grub_xnu_devprop_add_property() should not free utf8 and utf16 as it get
allocated and freed in the caller.
Minor improvement: do prop fields initialization after memory allocations.
Fixes: CID 292442, CID 292457, CID 292460, CID 292466
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This attempts to fix the places where we do the following where
arithmetic_expr may include unvalidated data:
X = grub_malloc(arithmetic_expr);
It accomplishes this by doing the arithmetic ahead of time using grub_add(),
grub_sub(), grub_mul() and testing for overflow before proceeding.
Among other issues, this fixes:
- allocation of integer overflow in grub_video_bitmap_create()
reported by Chris Coulson,
- allocation of integer overflow in grub_png_decode_image_header()
reported by Chris Coulson,
- allocation of integer overflow in grub_squash_read_symlink()
reported by Chris Coulson,
- allocation of integer overflow in grub_ext2_read_symlink()
reported by Chris Coulson,
- allocation of integer overflow in read_section_as_string()
reported by Chris Coulson.
Fixes: CVE-2020-14309, CVE-2020-14310, CVE-2020-14311
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This modifies most of the places we do some form of:
X = malloc(Y * Z);
to use calloc(Y, Z) instead.
Among other issues, this fixes:
- allocation of integer overflow in grub_png_decode_image_header()
reported by Chris Coulson,
- allocation of integer overflow in luks_recover_key()
reported by Chris Coulson,
- allocation of integer overflow in grub_lvm_detect()
reported by Chris Coulson.
Fixes: CVE-2020-14308
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Currently the string functions grub_strtol(), grub_strtoul(), and
grub_strtoull() don't declare the "end" pointer in such a way as to
require the pointer itself or the character array to be immutable to the
implementation, nor does the C standard do so in its similar functions,
though it does require us not to change any of it.
The typical declarations of these functions follow this pattern:
long
strtol(const char * restrict nptr, char ** restrict endptr, int base);
Much of the reason for this is historic, and a discussion of that
follows below, after the explanation of this change. (GRUB currently
does not include the "restrict" qualifiers, and we name the arguments a
bit differently.)
The implementation is semantically required to treat the character array
as immutable, but such accidental modifications aren't stopped by the
compiler, and the semantics for both the callers and the implementation
of these functions are sometimes also helped by adding that requirement.
This patch changes these declarations to follow this pattern instead:
long
strtol(const char * restrict nptr,
const char ** const restrict endptr,
int base);
This means that if any modification to these functions accidentally
introduces either an errant modification to the underlying character
array, or an accidental assignment to endptr rather than *endptr, the
compiler should generate an error. (The two uses of "restrict" in this
case basically mean strtol() isn't allowed to modify the character array
by going through *endptr, and endptr isn't allowed to point inside the
array.)
It also means the typical use case changes to:
char *s = ...;
const char *end;
long l;
l = strtol(s, &end, 10);
Or even:
const char *p = str;
while (p && *p) {
long l = strtol(p, &p, 10);
...
}
This fixes 26 places where we discard our attempts at treating the data
safely by doing:
const char *p = str;
long l;
l = strtol(p, (char **)&ptr, 10);
It also adds 5 places where we do:
char *p = str;
while (p && *p) {
long l = strtol(p, (const char ** const)&p, 10);
...
/* more calls that need p not to be pointer-to-const */
}
While moderately distasteful, this is a better problem to have.
With one minor exception, I have tested that all of this compiles
without relevant warnings or errors, and that /much/ of it behaves
correctly, with gcc 9 using 'gcc -W -Wall -Wextra'. The one exception
is the changes in grub-core/osdep/aros/hostdisk.c , which I have no idea
how to build.
Because the C standard defined type-qualifiers in a way that can be
confusing, in the past there's been a slow but fairly regular stream of
churn within our patches, which add and remove the const qualifier in many
of the users of these functions. This change should help avoid that in
the future, and in order to help ensure this, I've added an explanation
in misc.h so that when someone does get a compiler warning about a type
error, they have the fix at hand.
The reason we don't have "const" in these calls in the standard is
purely anachronistic: C78 (de facto) did not have type qualifiers in the
syntax, and the "const" type qualifier was added for C89 (I think; it
may have been later). strtol() appears to date from 4.3BSD in 1986,
which means it could not be added to those functions in the standard
without breaking compatibility, which is usually avoided.
