[U-Boot] [PATCH v2 1/1] x86: provide CONFIG_BUILD_ROM

[Heinrich Schuchardt]

Up to now we depended on an exported variable to build u-boot.rom.
What we build should be specified by the configuration file.

With this patch the export variable is deprecated and replaced by the
Kconfig option CONFIG_BUILD_ROM. To make the change as smooth as
possible 'export BUILD_ROM' is still usable but removed from the
documentation.

This option depends on CONFIG_X86 and is selected in
qemu-x86_defconfig and qemu-x86_64_defconfig.

Cc: Bin Meng <bmeng.cn at gmail.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
v2
	Enable CONFIG_BUILD_ROM for qemu-x86_64_defconfig
	as suggested by Bin.
	Fix typos.
	Remove 'default n'
---
 Kconfig                       | 10 ++++++++++
 Makefile                      |  2 +-
 configs/qemu-x86_64_defconfig |  1 +
 configs/qemu-x86_defconfig    |  1 +
 doc/README.x86                |  2 +-
 5 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/Kconfig b/Kconfig
index 238fa3e1ed..989d81c04c 100644
--- a/Kconfig
+++ b/Kconfig
@@ -158,6 +158,15 @@ config PHYS_64BIT
 	  This can be used not only for 64bit SoCs, but also for
 	  large physical address extention on 32bit SoCs.
 
+config BUILD_ROM
+	bool "Build U-Boot as BIOS replacement"
+	depends on X86
+	help
+	  This option allows to build a ROM version of U-Boot.
+	  The build process generally requires several binary blobs
+	  which are not shipped in the U-Boot source tree.
+	  Please, see doc/README.x86 for details.
+
 endmenu		# General setup
 
 menu "Boot images"
diff --git a/Makefile b/Makefile
index 8250b3409a..50fe0003f5 100644
--- a/Makefile
+++ b/Makefile
@@ -796,7 +796,7 @@ ALL-$(CONFIG_REMAKE_ELF) += u-boot.elf
 ALL-$(CONFIG_EFI_APP) += u-boot-app.efi
 ALL-$(CONFIG_EFI_STUB) += u-boot-payload.efi
 
-ifneq ($(BUILD_ROM),)
+ifneq ($(BUILD_ROM)$(CONFIG_BUILD_ROM),)
 ALL-$(CONFIG_X86_RESET_VECTOR) += u-boot.rom
 endif
 
diff --git a/configs/qemu-x86_64_defconfig b/configs/qemu-x86_64_defconfig
index 67e9a45fbc..a6a14a8de9 100644
--- a/configs/qemu-x86_64_defconfig
+++ b/configs/qemu-x86_64_defconfig
@@ -1,4 +1,5 @@
 CONFIG_X86=y
+CONFIG_BUILD_ROM=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y
 CONFIG_SPL_LIBGENERIC_SUPPORT=y
 CONFIG_SYS_MALLOC_F_LEN=0x1000
diff --git a/configs/qemu-x86_defconfig b/configs/qemu-x86_defconfig
index 7ce97ff091..346abf621d 100644
--- a/configs/qemu-x86_defconfig
+++ b/configs/qemu-x86_defconfig
@@ -1,4 +1,5 @@
 CONFIG_X86=y
+CONFIG_BUILD_ROM=y
 CONFIG_MAX_CPUS=2
 CONFIG_DEFAULT_DEVICE_TREE="qemu-x86_i440fx"
 CONFIG_SMP=y
diff --git a/doc/README.x86 b/doc/README.x86
index c96a22cb08..226c9af281 100644
--- a/doc/README.x86
+++ b/doc/README.x86
@@ -82,7 +82,7 @@ shipped in the U-Boot source tree. Due to this reason, the u-boot.rom build is
 not turned on by default in the U-Boot source tree. Firstly, you need turn it
 on by enabling the ROM build:
 
-$ export BUILD_ROM=y
+CONFIG_BUILD_ROM=y
 
 This tells the Makefile to build u-boot.rom as a target.
 
-- 
2.11.0