[coreboot-gerrit] Change in ...coreboot[master]: arch/x86: drop special case cbfs locator

Patrick Georgi (Code Review) gerrit at coreboot.org
Thu Nov 22 17:31:16 CET 2018


Patrick Georgi has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/29801


Change subject: arch/x86: drop special case cbfs locator
......................................................................

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 at google.com>
Reported-by: Werner Zeh <werner.zeh at siemens.com>
---
M src/arch/x86/mmap_boot.c
1 file changed, 0 insertions(+), 41 deletions(-)



  git pull ssh://review.coreboot.org:29418/coreboot refs/changes/01/29801/1

diff --git a/src/arch/x86/mmap_boot.c b/src/arch/x86/mmap_boot.c
index 168b17d..2432201 100644
--- a/src/arch/x86/mmap_boot.c
+++ b/src/arch/x86/mmap_boot.c
@@ -28,44 +28,3 @@
 {
 	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,
-};

-- 
To view, visit https://review.coreboot.org/c/coreboot/+/29801
To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings

Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-Change-Id: I6fa78073ee4015d7769ed588dc67f9b019d42d07
Gerrit-Change-Number: 29801
Gerrit-PatchSet: 1
Gerrit-Owner: Patrick Georgi <pgeorgi at google.com>
Gerrit-MessageType: newchange
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.coreboot.org/pipermail/coreboot-gerrit/attachments/20181122/ef2a0c9f/attachment.html>


More information about the coreboot-gerrit mailing list