armv7m: detect floating point feature

This patch add fp feature detection on cortex-m4.

Change-Id: I99e9d1bf5534630a22b8ad9c878165683db2d0ba
Signed-off-by: Mathias K <kesmtp@freenet.de>
Reviewed-on: http://openocd.zylin.com/524
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

diff --git a/src/target/armv7m.c b/src/target/armv7m.c
index 258653eba716ed9da713f1ecc3035aad748584d9..780e81b5baf92dca1f7b5313639e04ca0acb712e 100644 (file)
--- a/src/target/armv7m.c
+++ b/src/target/armv7m.c
@@ -578,6 +578,7 @@ int armv7m_init_arch_info(struct target *target, struct armv7m_common *armv7m)
        struct arm *arm = &armv7m->arm;
 
        armv7m->common_magic = ARMV7M_COMMON_MAGIC;
+       armv7m->fp_feature = FP_NONE;
 
        arm->core_type = ARM_MODE_THREAD;
        arm->arch_info = armv7m;

diff --git a/src/target/armv7m.h b/src/target/armv7m.h
index 35bd62a6f217051b0513b38440321ecc9b1da881..827a87993846bdf65fe2a9993fa8c24c36f211a4 100644 (file)
--- a/src/target/armv7m.h
+++ b/src/target/armv7m.h
@@ -97,6 +97,11 @@ enum {
        ARMV7M_LAST_REG,
 };
 
+enum {
+       FP_NONE = 0,
+       FPv4_SP,
+};
+
 #define ARMV7M_COMMON_MAGIC 0x2A452A45
 
 struct armv7m_common {
@@ -108,6 +113,8 @@ struct armv7m_common {
        int exception_number;
        struct adiv5_dap dap;
 
+       int fp_feature;
+
        uint32_t demcr;
 
        /* Direct processor core register read and writes */

diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index 76e197c116d904fe8c2fb046138b818363986f12..488899cbe9430ac814db859efb9219bc2d0d38d5 100644 (file)
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -1756,13 +1756,20 @@ fail1:
         */
 }
 
+#define MVFR0 0xe000ef40
+#define MVFR1 0xe000ef44
+
+#define MVFR0_DEFAULT_M4 0x10110021
+#define MVFR1_DEFAULT_M4 0x11000011
+
 int cortex_m3_examine(struct target *target)
 {
        int retval;
-       uint32_t cpuid, fpcr;
+       uint32_t cpuid, fpcr, mvfr0, mvfr1;
        int i;
        struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
        struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
+       struct armv7m_common *armv7m = target_to_armv7m(target);
 
        retval = ahbap_debugport_init(swjdp);
        if (retval != ERROR_OK)
@@ -1783,6 +1790,17 @@ int cortex_m3_examine(struct target *target)
                                i, (uint8_t)((cpuid >> 20) & 0xf), (uint8_t)((cpuid >> 0) & 0xf));
                LOG_DEBUG("cpuid: 0x%8.8" PRIx32 "", cpuid);
 
+               /* test for floating point feature on cortex-m4 */
+               if (i == 4) {
+                       target_read_u32(target, MVFR0, &mvfr0);
+                       target_read_u32(target, MVFR1, &mvfr1);
+
+                       if ((mvfr0 == MVFR0_DEFAULT_M4) && (mvfr1 == MVFR1_DEFAULT_M4)) {
+                               LOG_DEBUG("Cortex-M%d floating point feature FPv4_SP found", i);
+                               armv7m->fp_feature = FPv4_SP;
+                       }
+               }
+
                /* NOTE: FPB and DWT are both optional. */
 
                /* Setup FPB */