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.
Removed REAL_FRAGMENT and REAL_CALL, and left just REAL_EXEC (which is
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.).
Refactored to reduce code size; now down from 1304 to 1105 bytes.
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)
Add the concept of a "user pointer" (similar to the void __user * in
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).
Strip down i386 PCI configuration space I/O to the bare minimum. A
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.)
Restructured PCI subsystem to fit the new device model.
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).