The syntax chosen for type qualifiers is what has led to the churn
regarding usage of const, and is especially confusing on string
functions due to the lack of a string type. Quoting from C99, the
syntax is:
declarator:
pointer[opt] direct-declarator
direct-declarator:
identifier
( declarator )
direct-declarator [ type-qualifier-list[opt] assignment-expression[opt] ]
...
direct-declarator [ type-qualifier-list[opt] * ]
...
pointer:
* type-qualifier-list[opt]
* type-qualifier-list[opt] pointer
type-qualifier-list:
type-qualifier
type-qualifier-list type-qualifier
...
type-qualifier:
const
restrict
volatile
So the examples go like:
const char foo; // immutable object
const char *foo; // mutable pointer to object
char * const foo; // immutable pointer to mutable object
const char * const foo; // immutable pointer to immutable object
const char const * const foo; // XXX extra const keyword in the middle
const char * const * const foo; // immutable pointer to immutable
// pointer to immutable object
const char ** const foo; // immutable pointer to mutable pointer
// to immutable object
Making const left-associative for * and right-associative for everything
else may not have been the best choice ever, but here we are, and the
inevitable result is people using trying to use const (as they should!),
putting it at the wrong place, fighting with the compiler for a bit, and
then either removing it or typecasting something in a bad way. I won't
go into describing restrict, but its syntax has exactly the same issue
as with const.
Anyway, the last example above actually represents the *behavior* that's
required of strtol()-like functions, so that's our choice for the "end"
pointer.
Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
In some cases GRUB2 allocates multiboot2 structure at 0 address, that is
a confusing behavior. Consumers of that structure can have internal NULL-checks
that will throw an error when get a pointer to data allocated at address 0.
To prevent that, define min address for mbi allocation on x86 and x86_64
platforms.
Signed-off-by: Lukasz Hawrylko <lukasz.hawrylko@linux.intel.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Recent work around x86 Linux kernel loader revealed an underflow in the
setup_header length calculation and another related issue. Both lead to
the memory overwrite and later machine crash.
Currently when the GRUB copies the setup_header into the linux_params
(struct boot_params, traditionally known as "zero page") it assumes the
setup_header size as sizeof(linux_i386_kernel_header/lh). This is
incorrect. It should use the value calculated accordingly to the Linux
kernel boot protocol. Otherwise in case of pretty old kernel, to be
exact Linux kernel boot protocol, the GRUB may write more into
linux_params than it was expected to. Fortunately this is not very big
issue. Though it has to be fixed. However, there is also an underflow
which is grave. It happens when
sizeof(linux_i386_kernel_header/lh) > "real size of the setup_header".
Then len value wraps around and grub_file_read() reads whole kernel into
the linux_params overwriting memory past it. This leads to the GRUB
memory allocator breakage and finally to its crash during boot.
The patch fixes both issues. Additionally, it moves the code not related to
grub_memset(linux_params)/grub_memcpy(linux_params)/grub_file_read(linux_params)
section outside of it to not confuse the reader.
Fixes: e683cfb0cf (loader/i386/linux: Calculate the setup_header length)
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Krystian Hebel <krystian.hebel@3mdeb.com>
The address of fp->path_name could be unaligned since seeking into the
device path buffer for a given node could end in byte boundary.
The fix is using aligned buffer allocated by grub_malloc for receiving
the converted UTF16 string by grub_utf8_to_utf16 and also the processing
after. The resulting string then gets copied to fp->path_name.
[ 243s] ../../grub-core/loader/efi/chainloader.c: In function 'copy_file_path':
[ 243s] ../../grub-core/loader/efi/chainloader.c:136:32: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[ 243s] 136 | size = grub_utf8_to_utf16 (fp->path_name, len * GRUB_MAX_UTF16_PER_UTF8,
[ 243s] | ~~^~~~~~~~~~~
[ 243s] ../../grub-core/loader/efi/chainloader.c:138:12: error: taking address of packed member of 'struct grub_efi_file_path_device_path' may result in an unaligned pointer value [-Werror=address-of-packed-member]
[ 243s] 138 | for (p = fp->path_name; p < fp->path_name + size; p++)
[ 243s] | ^~
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Previously the setup_header length was just assumed to be the size of the
linux_kernel_params struct. The linux x86 32-bit boot protocol says that the
end of the linux_i386_kernel_header is at 0x202 + the byte value at 0x201 in
the linux_i386_kernel_header. So, calculate the size of the header using the
end of the linux_i386_kernel_header, rather than assume it is the size of the
linux_kernel_params struct.
