Merge pull request #1020 from sifive/dev/paulw/rv64-fixed

riscv: add rv64gc support

config/arch/riscv.in

@@ -4,9 +4,12 @@
 ## depends on EXPERIMENTAL
 ##
 ## select ARCH_SUPPORTS_32
+## select ARCH_SUPPORTS_64
 ## select ARCH_DEFAULT_32
+## select ARCH_SUPPORTS_BOTH_MMU
 ## select ARCH_SUPPORTS_WITH_ABI
 ## select ARCH_SUPPORTS_WITH_ARCH
+## select ARCH_SUPPORTS_WITH_TUNE
 ## select GCC_REQUIRE_7_or_later
 
 ## help The RISC-V architecture, as defined by:

samples/riscv64-unknown-linux-gnu/crosstool.config

@@ -0,0 +1,12 @@
+CT_EXPERIMENTAL=y
+CT_ARCH_RISCV=y
+# CT_DEMULTILIB is not set
+CT_ARCH_USE_MMU=y
+CT_ARCH_64=y
+CT_KERNEL_LINUX=y
+CT_DEBUG_GDB=y
+# CT_GDB_CROSS_PYTHON is not set
+# CT_GDB_GDBSERVER is not set
+CT_ZLIB_NEEDED=y
+CT_TARGET_VENDOR="unknown"
+CT_ARCH_ARCH="rv64gc"

samples/riscv64-unknown-linux-gnu/reported.by

@@ -0,0 +1,3 @@
+reporter_name="Paul Walmsley <paul.walmsley@sifive.com>"
+reporter_url="https://www.sifive.com/"
+reporter_comment=""