Initial drop

Add some riscv code

Signed-off-by: Carlos Maiolino <[email protected]>

2 files changed, 72 insertions, 0 deletions

diff --git a/riscv/riscv-probe/examples/probe/probe.c b/riscv/riscv-probe/examples/probe/probe.c
new file mode 100644
index 0000000..4cc4384
--- /dev/null
+++ b/riscv/riscv-probe/examples/probe/probe.c
@@ -0,0 +1,71 @@
+#include "femto.h"
+
+#ifdef __riscv
+#include "arch/riscv/csr.h"
+#include "arch/riscv/trap.h"
+#include "arch/riscv/encoding.h"
+#include "arch/riscv/machine.h"
+
+#define MCAUSE_UNSET 0xabbaabba
+
+static volatile uintptr_t save_mcause;
+
+static void trap_save_cause(uintptr_t* regs, uintptr_t mcause, uintptr_t mepc)
+{
+	save_mcause = mcause;
+	write_csr(mepc, mepc + 4);
+}
+
+static const char* isa_string(char *buf, size_t bufsz)
+{
+	static const char *ext = "iemafdqlcbjtpvnsu";
+
+	const char *p = ext;
+	char *q = buf + snprintf(buf, bufsz, "rv%d", xlen());
+	do {
+		if (has_ext(*p)) {
+			*q++ = *p;
+		}
+	} while (*++p);
+	*q = '\0';
+
+	return buf;
+}
+
+static void probe_all_csrs()
+{
+	int *csrenum = csr_enum_array();
+	const char **csrnames = csr_name_array();
+	const char* ws = "               ";
+	set_trap_fn(trap_save_cause);
+	while (*csrenum != csr_none) {
+		save_mcause = MCAUSE_UNSET;
+		long value = read_csr_enum(*csrenum);
+		const char* csrname = csrnames[*csrenum];
+		if (save_mcause != MCAUSE_UNSET) {
+			int async = save_mcause < 0;
+			int cause = save_mcause & (((uintptr_t)-1) >> async);
+			printf("csr: %s%s %s cause=%ld mtval=0x%lx\n",
+				csrname, ws + strlen(csrname), cause < 16
+				? (async ? riscv_intr_names : riscv_excp_names)[cause]
+				: "(unknown)", save_mcause, read_csr_enum(csr_mtval));
+		} else {
+			printf("csr: %s%s 0x%lx\n",
+				csrname, ws + strlen(csrname), value);
+		}
+		csrenum++;
+	}
+}
+#endif
+
+int main(int argc, char **argv)
+{
+#ifdef __riscv
+	char buf[32];
+	printf("isa: %s\n", isa_string(buf, sizeof(buf)));
+	probe_all_csrs();
+	printf("\n");
+#else
+	puts("architecture-not-supported");
+#endif
+}
diff --git a/riscv/riscv-probe/examples/probe/rules.mk b/riscv/riscv-probe/examples/probe/rules.mk
new file mode 100644
index 0000000..928f066
--- /dev/null
+++ b/riscv/riscv-probe/examples/probe/rules.mk
@@ -0,0 +1 @@
+probe_objs = probe.o