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arch/x86: drop special case cbfs locator 

CBFS used to have a special region for the x86 bootblock, which also
contained a pointer to a CBFS master header, which describes the
layout of the CBFS.

Since we adopted other architectures, we got rid of the bootblock region
as a separate entity and add the x86 bootblock as a CBFS file now.

The master header still exists for compatibility with old cbfstool
versions, but it's neatly wrapped in either the bootblock file or in a
file carefully crafted at the right location (on all other architectures).

All the layout information we need is now available from FMAP, a core
part of a contemporary coreboot image, even on x86, so we can just use
the generic master header locator in src/lib/cbfs.c and get rid of the
special version.

Among the advantages: the x86 header locator reduced the size of the
CBFS by 64 bytes assuming that there's the bootblock region of at least
that size - this breaks assumptions elsewhere (eg. when walking CBFS in
cbfs_boot_locate() because the last file, the bootblock, will exceed the
CBFS region as seen by coreboot (since it's CBFS - 64bytes).

TEST=emulation/qemu-q35 still boots

Change-Id: I6fa78073ee4015d7769ed588dc67f9b019d42d07
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reported-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/c/29801
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
This commit is contained in:
Patrick Georgi 2018-11-22 17:19:31 +01:00
parent b3070a5f1b
commit caf6d0bc52
1 changed files with 0 additions and 41 deletions
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41
src/arch/x86/mmap_boot.c
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@ -28,44 +28,3 @@ const struct region_device *boot_device_ro(void)
{ {
return &boot_dev.rdev; return &boot_dev.rdev;
} }
static int cbfs_master_header_props(struct cbfs_props *props)
{
struct cbfs_header header;
int32_t offset;
const struct region_device *bdev;
bdev = boot_device_ro();
rdev_readat(bdev, &offset, CONFIG_ROM_SIZE - sizeof(offset),
sizeof(offset));
/* The offset is relative to the end of the media. */
offset += CONFIG_ROM_SIZE;
rdev_readat(bdev, &header, offset, sizeof(header));
header.magic = ntohl(header.magic);
header.romsize = ntohl(header.romsize);
header.bootblocksize = ntohl(header.bootblocksize);
header.offset = ntohl(header.offset);
if (header.magic != CBFS_HEADER_MAGIC)
return -1;
props->offset = header.offset;
if (header.romsize != CONFIG_ROM_SIZE)
props->size = CONFIG_ROM_SIZE;
else
props->size = header.romsize;
props->size -= props->offset;
props->size -= header.bootblocksize;
props->size = ALIGN_DOWN(props->size, 64);
return 0;
}
const struct cbfs_locator cbfs_master_header_locator = {
.name = "Master Header Locator",
.locate = cbfs_master_header_props,
};