Add a simple README file to describe each subdir
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+# Virtual Boot ROM for NPCM SoCs
+
+This repository contains simple Boot ROMs for Nuvoton based
+BMC images that are intended to be used by [QEMU](http://www.qemu.org)
+when emulating NPCM based machines.
+
+## Subdirectories
+
+npcm7xx: This subdir contains Boot ROM for NPCM7XX, a 32-bit ARM image.
+npcm8xx: This subdir contains Boot ROM for NPCM8XX, a 64-bit ARM image.