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authorrwmjones <rjones@redhat.com>2016-10-07 13:56:27 +0100
committerLennart Poettering <lennart@poettering.net>2016-10-07 14:56:27 +0200
commit171b53380085b1288b03b19a2b978f36a5c003d0 (patch)
tree078261b58b89cfa5f2a190748a235065d7149ad3
parentfd9b26c6f208dda8e7235c7c793df2b5f162d015 (diff)
architecture: Add support for the RISC-V architecture. (#4305)
RISC-V is an open source ISA in development since 2010 at UCB. For more information, see https://riscv.org/ I am adding RISC-V support to Fedora: https://fedoraproject.org/wiki/Architectures/RISC-V There are three major variants of the architecture (32-, 64- and 128-bit). The 128-bit variant is a paper exercise, but the other two really exist in silicon. RISC-V is always little endian. On Linux, the default kernel uname(2) can return "riscv" for all variants. However a patch was added recently which makes the kernel return one of "riscv32" or "riscv64" (or in future "riscv128"). So systemd should be prepared to handle any of "riscv", "riscv32" or "riscv64" (in future, "riscv128" but that is not included in the current patch). If the kernel returns "riscv" then you need to use the pointer size in order to know the real variant. The Fedora/RISC-V kernel only ever returns "riscv64" since we're only doing Fedora for 64 bit at the moment, and we've patched the kernel so it doesn't return "riscv". As well as the major bitsize variants, there are also architecture extensions. However I'm trying to ensure that uname(2) does *not* return any other information about those in utsname.machine, so that we don't end up with "riscv64abcde" nonsense. Instead those extensions will be exposed in /proc/cpuinfo similar to how flags work in x86.
-rw-r--r--src/basic/architecture.c10
-rw-r--r--src/basic/architecture.h12
2 files changed, 22 insertions, 0 deletions
diff --git a/src/basic/architecture.c b/src/basic/architecture.c
index b1c8e91f50..b74dc0db78 100644
--- a/src/basic/architecture.c
+++ b/src/basic/architecture.c
@@ -123,6 +123,14 @@ int uname_architecture(void) {
{ "crisv32", ARCHITECTURE_CRIS },
#elif defined(__nios2__)
{ "nios2", ARCHITECTURE_NIOS2 },
+#elif defined(__riscv__)
+ { "riscv32", ARCHITECTURE_RISCV32 },
+ { "riscv64", ARCHITECTURE_RISCV64 },
+# if __SIZEOF_POINTER__ == 4
+ { "riscv", ARCHITECTURE_RISCV32 },
+# elif __SIZEOF_POINTER__ == 8
+ { "riscv", ARCHITECTURE_RISCV64 },
+# endif
#else
#error "Please register your architecture here!"
#endif
@@ -174,6 +182,8 @@ static const char *const architecture_table[_ARCHITECTURE_MAX] = {
[ARCHITECTURE_TILEGX] = "tilegx",
[ARCHITECTURE_CRIS] = "cris",
[ARCHITECTURE_NIOS2] = "nios2",
+ [ARCHITECTURE_RISCV32] = "riscv32",
+ [ARCHITECTURE_RISCV64] = "riscv64",
};
DEFINE_STRING_TABLE_LOOKUP(architecture, int);
diff --git a/src/basic/architecture.h b/src/basic/architecture.h
index b3e4d85906..5a77c31932 100644
--- a/src/basic/architecture.h
+++ b/src/basic/architecture.h
@@ -58,6 +58,8 @@ enum {
ARCHITECTURE_TILEGX,
ARCHITECTURE_CRIS,
ARCHITECTURE_NIOS2,
+ ARCHITECTURE_RISCV32,
+ ARCHITECTURE_RISCV64,
_ARCHITECTURE_MAX,
_ARCHITECTURE_INVALID = -1
};
@@ -191,6 +193,16 @@ int uname_architecture(void);
#elif defined(__nios2__)
# define native_architecture() ARCHITECTURE_NIOS2
# define LIB_ARCH_TUPLE "nios2-linux-gnu"
+#elif defined(__riscv__)
+# if __SIZEOF_POINTER__ == 4
+# define native_architecture() ARCHITECTURE_RISCV32
+# define LIB_ARCH_TUPLE "riscv32-linux-gnu"
+# elif __SIZEOF_POINTER__ == 8
+# define native_architecture() ARCHITECTURE_RISCV64
+# define LIB_ARCH_TUPLE "riscv64-linux-gnu"
+# else
+# error "Unrecognized riscv architecture variant"
+# endif
#else
# error "Please register your architecture here!"
#endif