path: root/doc
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authorSimon Glass <>2015-01-27 22:13:32 -0700
committerSimon Glass <>2015-02-05 22:16:43 -0700
commiteea0f11278d9104960dfb1fbfcddfb796a3e0bb5 (patch)
treea7bc1309e894bc9e56eaec6f0aedc3bfa34f562a /doc
parent316328f59d5bb64ed8ab70b68edb434cae70ee58 (diff)
x86: Add an option to enabling building a ROM file
Rather than requiring the Makefile to be modified, provide a build option to enable the ROM to be built. We cannot do this by default since it requires binary blobs. Without these the build will fail. Signed-off-by: Simon Glass <> Reviewed-by: Bin Meng <>
Diffstat (limited to 'doc')
1 files changed, 6 insertions, 4 deletions
diff --git a/doc/README.x86 b/doc/README.x86
index 7df8cc516a..ddfd75e1cd 100644
--- a/doc/README.x86
+++ b/doc/README.x86
@@ -51,9 +51,11 @@ Building ROM version of U-Boot (hereafter referred to as u-boot.rom) is a
little bit tricky, as generally it requires several binary blobs which are not
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 uncommenting the following line in the main U-Boot Makefile:
+on by enabling the ROM build:
-# ALL-$(CONFIG_X86_RESET_VECTOR) += u-boot.rom
+$ export BUILD_ROM=y
+This tells the Makefile to build u-boot.rom as a target.
Link-specific instructions:
@@ -126,11 +128,11 @@ Make sure 0x1110000 matches CONFIG_SYS_TEXT_BASE and 0x1110015 matches the
symbol address of _start (in arch/x86/cpu/start.S).
If you want to use ELF as the coreboot payload, change U-Boot configuration to
CPU Microcode
-Modern CPU usually requires a special bit stream called microcode [5] to be
+Modern CPUs usually require a special bit stream called microcode [5] to be
loaded on the processor after power up in order to function properly. U-Boot
has already integrated these as hex dumps in the source tree.
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