Add initial build infrastructure

conf/initramfs.txt

@@ -0,0 +1,4 @@
+dir /dev 755 0 0
+nod /dev/console 644 0 0 c 5 1
+nod /dev/null 644 0 0 c 1 3
+slink /init /bin/busybox 755 0 0

conf/linux_defconfig

@@ -0,0 +1,54 @@
+# CONFIG_COMPACTION is not set
+CONFIG_HZ_100=y
+CONFIG_CROSS_COMPILE="riscv64-unknown-linux-gnu-"
+CONFIG_DEFAULT_HOSTNAME="ucbvax"
+# CONFIG_CROSS_MEMORY_ATTACH is not set
+CONFIG_NAMESPACES=y
+CONFIG_BLK_DEV_INITRD=y
+# CONFIG_RD_BZIP2 is not set
+# CONFIG_RD_LZMA is not set
+# CONFIG_RD_XZ is not set
+# CONFIG_RD_LZO is not set
+# CONFIG_RD_LZ4 is not set
+CONFIG_EMBEDDED=y
+# CONFIG_BLK_DEV_BSG is not set
+CONFIG_PARTITION_ADVANCED=y
+# CONFIG_EFI_PARTITION is not set
+# CONFIG_IOSCHED_DEADLINE is not set
+CONFIG_NET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
+# CONFIG_INET_XFRM_MODE_TUNNEL is not set
+# CONFIG_INET_XFRM_MODE_BEET is not set
+# CONFIG_INET_LRO is not set
+# CONFIG_INET_DIAG is not set
+# CONFIG_IPV6 is not set
+# CONFIG_WIRELESS is not set
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+# CONFIG_FIRMWARE_IN_KERNEL is not set
+# CONFIG_BLK_DEV is not set
+# CONFIG_INPUT_MOUSEDEV is not set
+# CONFIG_INPUT_KEYBOARD is not set
+# CONFIG_INPUT_MOUSE is not set
+# CONFIG_VT is not set
+# CONFIG_HW_RANDOM is not set
+# CONFIG_HWMON is not set
+# CONFIG_USB_SUPPORT is not set
+# CONFIG_IOMMU_SUPPORT is not set
+CONFIG_EXT2_FS=y
+# CONFIG_FILE_LOCKING is not set
+# CONFIG_DNOTIFY is not set
+# CONFIG_INOTIFY_USER is not set
+# CONFIG_PROC_PAGE_MONITOR is not set
+CONFIG_TMPFS=y
+# CONFIG_MISC_FILESYSTEMS is not set
+# CONFIG_NETWORK_FILESYSTEMS is not set
+CONFIG_EARLY_PRINTK=y
+CONFIG_PRINTK_TIME=y
+CONFIG_STRIP_ASM_SYMS=y
+CONFIG_DEBUG_SECTION_MISMATCH=y
+# CONFIG_FRAME_POINTER is not set
+# CONFIG_CRYPTO_ANSI_CPRNG is not set
+# CONFIG_CRYPTO_HW is not set