riscv: Add a helper routine to print CPU information
This adds a helper routine to print CPU information. Currently
it prints all the instruction set extensions that the processor
core supports.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c
new file mode 100644
index 0000000..ae57fb8
--- /dev/null
+++ b/arch/riscv/cpu/cpu.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <asm/csr.h>
+
+enum {
+ ISA_INVALID = 0,
+ ISA_32BIT,
+ ISA_64BIT,
+ ISA_128BIT
+};
+
+static const char * const isa_bits[] = {
+ [ISA_INVALID] = NULL,
+ [ISA_32BIT] = "32",
+ [ISA_64BIT] = "64",
+ [ISA_128BIT] = "128"
+};
+
+static inline bool supports_extension(char ext)
+{
+ return csr_read(misa) & (1 << (ext - 'a'));
+}
+
+int print_cpuinfo(void)
+{
+ char name[32];
+ char *s = name;
+ int bit;
+
+ s += sprintf(name, "rv");
+ bit = csr_read(misa) >> (sizeof(long) * 8 - 2);
+ s += sprintf(s, isa_bits[bit]);
+
+ supports_extension('i') ? *s++ = 'i' : 'r';
+ supports_extension('m') ? *s++ = 'm' : 'i';
+ supports_extension('a') ? *s++ = 'a' : 's';
+ supports_extension('f') ? *s++ = 'f' : 'c';
+ supports_extension('d') ? *s++ = 'd' : '-';
+ supports_extension('c') ? *s++ = 'c' : 'v';
+ *s++ = '\0';
+
+ printf("CPU: %s\n", name);
+
+ return 0;
+}