[SeaBIOS] [RFC 0/3] NVDIMM booting support

[Marc Marí]

Implement support for booting from a PMEM region compatible with NVDIMM and
NFIT specifications.

The current implementation is still slow. When running a Linux guest on top of
QEMU in x86:

Using actual -kernel option:
QEMU startup time: .080
BIOS startup time: .060
Kernel setup time: .590
Total time: .730

Using -kernel option and fw_cfg DMA patch:
QEMU startup time: .080
BIOS startup time: .039
Kernel setup time: .002
Total time: .121

Using this patch series and adding the vmlinuz as a NVDIMM device:
QEMU startup time: .080
BIOS startup time: .065
Kernel setup time: .015
Total time: .160

This patch series is not ready for merging. There are things missing and
questions to be answered:
 - Is it necessary to retrieve any other data from the NVDIMM?
 - Is there any other nicer (and faster) option for the page table?
 - Make NVDIMM a compile-time option, as the other devices.
 - Add some kind of wrapper to the boot files instead of a direct vmlinux.
 - Add NVDIMM boot priority support.
 - Add support for intitrd and cmdline. Maybe in another NVDIMM, or in the
   same, or through fw_cfg.
 - Reorder code to change to long mode less times.

Any other proposals for improvements are appreciated

Marc Marí (3):
  Basic NVDIMM PMEM support
  Transitions to and from 64 bits
  Add NVDIMM booting support

 Makefile            |   3 +-
 src/boot.c          |  18 ++++++++
 src/config.h        |   2 +
 src/fw/biostables.c |  80 ++++++++++++++++++++++++++++++++
 src/hw/nvdimm.c     | 128 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/hw/nvdimm.h     |  12 +++++
 src/misc.c          |   4 ++
 src/post.c          |   2 +
 src/romlayout.S     | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/stacks.c        |  77 +++++++++++++++++++++++++++++++
 src/stacks.h        |   2 +
 src/std/acpi.h      |  40 ++++++++++++++++
 src/util.h          |   3 ++
 src/x86.h           |   1 +
 14 files changed, 497 insertions(+), 1 deletion(-)
 create mode 100644 src/hw/nvdimm.c
 create mode 100644 src/hw/nvdimm.h

-- 
2.4.3