Additionally, add some required members to the linux_kernel_params
struct and align the content of linux_i386_kernel_header struct with
it. New members naming was taken directly from Linux kernel source.
linux_kernel_params and linux_i386_kernel_header structs require more
cleanup. However, this is not urgent, so, let's do this after release.
Just in case...
Signed-off-by: Andrew Jeddeloh <andrew.jeddeloh@coreos.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@google.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
MIPS fallout cleanup after commit 4d4a8c96e (verifiers: Add possibility
to verify kernel and modules command lines).
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
PowerPC fallout cleanup after commit 4d4a8c96e (verifiers: Add possibility
to verify kernel and modules command lines) and ca0a4f689 (verifiers: File
type for fine-grained signature-verification controlling).
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
IA-64 fallout cleanup after commit 4d4a8c96e (verifiers: Add possibility
to verify kernel and modules command lines).
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Mirror behaviour of ELF loader in libxc: first look for Xen notes in
PT_NOTE segment, then in SHT_NOTE section and only then fallback to
a section with __xen_guest name. This fixes loading PV kernels that
Xen note have outside of PT_NOTE. While this may be result of a buggy
linker script, loading such kernel directly works fine, so make it work
with GRUB too. Specifically, this applies to binaries built from Unikraft.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
We currently only support to run grub on RISC-V as UEFI payload. Ideally,
we also only want to support running Linux underneath as UEFI payload.
Prepare that with some Linux boot stub code. Once the arm64 target is
generalized, we can hook into that one and gain boot functionality.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Some architectures want to boot Linux as plain UEFI binary. Today that
really only encompasses ARM and AArch64, but going forward more
architectures may adopt that model.
So rename our internal API accordingly.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This patch allows to have bigger kernels. If the kernel grows, then it will
overwrite the initrd when it is extracted.
Signed-off-by: Guillaume GARDET <guillaume.gardet@arm.com>
Acked-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
A certain amount of dynamic space is required for the handover from
GRUB/Linux-EFI-stub. This entails things like initrd addresses,
address-cells entries and associated strings.
But move this into a proper centralised #define rather than live-code
it in the loader.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
We should not try to copy any memory area which is outside of the original
fdt. If this extra memory is controlled by a hypervisor this might end
with a crash.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add the hooks to current code needed for Xen PVH. They will be filled
with code later when the related functionality is being added.
loader/i386/linux.c needs to include machine/kernel.h now as it needs
to get GRUB_KERNEL_USE_RSDP_ADDR from there. This in turn requires to
add an empty kernel.h header for some i386 platforms (efi, coreboot,
ieee1275, xen) and for x86_64 efi.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
Xen PVH guests will have the RSDP at an arbitrary address. Support that
by passing the RSDP address via the boot parameters to Linux.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
ARM Xen fallout cleanup after commit ca0a4f689 (verifiers: File type for
fine-grained signature-verification controlling).
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Xen fallout cleanup after commit ca0a4f689 (verifiers: File type for
fine-grained signature-verification controlling).
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Without this fix, building xen_boot.c omits:
loader/arm64/xen_boot.c: In function ‘xen_boot_binary_load’:
loader/arm64/xen_boot.c:370:7: error: too few arguments to function ‘grub_create_loader_cmdline’
grub_create_loader_cmdline (argc - 1, argv + 1, binary->cmdline,
^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from loader/arm64/xen_boot.c:36:0:
../include/grub/lib/cmdline.h:29:12: note: declared here
grub_err_t grub_create_loader_cmdline (int argc, char *argv[], char *buf,
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The verifiers framework changed the grub_file_open() interface, breaking all
non-x86 linux loaders. Add file types to the grub_file_open() calls to make
them build again.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The verifiers framework changed the API of grub_file_open(), but did not
fix up all users. Add the file type GRUB_FILE_TYPE_DEVICE_TREE_IMAGE
to the "devicetree" command handler call.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Let's provide file type info to the I/O layer. This way verifiers
framework and its users will be able to differentiate files and verify
only required ones.
