Add support for Pre-Boot Virtual Memory (PBVM) to the loader.
PBVM allows us to link the kernel at a fixed virtual address without
having to make any assumptions about the physical memory layout. On
the SGI Altix 350 for example, there's no usuable physical memory
below 192GB. Also, the PBVM allows us to control better where we're
going to physically load the kernel and its modules so that we can
make sure we load the kernel in memory that's close to the BSP.
The PBVM is managed by a simple page table. The minimum size of the
page table is 4KB (EFI page size) and the maximum is currently set
to 1MB. A page in the PBVM is 64KB, as that's the maximum alignment
one can specify in a linker script. The bottom line is that PBVM is
between 64KB and 8GB in size.
The loader maps the PBVM page table at a fixed virtual address and
using a single translations. The PBVM itself is also mapped using a
single translation for a maximum of 32MB.
While here, increase the heap in the EFI loader from 512KB to 2MB
and set the stage for supporting relocatable modules.
sizes are not supported.
o Map the PBVM page table.
o Map the PBVM using the largest possible power of 2 that is less than
the amount of PBVM used and round down to a valid page size. Note
that the current kernel is between 8MB and 16MB in size, which would
mean that 8MB would be the typical size of the mapping, if only 8MB
wasn't an invalid page size. In practice, we end up mapping the first
4MB of PBVM in most cases.
between kernel virtual address and physical address anymore. This so
that we can link the kernel at some virtual address without having
to worry whether the corresponding physical memory exists and is
available. The PBVM uses 64KB pages that are mapped to physical
addresses using a page table. The page table is at least 1 EFI page
in size, but can grow up to 1MB. This effectively gives us a memory
size between 32MB and 8GB -- i.e. enough to load a DVD image if one
wants to.
The loader assigns physical memory based on the EFI memory map and
makes sure that all physical memory is naturally aligned and a power
of 2. At this time there's no consideration for allocating physical
memory that is close to the BSP.
The kernel is informed about the physical address of the page table
and its size and can locate all PBVM pages through it.
The loader does not wire the PBVM page table yet. Instead it wires
all of the PBVM with a single translation. This is fine for now,
but a follow-up commit will fix it. We cannot handle more than 32MB
right now.
Note that the loader will map as much of the loaded kernel and
modules as possible, but it's up to the kernel to handle page faults
for references that aren't mapped. To make that easier, the page
table is mapped at a fixed virtual address.
o bunch of variables are turned into uint8_t
o initial setting of namep[] in lookup() is removed
as it's only overwritten a few lines down
o kname is explicitly initialized in main() as BSS
in boot2 is not zeroed
o the setting and reading of "fmt" in load() is removed
o buf in printf() is made static to save space
Reviewed by: jhb
Tested by: me and Fabian Keil <freebsd-listen fabiankeil de>
This patch shrinks boot2 a little.
o It switches kname to be just a pointer instead of an array.
o It changes ioctl to unsigned from uint8_t.
o It changes the second keyhit limit to 3 seconds from 5.
o It removes bi_basemem/bi_extmem/bi_memsizes_valid setting.
o It switches kname to be just a pointer instead of an array
thus avoiding a couple of memcpy()s.
o It changes ioctl to unsigned from uint8_t.
o It changes the second keyhit limit to 3 seconds from 5
so that constant propagation can take place.
o It changes the ticks overflow computation as suggested by bde@.
o It removes bi_basemem/bi_extmem/bi_memsizes_valid setting from
bootinfo as it is unused.
Reviewed by: jhb
Few new things available from now on:
- Data deduplication.
- Triple parity RAIDZ (RAIDZ3).
- zfs diff.
- zpool split.
- Snapshot holds.
- zpool import -F. Allows to rewind corrupted pool to earlier
transaction group.
- Possibility to import pool in read-only mode.
MFC after: 1 month
It used to choke on the notation "inb (%dx),%al" for "inb %dx,%al"; GNU
as accepts both forms. Which notation is more 'correct' is an open
question. :)
In sys/boot/i386/boot2/boot2.c, change the type of the 'opts' variable
from uint16_t back to uint32_t. The actual option bitmasks (RB_* and
RBX_*) assume at least a 32 bit variable.
Submitted by: rdivacky
x86 CPU support, better support for powerpc64, some new directives, and
many other things. Bump __FreeBSD_version, and add a note to UPDATING.
Thanks to the many people that have helped to test this.
Obtained from: projects/binutils-2.17
on space for clang and a.out support is only needed for /boot/loader,
they are excess bytes that serve no useful purpose other than to
support really old kernels (FreeBSD < 3.2 or so). Prefer clang
support over support for these old kernels and remove this code. We
gain about 100 bytes of space this way.
Reviewed by: rdivacky@
little further. This gets us further on the way to be able to build it
successfully with clang. Using in-tree gcc, this shrinks boot2.bin with
60 bytes, the in-tree clang shaves off 72 bytes, and ToT clang 84 bytes.
Submitted by: rdivacky
Reviewed by: imp
available on firmwares 3.15 and earlier.
Caveats: Support for the internal SATA controller is currently missing,
as is support for framebuffer resolutions other than 720x480. These
deficiencies will be remedied soon.
Special thanks to Peter Grehan for providing the hardware that made this
port possible, and thanks to Geoff Levand of Sony Computer Entertainment
for advice on the LV1 hypervisor.
