FDT overlays is de-facto standard for describing expansion boards like
Beaglebone capes or Raspberry Pi shields. The ides is to have basic
DTB for base board and overlays DTB for shields/capes and to construct
final DTB either using human-readable configuration or some
self-discovery mechanism. I believe this approach can also be expanded
to support dynamically loadable FPGA bitstreams on systems like
Zedboard/Zybo.
Overlaying process is simmilar to executable link process for
binaries: each DTB has "exported" symbols and "undefined" symbols, the
latter are resolved using information for the former obtained from
base DTB or one of the overlays applied earlier (more rare case).
This symbols information is not generated by standard dtc that FreeBSD
has in base system, patched[1] version required to produces
overlay-compatible blobs. So although DTB files generated by
buildkernel do not support overlays there are enough
vendor/community-provided DTB blobs ciruclating around to justify
committing this change to ubldr.
This commit introduces handler for "fdt_overlays" variable that can be
defined either as a loader env variable or U-Boot env variable.
fdt_overlays is comma-separated list of .dtbo files located in
/boot/dtb/ directory along with base .dtb. ubldr loads files and
applies them one-by-one to base .dtb and then passes result blob to
the kernel.
[1] dd6a0533e8
Differential Revision: https://reviews.freebsd.org/D3180
The block cache implementation in loader has proven to be almost useless, and in worst case even slowing down the disk reads due to insufficient cache size and extra memory copy.
Also the current cache implementation does not cache reads from CDs, or work with zfs built on top of multiple disks.
Instead of an LRU, this code uses a simple hash (O(1) read from cache), and instead of a single global cache, a separate cache per block device.
The cache also implements limited read-ahead to increase performance.
To simplify read ahead management, the read ahead will not wrap over bcache end, so in worst case, single block physical read will be performed to fill the last block in bcache.
Booting from a virtual CD over IPMI:
0ms latency, before: 27 second, after: 7 seconds
60ms latency, before: over 12 minutes, after: under 5 minutes.
Submitted by: Toomas Soome <tsoome@me.com>
Reviewed by: delphij (previous version), emaste (previous version)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D4713
Until now, ubldr has been trying to locate the U-Boot API using a hint
address (U-Boot's current stack pointer), aligning it to 1MiB and going
over a 3MiB (or 1MiB in case of MIPS) memory region searching for a
valid API signature.
This change introduces an alternative way of doing this, namely the
following:
- both U-Boot's bootelf and go commands actually pass argc and argv to
the entry point (e.g., ubldr's start function, but they should also
be passed over to main() transparently)
- so, instead of trying to go and look for a valid API signature, we
look at the parameters passed to main()
- if there's an option '-a' with argument, which is a valid hexadecimal
unsigned long number (x), we try to verify whether we have a valid
API signature at address x. If so - we use it. If not - we fallback
to the original way of locating the API signature.
The U-Boot change, which causes the API structure address to be
exported as an environment variable, was committed to mainline U-Boot
as commit 22aa61f707574dd569296f521fcfc46a05f51c48
Reviewed by: andrew, adrian
Approved by: adrian (mentor)
Sponsored by: Smartcom - Bulgaria AD
Differential Revision: https://reviews.freebsd.org/D5492
ubldr.
The changes are mostly dealing with removing unnecessary casts from the U-Boot
API (we're passing only pointers, no obvious reason to cast them to uint32_t),
cleaning up some compiler warnings and using the proper printf format
specifiers in order to be able to compile cleanly for both 32-bit and 64-bit
MIPS targets.
Reviewed by: imp
Approved by: adrian (mentor)
Sponsored by: Smartcom - Bulgaria AD
Differential Revision: https://reviews.freebsd.org/D5312
sys/boot/fdt/Makefile
sys/boot/uboot/fdt/Makefile
sys/boot/uboot/lib/Makefile
This causes compilation issues on MIPS due to trying to link PIC with non-PIC
code. This revision includes bsd.stand.mk in the above files.
Reviewed by: imp
Approved by: adrian (mentor)
Sponsored by: Smartcom - Bulgaria AD
Differential Revision: https://reviews.freebsd.org/D5311
import it into the loader(8) env as dhcp.root-path, so that it overrides
any dhcp/bootp server-provided path.
Now if you have a dhcp server available you can easily net-boot a u-boot
system even if you don't control the dhcp server config, by setting just
two variables in the u-boot env:
loaderdev=net
rootpath=<nfsserverip>:<pathname>
Previously you had to either accept all the dhcp parameters from the
server without the ability to locally provide the rootpath, or you had
to forego dhcp and set more vars (ipaddr, netmask, serverip, rootpath).
infinitely less buggy than code that is theoretically correct in some
alternate universe.
