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.
The generic ELF loading code maps the kernel into low memory
by subtracting KERN_BASE. So the copyin/copyout/readin functions
are always called with low addresses. This code finds the largest
DRAM block from the U-Boot memory map and adds that base to
the addresses.
In particular, this fixes ubldr on AM3358, which has DRAM
mapped to 0x80000000 at power-on.
The code previously assumed that copyin/copyout did no
address translation and that the device tree blob could
be manipulated in-place (with only a few adjustments for
the ELF loader offset). This isn't possible on all platforms,
so the revised code uses copyout() to copy the device tree
blob into a heap-allocated buffer and then updates the
device tree with copyout(). This isn't ideal, since it
bloats the loader memory usage, but seems the only feasible
approach (short of rewriting all of the fdt manipulation
routines).
