u-boot: remove UBOOT_MACHINE and COMPATIBLE_MACHINES

oe-core does not define any machines, so it does not make sense to
add machine specific information in the oe-core u-boot recipe and
infrastructure. Also note that COMPATIBLE_MACHINES is not easily extended due to
its regex syntax: "(machine_a|machine_b)", making it difficult to extend the
u-boot recipe in bbappend files without resorting to machine specific overrides.

Remove COMPATIBLE_MACHINES and the default UBOOT_MACHINE from the recipe and
insert some anonymous python into u-boot.inc to raise SkipPackage if
UBOOT_MACHINE is not set (this ensures 'world' still works for machines that
can't build u-boot).

UBOOT_MACHINE must now be specified in each machine config that requires u-boot.
This is an improvement over requiring machine specific overrides in every BSP
layer's u-boot_git.bbappend file. For example, a beagleboard machine config
currently contains:

UBOOT_ENTRYPOINT = "0x80008000"
UBOOT_LOADADDRESS = "0x80008000"

With this change, it must now contain:

UBOOT_MACHINE = "omap3_beagle_config"
UBOOT_ENTRYPOINT = "0x80008000"
UBOOT_LOADADDRESS = "0x80008000"

So long as the SRC_URI in the base recipe can build a working u-boot for a given
machine, there is no need to create a u-boot_git.bbappend file. If additional
patches are deemed necessary, a BSP layer creates a u-boot_git.bbappend file and
extends the SRC_URI to include general or machine specific backports.

Note: I used bb.note() instead of bb.debug() to ensure the message at least
      makes it to the console. From what I could gather, bb.debug() doesn't
      go anywhere during recipe parsing.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Koen Kooi <koen@dominion.thruhere.net>
Cc: Jason Kridner <jkridner@beagleboard.org>
Cc: Chris Larson <clarson@kergoth.com>

2 files changed, 15 insertions, 6 deletions

diff --git a/meta/recipes-bsp/uboot/u-boot.inc b/meta/recipes-bsp/uboot/u-boot.inc
index 058e3bad1..83dfb6fa8 100644
--- a/meta/recipes-bsp/uboot/u-boot.inc
+++ b/meta/recipes-bsp/uboot/u-boot.inc
@@ -11,7 +11,15 @@ PARALLEL_MAKE=""
 # GCC 4.5.1 builds unusable binaries using -Os, remove it from OPTFLAGS
 EXTRA_OEMAKE = "CROSS_COMPILE=${TARGET_PREFIX} OPTFLAGS='-O2'"
 
-UBOOT_MACHINE ?= "${MACHINE}_config"
+python () {
+	if not d.getVar("UBOOT_MACHINE", True):
+		PN = d.getVar("PN", True)
+		FILE = os.path.basename(d.getVar("FILE", True))
+		bb.debug(1, "To build %s, see %s for instructions on \
+			     setting up your machine config" % (PN, FILE))
+		raise bb.parse.SkipPackage("because UBOOT_MACHINE is not set")
+}
+
 UBOOT_IMAGE ?= "u-boot-${MACHINE}-${PV}-${PR}.bin"
 UBOOT_SYMLINK ?= "u-boot-${MACHINE}.bin"
 UBOOT_MAKE_TARGET ?= "all"
diff --git a/meta/recipes-bsp/uboot/u-boot_git.bb b/meta/recipes-bsp/uboot/u-boot_git.bb
index 4c8f5df59..0fbb9ba18 100644
--- a/meta/recipes-bsp/uboot/u-boot_git.bb
+++ b/meta/recipes-bsp/uboot/u-boot_git.bb
@@ -1,5 +1,11 @@
 require u-boot.inc
 
+# To build u-boot for your machine, provide the following lines in your machine
+# config, replacing the assignments as appropriate for your machine.
+# UBOOT_MACHINE = "omap3_beagle_config"
+# UBOOT_ENTRYPOINT = "0x80008000"
+# UBOOT_LOADADDRESS = "0x80008000"
+
 LICENSE = "GPLv2+"
 LIC_FILES_CHKSUM = "file://COPYING;md5=1707d6db1d42237583f50183a5651ecb \
                     file://README;beginline=1;endline=22;md5=3a00ef51d3fc96e9d6c1bc4708ccd3b5"
@@ -12,11 +18,6 @@ PR="r3"
 
 SRC_URI = "git://git.denx.de/u-boot.git;branch=master;protocol=git"
 
-UBOOT_MACHINE_beagleboard = "omap3_beagle_config"
-UBOOT_MACHINE_overo = "omap3_overo_config"
-
 S = "${WORKDIR}/git"
 
 PACKAGE_ARCH = "${MACHINE_ARCH}"
-
-COMPATIBLE_MACHINE = "(beagleboard|overo)"