This is preparatory patch.
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
1. move relocator related code more close to each other
2. use variable "len" since it has correct assignment, and keep coding
style with upper code
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Delete local copy of function to determine required buffer size for the
UEFI memory map, use helper in kern/efi/mm.c.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Delete local copy of function to determine required buffer size for the
UEFI memory map, use helper in kern/efi/mm.c.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Delete local copy of function to determine required buffer size for the
UEFI memory map, use helper in kern/efi/mm.c.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The 32-bit arm Linux kernel is built as a zImage, which self-decompresses
down to near start of RAM. In order for an initrd/initramfs to be
accessible, it needs to be placed within the first ~768MB of RAM.
The initrd loader built into the kernel EFI stub restricts this down to
512MB for simplicity - so enable the same restriction in grub.
For arm64, the requirement is within a 1GB aligned 32GB window also
covering the (runtime) kernel image. Since the EFI stub loader itself
will attempt to relocate to near start of RAM, force initrd to be loaded
completely within the first 32GB of RAM.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The 32-bit arm efi port now shares the 64-bit linux loader, so delete
the now unused bits from the 32-bit linux loader.
This in turn leaves the grub-core/kern/arm/efi/misc.c unused, so
delete that too.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
In preparation for using the linux loader for 32-bit and 64-bit platforms,
rename grub_arm64*/GRUB_ARM64* to grub_armxx*/GRUB_ARMXX*.
Move prototypes for now-common functions to efi/efi.h.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The EFI Graphics Output Protocol can return a 64-bit
linear frame buffer address in some firmware/BIOS
implementations. We currently only store the lower
32-bits in the lfb_base. This will eventually be
passed to Linux kernel and the efifb driver will
incorrectly interpret the framebuffer address as
32-bit address.
The Linux kernel has already added support to handle
64-bit linear framebuffer address in the efifb driver
since quite some time now.
This patch adds the support for 64-bit linear frame
buffer address in GRUB to address the above mentioned
scenario.
Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Without that fix we have:
In file included from ../../include/grub/command.h:25:0,
from ../../grub-core/loader/multiboot.c:30:
../../grub-core/loader/multiboot_elfxx.c: In function 'grub_multiboot_load_elf64':
../../grub-core/loader/multiboot_elfxx.c:130:28: error: 'relocatable' undeclared (first use in this function)
"load_base_addr=0x%x\n", relocatable,
This happens due to mistake in the commit 14ec665
(mbi: Use per segment a separate relocator chunk).
So, let's fix it.
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@no-log.org>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
When booting an arm* system on UEFI with an empty device tree (currently
only when hardware description comes from ACPI), we don't currently set
default to 1 cell (32 bits).
Set both of these properties, to 2 cells (64 bits), to resolve issues
with kexec on some platforms.
This change corresponds with linux kernel commit ae8a442dfdc4
("efi/libstub/arm*: Set default address and size cells values for an empty dtb")
and ensures booting through grub does not behave differently from booting
the stub loader directly.
See also https://patchwork.kernel.org/patch/9561201/
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Instead of setting up a all comprising relocator chunk for all segments,
use per segment a separate relocator chunk.
Currently, if the ELF is non-relocatable, a single relocator chunk will
comprise memory (between the segments) which gets overridden by the relst()
invocation of the movers code in grub_relocator16/32/64_boot().
The overridden memory may contain reserved ranges like VGA memory or ACPI
tables, which may lead to crashes or at least to strange boot behaviour.
Signed-off-by: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
These fields must reflect the ROM-BIOS's geometry for CHS-based
loaders to correctly load their next stage. Most loaders do not
query the ROM-BIOS (Int13.08), relying on the BPB fields to hold
the correct values already.
Tested with lDebug booted in qemu via grub2's
FreeDOS direct loading support, refer to
https://bitbucket.org/ecm/ldosboot + https://bitbucket.org/ecm/ldebug
(For this test, lDebug's iniload.asm must be assembled with
-D_QUERY_GEOMETRY=0 to leave the BPB values provided by grub.)