The uintfptr_t type is apparently a freebsd invention, and exists only when
compiling the kernel. It's a little hard to say for sure, since it doesn't
seem to be documented anywhere except in email advice to unsuspecting and
overly-trusting souls, who then get to wear the pointy hat for blindly
following advice without investigating or testing it first.
because rounding down cannot increase the number of bits needed to express
the result.
I had no idea there was such a thing as uintfptr_t.
Requested by: bde
a problem on 32-bit systems which have ram occupying the end of the physical
address space -- for example, a block of ram at 0x80000000 with a size of
0x80000000 was overflowing 32 bit math and ending up with a calculated size
of zero.
This is a fix for one of the two problems mentioned in the PR. Something
similar will need to be done on the kernel side before the PR is closed.
PR: 201614
empty ldvar (which amounts to the varname string starting with '=') into
the if block that manipulates ldvar, which avoids later referencing ldvar
when it was never initialized.
Submitted by: Thomas Skibo
Pointy hat: ian
directly into a loader (and thus kernel) env var, using the syntax
ubenv import ldvarname=ubvarname
Without the varname= prefix it uses the historical behavior of importing
to the name uboot.ubvarname.
No behavioral changes, just cosmetics.
A partition number of zero is not a wildcard, it's the 'a' partition in
a BSD slice, so don't print it as "<auto>". (Only slices are 1-based,
unit and partition numbers are 0-based and -1 is their wildcard marker.)
Also, after doing all the probing and choosing, print the final result as
"Booting from <disk spec>" where disk spec has all the wildcards resolved
and looks like familiar BSD slice-and-partition notation (disk0s3a, etc).
"fdt_file" and "fdtfile" U-Boot variables. Add one more check for
"fdt_file" loader(8) variable.
loader(8) variable takes precedence over u-boot env one
function, which is expected to set returned env to NULL upon reaching the end
of the environment list but fails to do so in certain cases. The respective
u-boot code looks like the following (HEAD at the time of this commit):
--- api.c ---
496 static int API_env_enum(va_list ap)
...
510 *next = last;
511
512 for (i = 0; env_get_char(i) != '\0'; i = n + 1) {
513 for (n = i; env_get_char(n) != '\0'; ++n) {
514 if (n >= CONFIG_ENV_SIZE) {
515 /* XXX shouldn't we set *next = NULL?? */
516 return 0;
517 }
518 }
-------------
The net result is that any unfortunate user of the loader's ub_env_enum()
function hitting this condition would be trapped in the infinite loop, as
the main use pattern of ub_env_enum() is basically the following:
while ((env = ub_env_enum(env)) != NULL) { DO STUFF }
Which would stuck forever with the last element.
fails to properly consider memory regions when the loader is
located below of those regions or engulfs their lower limit. This
results in "not enough RAM to load kernel" panic, which is totally
bogus. On top of that, there are some variables that can be left
unitialized in those cases, which might cause it fail with memory
access violation instead of panic while trying to load kernel to
a wrong or non-existing address of memory.
Augment the code to properly deal with the loader being below or
at the lower bound of the memory region in question. Also, don't
leave ununitialized variables behind.
Reviewed by: ian
it from the uboot net_init() implementation. The routine uses the standard
U-Boot env vars plus a freebsd-specific variable named "rootpath" (the
corresponding u-boot variable for that would be "bootfile" except that it
refers to ubldr, so a new name was needed to communicate the path to ubldr).
This allows ubldr to load a kernel from nfs without requiring a dhcp or
bootp server to provide the server ip and rootpath parameters.
Previously, ubldr would use the virtual addresses in the elf headers by
masking off the high bits and assuming the result was a physical address
where the kernel should be loaded. That would sometimes discard
significant bits of the physical address, but the effects of that were
undone by archsw copy code that would find a large block of memory and
apply an offset to the source/dest copy addresses. The result was that
things were loaded at a different physical address than requested by the
higher code layers, but that worked because other adjustments were applied
later (such as when jumping to the entry point). Very confusing, and
somewhat fragile.
Now the archsw copy routines are just simple copies, and instead
archsw.arch_loadaddr is implemented to choose a load address. The new
routine uses some of the code from the old offset-translation routine to
find the largest block of ram, but it excludes ubldr itself from that
range, and also excludes If ubldr splits the largest block of ram in
two, the kernel is loaded into the bottom of whichever resulting block is
larger.
As part of eliminating ubldr itself from the ram ranges, export the heap
start/end addresses in a pair of new global variables.
This change means that the virtual addresses in the arm kernel elf headers
now have no meaning at all, except for the entry point address. There is
an implicit assumption that the entry point is in the first text page, and
that the address in the the header can be turned into an offset by masking
it with PAGE_MASK. In the future we can link all arm kernels at a virtual
address of 0xC0000000 with no need to use any low-order part of the
address to influence where in ram the kernel gets loaded.
several types of data into the mem-info array (DRAM, SRAM, flash). We
need to extract just the DRAM entries for translation into fdt memory
properties.
