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Don't run any Option ROMs stored outside of the system flash 

Right now coreboot only executes VGA Option ROMs. However, this is not
good enough. For security reasons we want to execute only Option ROMs
stored in our r/o CBFS.

This patch adds a new option to disable execution of arbitrary Option
ROMs.

Also fix the capitalization of Option ROM in src/devices/Kconfig

Change-Id: I485291c06ec5cd1f875357401831fe32ccfc5f2f
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/730
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-by: Mathias Krause <minipli@googlemail.com>
This commit is contained in:
Stefan Reinauer 2011-10-06 16:47:51 -07:00 committed by Mathias Krause
parent 1025f3afc8
commit afaa25776f
2 changed files with 35 additions and 16 deletions
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43
src/devices/Kconfig
View File

@ -27,28 +27,41 @@ config VGA_BRIDGE_SETUP
# TODO: Explain differences (if any) for onboard cards.
config VGA_ROM_RUN
bool "Run VGA option ROMs"
bool "Run VGA Option ROMs"
default y
help
Execute VGA option ROMs, if found. This is required to enable
Execute VGA Option ROMs, if found. This is required to enable
PCI/AGP/PCI-E video cards.
config S3_VGA_ROM_RUN
bool "Re-run VGA option ROMs on S3 resume"
bool "Re-run VGA Option ROMs on S3 resume"
default y
depends on VGA_ROM_RUN && HAVE_ACPI_RESUME
help
Execute VGA option ROMs when coming out of an S3 resume.
Execute VGA Option ROMs when coming out of an S3 resume.
config PCI_ROM_RUN
bool "Run non-VGA option ROMs"
bool "Run non-VGA Option ROMs"
default y
help
Execute non-VGA PCI option ROMs, if found.
Execute non-VGA PCI Option ROMs, if found.
Examples include IDE/SATA controller option ROMs and option ROMs
Examples include IDE/SATA controller Option ROMs and Option ROMs
for network cards (NICs).
config ON_DEVICE_ROM_RUN
bool "Run Option ROMs on PCI devices"
default y
help
Execute Option ROMs that are stored on PCI/PCIe/AGP devices.
If disabled, only Option ROMs stored in CBFS will be executed. If
you are concerned about security, you might want to disable this
option, but it might leave your system in a state of degraded
functionality.
If unsure, say Y
choice
prompt "Option ROM execution type"
default PCI_OPTION_ROM_RUN_YABEL if !ARCH_X86
@ -60,7 +73,7 @@ config PCI_OPTION_ROM_RUN_REALMODE
bool
depends on ARCH_X86
help
If you select this option, PCI option ROMs will be executed
If you select this option, PCI Option ROMs will be executed
natively on the CPU in real mode. No CPU emulation is involved,
so this is the fastest, but also the least secure option.
(only works on x86/x64 systems)
@ -71,11 +84,11 @@ config PCI_OPTION_ROM_RUN_YABEL
depends on !GEODE_VSA
help
If you select this option, the x86emu CPU emulator will be used to
execute PCI option ROMs.
execute PCI Option ROMs.
This option prevents option ROMs from doing dirty tricks with the
This option prevents Option ROMs from doing dirty tricks with the
system (such as installing SMM modules or hypervisors), but it is
also significantly slower than the native option ROM initialization
also significantly slower than the native Option ROM initialization
method.
This is the default choice for non-x86 systems.
@ -83,13 +96,13 @@ config PCI_OPTION_ROM_RUN_YABEL
endchoice
config YABEL_PCI_ACCESS_OTHER_DEVICES
prompt "Allow option ROMs to access other devices"
prompt "Allow Option ROMs to access other devices"
bool
depends on PCI_OPTION_ROM_RUN_YABEL
help
Per default, YABEL only allows option ROMs to access the PCI device
Per default, YABEL only allows Option ROMs to access the PCI device
that they are associated with. However, this causes trouble for some
onboard graphics chips whose option ROM needs to reconfigure the
onboard graphics chips whose Option ROM needs to reconfigure the
north bridge.
config YABEL_VIRTMEM_LOCATION
@ -118,7 +131,7 @@ config YABEL_DIRECTHW
When choosing this option, x86emu will pass through all hardware
accesses to memory and I/O devices to the underlying memory and I/O
addresses. While this option prevents option ROMs from doing dirty
addresses. While this option prevents Option ROMs from doing dirty
tricks with the CPU (such as installing SMM modules or hypervisors),
they can still access all devices in the system.
Enable this option for a good compromise between security and speed.

8
src/devices/pci_rom.c
View File

@ -71,9 +71,15 @@ struct rom_header *pci_rom_probe(struct device *dev)
rom_address|PCI_ROM_ADDRESS_ENABLE);
}
printk(BIOS_DEBUG, "On card, ROM address for %s = %lx\n",
#if CONFIG_ON_DEVICE_ROM_RUN
printk(BIOS_DEBUG, "Option ROM address for %s = %lx\n",
dev_path(dev), (unsigned long)rom_address);
rom_header = (struct rom_header *)rom_address;
#else
printk(BIOS_DEBUG, "Option ROM execution disabled "
"for %s\n", dev_path(dev));
return NULL;
#endif
}
printk(BIOS_SPEW, "PCI expansion ROM, signature 0x%04x, "