summaryrefslogtreecommitdiffstats
path: root/arch/arm/Kconfig
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/Kconfig')
-rw-r--r--arch/arm/Kconfig32
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5ebc5d922ea1..73c320ea172c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1781,6 +1781,38 @@ config ZBOOT_ROM_SH_MOBILE_SDHI
endchoice
+config ARM_APPENDED_DTB
+ bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
+ depends on OF && !ZBOOT_ROM && EXPERIMENTAL
+ help
+ With this option, the boot code will look for a device tree binary
+ (DTB) appended to zImage
+ (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
+
+ This is meant as a backward compatibility convenience for those
+ systems with a bootloader that can't be upgraded to accommodate
+ the documented boot protocol using a device tree.
+
+ Beware that there is very little in terms of protection against
+ this option being confused by leftover garbage in memory that might
+ look like a DTB header after a reboot if no actual DTB is appended
+ to zImage. Do not leave this option active in a production kernel
+ if you don't intend to always append a DTB. Proper passing of the
+ location into r2 of a bootloader provided DTB is always preferable
+ to this option.
+
+config ARM_ATAG_DTB_COMPAT
+ bool "Supplement the appended DTB with traditional ATAG information"
+ depends on ARM_APPENDED_DTB
+ help
+ Some old bootloaders can't be updated to a DTB capable one, yet
+ they provide ATAGs with memory configuration, the ramdisk address,
+ the kernel cmdline string, etc. Such information is dynamically
+ provided by the bootloader and can't always be stored in a static
+ DTB. To allow a device tree enabled kernel to be used with such
+ bootloaders, this option allows zImage to extract the information
+ from the ATAG list and store it at run time into the appended DTB.
+
config CMDLINE
string "Default kernel command string"
default ""
OpenPOWER on IntegriCloud