Also, increase the number of regions we can handle from 5 to 16.
Submitted by: Michal Meloun
moving U-Boot specific code from libfdt.a to a new libuboot_fdt.a. This
needs to be a new library for linking to work correctly.
Differential Revision: https://reviews.freebsd.org/D1054
Reviewed by: ian, rpaulo (earlier version)
MFC after: 1 week
u-boot env into the loader(8) env (which also gets them into the kernel
env). You can import selected variables or the whole environment. Each
u-boot var=value becomes uboot.var=value in the loader env. You can also
use 'ubenv show' to display uboot vars without importing them.
particular, allow loaders to define the name of the RC script the
interpreter needs to use. Use this new-found control to have the
PXE loader (when compiled with TFTP support and not NFS support)
read from ${bootfile}.4th, where ${bootfile} is the name of the
file fetched by the PXE firmware.
The normal startup process involves reading the following files:
1. /boot/boot.4th
2. /boot/loader.rc or alternatively /boot/boot.conf
When these come from a FreeBSD-defined file system, this is all
good. But when we boot over the network, subdirectories and fixed
file names are often painful to administrators and there's really
no way for them to change the behaviour of the loader.
Obtained from: Juniper Networks, Inc.
- Display slice and partition as <auto> instead of 0 or -1 when they're
not set to specific values (the paritition=-1 was confusing folks).
- When loaderdev isn't set in the u-boot environment, say so rather
than displaying unknown device ''.
- Print the loader(8) ident/version info earlier, so that all device-
related info appears together afterwards.
The one change here that isn't purely cosmetic is to call setheap()
earlier. The comment says "Initialise heap as early as possible", now
that's more accurate. It shouldn't make any functional difference, but
may be safer if future changes lead to trying to allocate memory earlier.
setting the u-boot environment variable loaderdev=. It used to accept only
'disk' or 'net'. Now it allows specification of unit, slice, and partition
as well. In addition to the generic 'disk' it also accepts specific
storage device types such as 'mmc' or 'sata'.
If there isn't a loaderdev env var, the historical behavior is maintained.
It will use the first storage device it finds, or a network device if
no working storage device exists.
99% of the work on this was done by Patrick Kelsey, but I made some
changes, so if anything goes wrong, blame me.
Submitted by: Patrick Kelsey <kelsey@ieee.org>
by having uboot_autoload() do the fdt setup (which may load a file) rather
than waiting until we're actually in the process of launching the kernel.
As part of making this happen...
- Define LOADER_FDT_SUPPORT on the uboot/lib compile command line when
MK_FDT is set.
- Make fdt_setup_fdtb() public.
- Declare public fdt_whatever() functions in a header instead of using
scattered extern decls in .c files.
If a "loaderdev=<device>" env variable is set and the named device
exists, it is used. If the device doesn't exist, fall back to the
historic "probe" loop that prefers disk devices over network devices.
If the env var is not set, preserve the historic behavior of using the
first working disk device provided by u-boot, or a network device if no
functional disk device is found and a network device exists.
The old probe loop is reworked so that it checks all bootable devices
provided by u-boot rather than taking an early-out on the first device
found. This results in the cosmetic change of listing all potential boot
devices for the user, but the behavior of which device it chooses is the
same as it has always been.
- Add "fdt addr" subcommand that lets you specify preloaded blob address
- Do not pre-initialize blob for "fdt addr"
- Do not try to load dtb every time fdt subcommand is issued,
do it only once
- Change the way DTB is passed to kernel. With introduction of "fdt addr"
actual blob address can be not virtual but physical or reside in
area higher then 64Mb. ubldr should create copy of it in kernel area
and pass pointer to this newly allocated buffer which is guaranteed to work
in kernel after switching on MMU.
- Convert memreserv FDT info to "memreserv" property of root node
FDT uses /memreserve/ data to notify OS about reserved memory areas.
Technically it's not real property, it's just data blob, sequence
of <start, size> pairs where both start and size are 64-bit integers.
It doesn't fit nicely with OF API we use in kernel, so in order to unify
thing ubldr converts this data to "memreserve" property using the same
format for addresses and sizes as /memory node.
disk_open(). Very often this is called several times for one file.
This leads to reading partition table metadata for each call. To
reduce the number of disk I/O we have a simple block cache, but it
is very dumb and more than half of I/O operations related to reading
metadata, misses this cache.
Introduce new cache layer to resolve this problem. It is independent
and doesn't need initialization like bcache, and will work by default
for all loaders which use the new DISK API. A successful disk_open()
call to each new disk or partition produces new entry in the cache.
Even more, when disk was already open, now opening of any nested
partitions does not require reading top level partition table.
So, if without this cache, partition table metadata was read around
20-50 times during boot, now it reads only once. This affects the booting
from GPT and MBR from the UFS.
