nds32: Enable FPU if the version of CPU supported
Some version of Andes core support FPU coprocessor,
if this is the case, and toolchain support FPU instruction set,
we should enable it at low level initialization time.
Signed-off-by: Kuan-Yu Kuo <ken.kuoky@gmail.com>
Cc: Macpaul Lin <macpaul@gmail.com>
diff --git a/arch/nds32/cpu/n1213/ag102/lowlevel_init.S b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
index d842afa..d3b9e16 100644
--- a/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
+++ b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
@@ -114,6 +114,11 @@
led 0x20
jal remap
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+ led 0x2f
+ jal enable_fpu
+#endif
+
led 0x30
ret $r10
@@ -288,6 +293,27 @@
move $lp, $r11
2:
ret
+
+ /*
+ * enable_fpu:
+ * Some of Andes CPU version support FPU coprocessor, if so,
+ * and toolchain support FPU instruction set, we should enable it.
+ */
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+enable_fpu:
+ mfsr $r0, $CPU_VER /* enable FPU if it exists */
+ srli $r0, $r0, 3
+ andi $r0, $r0, 1
+ beqz $r0, 1f /* skip if no COP */
+ mfsr $r0, $FUCOP_EXIST
+ srli $r0, $r0, 31
+ beqz $r0, 1f /* skip if no FPU */
+ mfsr $r0, $FUCOP_CTL
+ ori $r0, $r0, 1
+ mtsr $r0, $FUCOP_CTL
+1:
+ ret
+#endif
.globl show_led
show_led: