Changeset 36e5eb3 in mainline for kernel/arch/arm32/src/fpu_context.c

Timestamp:

2012-11-24T20:09:36Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

65871bb

Parents:

435c33b

Message:

arm32: Fix fpu detection on older arms.

mvfr0 is not available unless vfp version is ≥ 3
setup handling routines only once, use fpu_setup instead of fpu_init
Be more verbose about detected FPU hw.

File:

• kernel/arch/arm32/src/fpu_context.c (modified) (2 diffs)

kernel/arch/arm32/src/fpu_context.c

@@ -143 +143 @@
 void fpu_init(void)
 {
+}
+
+void fpu_setup(void)
+{
         uint32_t fpsid = 0;
-        uint32_t mvfr0 = 0;
         asm volatile (
                 "vmrs %0,fpsid\n"
-                "vmrs %1,mvfr0\n"
-                :"=r"(fpsid), "=r"(mvfr0)::
-        );
-        //TODO: Identify FPU unit
-        //and set correct functions to save/restore ctx
+                :"=r"(fpsid)::
+        );
         switch (FPSID_SUBACHITECTURE(fpsid))
         {
         case FPU_VFPv1:
+                printf("Detected VFPv1\n");
                 save_context = fpu_context_save_s32;
                 restore_context = fpu_context_restore_s32;
                 break;
         case FPU_VFPv2_COMMONv1:
+                printf("Detected VFPv2\n");
                 save_context = fpu_context_save_d16;
                 restore_context = fpu_context_restore_d16;
@@ -164 +166 @@
         case FPU_VFPv3_COMMONv2:
         case FPU_VFPv3_NOTRAP:
-        case FPU_VFPv3:
+        case FPU_VFPv3: {
+                uint32_t mvfr0 = 0;
+                asm volatile (
+                        "vmrs %0,mvfr0\n"
+                        :"=r"(mvfr0)::
+                );
                 /* See page B4-1637 */
                 if ((mvfr0 & 0xf) == 0x1) {
+                        printf("Detected VFPv3+ with 32 regs\n");
                         save_context = fpu_context_save_d32;
                         restore_context = fpu_context_restore_d32;
                 } else {
+                        printf("Detected VFPv3+ with 16 regs\n");
                         save_context = fpu_context_save_d16;
                         restore_context = fpu_context_restore_d16;
                 }
                 break;
+        }
 
         }