUT=0 to inhibit the prompt banners
altogether.
Ironically, this request comes from the same OEM that originally
required the prompts to be present during POST.
[romprefix] If we hook INT 19, prompt before attempting boot
On non-BBS systems we hook INT 19, since there is no other way we can
guarantee gaining control of the flow of execution. If we end up
doing this, prompt the user before attempting boot, since forcibly
capturing INT 19 is rather antisocial.
[libprefix] Add addr32 prefix required by older assemblers
Explicitly state that we are using 32-bit addressing in 16-bit code.
GNU as 2.15 (FreeBSD/amd64 7-STABLE) got confused that 32-bit registers
are used in the code that was declared as 16-bit. Add explicit modifier
'addr32' to make assembler happy.
Signed-off-by: Eygene Ryabinkin <rea-fbsd@codelabs.ru>
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.
[romprefix] Add more diagnostic messages to ROM prefix
Include PMM allocation result in POST banner.
Include full product string in "starting execution" message.
Also mark ourselves as supporting DDIM in PnP header, for
completeness.
[romprefix] On a PCI3.0, non-BBS system, use the correct %cs for INT19
On a system that doesn't support BBS, we end up hooking INT19 to gain
control of the boot process. If the system is PCI3.0, we must take
care to use the runtime value for %cs, rather than the POST-time
value, otherwise we end up pointing INT19 to the temporary option ROM
POST scratch area.
[prefix] Reasonable value for lkrn initrd_addr_max
H. Peter Anvin <hpa@zytor.com> sent word that Sergey Vlasov
<vsu@altlinux.ru> discovered gPXE lkrn images fail to load in SYSLINUX
3.70 because we have initrd_addr_max zeroed. This patch sets the same
value as the Linux kernel.
Also change the header jmp instruction to use a hardcoded opcode value
like Linux does. Just in case the assembler decides to use a three-byte
instruction instead of the desired two-byte jmp.
Commit fd0aef9 introduced a typo that caused PMM detection to start at
paragraph 0xe00 rather than 0xe000. (Detection would still work, since it
would scan until it ran out of base memory, but it would end up scanning
an unnecessarily large portion of base memory.)
Spotted by Sebastian Herbszt <herbszt@gmx.de>.
[prefix] When we have to hook INT 19, chain to original handler if possible
When the BIOS doesn't support BBS, hooking INT 19 is the only way to add
ourselves as a boot device. If we have to do this, we should at least
try to chain to the original INT 19 vector if our boot fails.
Idea suggested by Andrew Schran <aschran@google.com>
[prefix] Prompt for entering gPXE shell during POST
The ROM prefix now prompts the user to enter the gPXE shell during POST;
this allows for configuring gPXE without needing to attempt to boot from
it. (It also slows down system boot by three seconds per gPXE ROM, but
hey.)
This is apparently a certain OEM's requirement for option ROMs.
[prefix] Cope with image source addresses outside base memory
When PMM is used, the gPXE image source will no longer be in base memory.
Decompression of .text16 and .data16 can therefore no longer be done in
real mode.
Use BBS installation check to see if we need to hook INT19 even on a PnP
BIOS.
Verify that $PnP signature is paragraph-aligned; bochs/qemu BIOS provides
a dummy $PnP signature with no valid entry point, and deliberately
unaligns the signature to indicate that it is not properly valid.
Print message if INT19 is hooked.
Attempt to use PMM even if BBS check failed.
ROM initialisation vector now attempts to allocate a 2MB block using
PMM. If successful, it copies the ROM image to this block, then
shrinks the ROM image to allow for more option ROMs. If unsuccessful,
it leaves the ROM as-is.
ROM BEV now attempts to return to the BIOS, resorting to INT 18 only
if the BIOS stack has been corrupted.
Don't trash the %ecx value returned by relocate(). This was causing
us to round down the size for the relocation copy to the nearest 64kB
(+0x10 bytes); this just happened to work on most machines because the
last 64kB of the image is all-zeroes anyway (it's the .bss).
Michael Brown