Signed-off-by: C. Masloch <pushbx@38.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Use kernel header struct and magic definition to align (and coexist) with
i386/arm64 ports.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Rename GRUB_LINUX_MAGIC_SIGNATURE GRUB_LINUX_I386_MAGIC_SIGNATURE,
to be usable in code that supports more than one image type.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The EFI page definitions and macros are generic and should not be confined
to arm64 headers - so move to efi/memory.h.
Also add EFI_PAGE_SIZE macro.
Update loader sources to reflect new header location.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The definition of bpb's num_total_sectors_16 and num_total_sectors_32
is that either the 16-bit field is non-zero and is used (in which case
eg mkfs.fat sets the 32-bit field to zero), or it is zero and the
32-bit field is used. Therefore, a BPB is invalid only if *both*
fields are zero; having one field as zero and the other as non-zero is
the case to be expected. (Indeed, according to Microsoft's specification
one of the fields *must* be zero, and the other non-zero.)
This affects all users of grub_chainloader_patch_bpb which are in
chainloader.c, freedos.c, and ntldr.c
Some descriptions of the semantics of these two fields:
https://www.win.tue.nl/~aeb/linux/fs/fat/fat-1.html
The old 2-byte fields "total number of sectors" and "number of
sectors per FAT" are now zero; this information is now found in
the new 4-byte fields.
(Here given in the FAT32 EBPB section but the total sectors 16/32 bit
fields semantic is true of FAT12 and FAT16 too.)
https://wiki.osdev.org/FAT#BPB_.28BIOS_Parameter_Block.29
19 | 2 | The total sectors in the logical volume. If this value is 0,
it means there are more than 65535 sectors in the volume, and the actual
count is stored in "Large Sectors (bytes 32-35).
32 | 4 | Large amount of sector on media. This field is set if there
are more than 65535 sectors in the volume.
(Doesn't specify what the "large" field is set to when unused, but as
mentioned mkfs.fat sets it to zero then.)
https://technet.microsoft.com/en-us/library/cc976796.aspx
0x13 | WORD | 0x0000 |
Small Sectors . The number of sectors on the volume represented in 16
bits (< 65,536). For volumes larger than 65,536 sectors, this field
has a value of zero and the Large Sectors field is used instead.
0x20 | DWORD | 0x01F03E00 |
Large Sectors . If the value of the Small Sectors field is zero, this
field contains the total number of sectors in the FAT16 volume. If the
value of the Small Sectors field is not zero, the value of this field
is zero.
https://staff.washington.edu/dittrich/misc/fatgen103.pdf page 10
BPB_TotSec16 | 19 | 2 |
This field is the old 16-bit total count of sectors on the volume.
This count includes the count of all sectors in all four regions of the
volume. This field can be 0; if it is 0, then BPB_TotSec32 must be
non-zero. For FAT32 volumes, this field must be 0. For FAT12 and
FAT16 volumes, this field contains the sector count, and
BPB_TotSec32 is 0 if the total sector count “fits” (is less than
0x10000).
BPB_TotSec32 | 32 | 4 |
This field is the new 32-bit total count of sectors on the volume.
This count includes the count of all sectors in all four regions of the
volume. This field can be 0; if it is 0, then BPB_TotSec16 must be
non-zero. For FAT32 volumes, this field must be non-zero. For
FAT12/FAT16 volumes, this field contains the sector count if
BPB_TotSec16 is 0 (count is greater than or equal to 0x10000).
(This specifies that an unused BPB_TotSec32 field is set to zero.)
By the way fix offsets in include/grub/fat.h.
Tested with lDebug booted in qemu via grub2's
FreeDOS direct loading support, refer to
https://bitbucket.org/ecm/ldosboot + https://bitbucket.org/ecm/ldebug
Signed-off-by: C. Masloch <pushbx@38.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The properties #address-cells and #size-cells are used to know the
number of cells for ranges provided by "regs". If they don't exist, the
value are resp. 2 and 1.
Currently, when multiboot nodes are created it is assumed that #address-cells
and #size-cells are exactly 2. However, they are never set by GRUB and
will result to later failure when the device-tree is generated by GRUB
or contain different values.
To prevent this failure, create the both properties in the chosen nodes.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
