ref: cfda4c39d69c6653c16520276b7209cfcdf031cb
parent: d744632a356e28dd453c084dc9a2172559103b31
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Tue Dec 22 19:04:43 EST 2020
add preliminary riscv64 support from archlinux (thanks Sören Tempel)
--- /dev/null
+++ b/posix-riscv64/Makefile
@@ -1,0 +1,18 @@
+ROOT=..
+include ../Make.config
+LIB=../libmachdep.a
+
+OFILES=\
+ getcallerpc.$O\
+ tas.$O
+
+default: $(LIB)
+$(LIB): $(OFILES)
+ $(AR) r $(LIB) $(OFILES)
+ $(RANLIB) $(LIB)
+
+%.$O: %.c
+ $(CC) $(CFLAGS) $*.c
+
+%.$O: %.s
+ $(AS) -o $*.$O $*.s
--- /dev/null
+++ b/posix-riscv64/getcallerpc.c
@@ -1,0 +1,8 @@
+#include "u.h"
+#include "libc.h"
+
+uintptr
+getcallerpc(void *a)
+{+ return ((uintptr*)a)[-1];
+}
--- /dev/null
+++ b/posix-riscv64/tas.c
@@ -1,0 +1,28 @@
+#include "u.h"
+#include "libc.h"
+
+int
+tas(int *x)
+{+ int v, i = 1;
+
+ __asm__(
+ "1: lr.w t0, (%1)\n"
+ " sc.w t1, %2, (%1)\n"
+ " bnez t1, 1b\n"
+ " mv %0, t0"
+ : "=r" (v)
+ : "r" (x), "r" (i)
+ : "t1", "t0"
+ );
+
+ switch(v) {+ case 0:
+ case 1:
+ return v;
+ default:
+ print("canlock: corrupted 0x%lux\n", v);+ return 1;
+ }
+}
+