real_call(), rather than moving it to the RM stack and back again.
This allows the real-mode function to completely destroy the stack
contents, provided that it manages to return to real_call().
UNDI ROM code etc. when you just want a "undi.kpxe"-type image).
This driver cannot be used in conjunction with any other driver (it will
crash), or in any other format than .kpxe (it just won't find any network
devices).
memory (unless we get an error while stopping the base code). Leave UNDI
resident (though stopped) for .kpxe.
Still need to add code to record the device identification parameters
prior to stopping UNDI.
function prefix "undinet_" and the variable name "undinic" in undinet.c,
so that we can reserve the variable name "undi" for a struct undi_device.
The idea is that we preserve the Etherboot 5.4 convention that the "UNDI"
code refers to our using an underlying UNDI stack, while the "PXE" code
refers to our providing a PXE API.
UNDI_GET_INFORMATION calls into drivers/net/undi.c. undi_probe() now
gets given a pxe_device representing a PXE stack that has been loaded
into memory but not initialised in any way.
causing the serial console to ignore input, because it happened to end up
linked with serial_ischar() at address 0, which core/console.c decided was
invalid).
technically be necessary, because the "enable A20" command requires
only that the keyboard controller is ready to accept input (i.e. that
its input buffer is empty), and shouldn't also require that the
keyboard is ready to send output (i.e. that its output buffer is also
empty). See http://www.smsc.com/main/tools/io-bios/42i.pdf section
3.1 ("Command Invocation") for a justification.
gateA20_set() is called on every real-mode transition (in case some
idiot piece of external code such as Intel's PXE stack decided it
would be fun to re-disable A20), so draining the keyboard buffer means
that we end up losing keypresses on some systems. In particular, this
makes typing at the command line almost impossible, and causes
Etherboot to ignore Ctrl-Alt-Del.
We should really implement a gateA20_test() function to verify that
gate A20 has been correctly enabled, and think about adding other
commonly-used methods such as Fast Gate A20.
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.
skip past an empty region, otherwise we end up generating an infinitely
long e820 map. (Yes, there *are* real systems that provide e820 maps
with a zero-length region at the end...)
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.)
Allow our functions to return a non-zero, non-error status (since the
INT 13 Extensions Check has to return the API version in the register
that is otherwise always used for the error code).
Report a non-zero API version from the INT 13 Extensions Check; GRUB
now uses extended reads.
Change semantics; relocate() now just finds a suitable location; it
doesn't actually perform the relocation itself. Code in libprefix does
the copy in flat real mode.
the only one we actually use). This allows REAL_EXEC fragments to
contain proper references to constraints (e.g. "%w0"), rather than having
to force the use of specific registers.
Note that the "num_constraints" parameter is now completely obsolete, and
that we can probably reduce the syntax to something like
__asm__ __volatile__ ( REAL_CODE ( "asm statements" )
: output constraints
: input constraints
: clobber );
which would look much more natural, and avoid the need to always specify
a clobber list.
Add userptr_t to libkir.h, to allow it to at least compile.
We now split e820 regions around ourselves, rather than just
truncating the e820 region. This avoids the worst-case scenario of
losing all memory over 4GB.
It's more important to get the memory map right now that we're
expecting to still be loaded when the OS starts in several situations
(e.g. Linux with UNDI driver, any OS with iSCSI/AoE boot, etc.).
Tidied up debug messages; the log now contains one line per INT 13
operation, looking like
INT 13,08 (80): Get drive parameters
INT 13,02 (80): Read: C/H/S 0/47/14 = LBA 0xb9e <-> 1084:0000 (count 106)
the kernel), which encapsulates the information needed to refer to an
external buffer. Under normal operation, this can just be a void *
equivalent, but under -DKEEP_IT_REAL it would be a segoff_t equivalent.
Use this concept to avoid the need for bounce buffers in int13.c,
which reduces memory usage and opens up the possibility of using
multi-sector reads.
Extend the block-device API and the SCSI block device implementation
to support multi-sector reads.
Update iscsi.c to use user buffers.
Move the obsolete portions of realmode.h to old_realmode.h.
MS-DOS now boots an order of magnitude faster over iSCSI (~10 seconds
from power-up to C:> prompt in bochs).
typical build will now include 880 bytes of PCI support code, compared to
2327 bytes in Etherboot 5.4.
(There is a slight cost of around 5 extra bytes per access to a
non-constant config space address; this should be an overall win.
Driver-specific accesses will usually be to constant addresses, for
which there is no additional cost.)
Generic PCI code now handles 64-bit BARs correctly when setting
"membase"; drivers should need to call pci_bar_start() only if they want
to use BARs other than the first memory or I/O BAR.
Split rarely-used PCI functions out into pciextra.c.
Core PCI code is now 662 bytes (down from 1308 bytes in Etherboot 5.4).
284 bytes of this saving comes from the pci/pciextra split.
Cosmetic changes to lots of drivers (e.g. vendor_id->vendor in order to
match the names used in Linux).
Use .text16.data section with "aw" attributes, to avoid section type
conflicts when placing both code and data into .text16.
Add __from_{text16,data16}.
between the low half stored in the static variable rm_sp, and the high
half stored on the prot_call() stack, because:
Just using the stack would screw up when a prot_call()ed routine
executes a real_call(); it would have no way to find the current top of
the RM stack.
Extending rm_sp to rm_esp would not be safe, because the guarantee that
rm_sp must return to the correct value by the time an external
real-mode call returns applies only to %sp, not to %esp.
from protected-mode code.
Set up %ds to point to .data16 in prot_to_real, so that code specified
via REAL_EXEC() and friends can access variables in .data16.
Move most real-mode librm variables from .text16 to .data16.