Diff: source/family/freescale/target_reset_Lseries.c

Revision:

0:01f31e923fe2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/family/freescale/target_reset_Lseries.c	Tue Apr 07 12:55:42 2020 +0200
@@ -0,0 +1,137 @@
+/**
+ * @file    target_reset_Lseries.c
+ * @brief   Target reset for the Kinetis L series
+ *
+ * DAPLink Interface Firmware
+ * Copyright (c) 2009-2019, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "swd_host.h"
+#include "info.h"
+#include "target_family.h"
+
+#define MDM_STATUS  0x01000000
+#define MDM_CTRL    0x01000004     //
+#define MDM_IDR     0x010000fc     // read-only identification register
+#define MDM_ID      0x001c0020     // L series
+
+static void target_before_init_debug(void)
+{
+    swd_set_target_reset(1);
+}
+
+static uint8_t target_unlock_sequence(void)
+{
+    uint32_t val;
+
+    // read the device ID
+    if (!swd_read_ap(MDM_IDR, &val)) {
+        return 0;
+    }
+
+    // verify the result
+    if (val != MDM_ID) {
+        return 0;
+    }
+
+    if (!swd_read_ap(MDM_STATUS, &val)) {
+        return 0;
+    }
+
+    // flash in secured mode
+    if (val & (1 << 2)) {
+        // hold the device in reset
+        swd_set_target_reset(1);
+
+        // write the mass-erase enable bit
+        if (!swd_write_ap(MDM_CTRL, 1)) {
+            return 0;
+        }
+
+        while (1) {
+            // wait until mass erase is started
+            if (!swd_read_ap(MDM_STATUS, &val)) {
+                return 0;
+            }
+
+            if (val & 1) {
+                break;
+            }
+        }
+
+        // mass erase in progress
+        while (1) {
+            // keep reading until procedure is complete
+            if (!swd_read_ap(MDM_CTRL, &val)) {
+                return 0;
+            }
+
+            if (val == 0) {
+                break;
+            }
+        }
+    }
+
+    return 1;
+}
+
+// Check Flash Configuration Field bytes at address 0x400-0x40f to ensure that flash security
+// won't be enabled.
+//
+// FCF bytes:
+// [0x0-0x7]=backdoor key
+// [0x8-0xb]=flash protection bytes
+// [0xc]=FSEC:
+//      [7:6]=KEYEN (2'b10 is backdoor key enabled, all others backdoor key disabled)
+//      [5:4]=MEEN (2'b10 mass erase disabled, all other mass erase enabled)
+//      [3:2]=FSLACC (2'b00 and 2'b11 factory access enabled, 2'b01 and 2'b10 factory access disabled)
+//      [1:0]=SEC (2'b10 flash security disabled, all other flash security enabled)
+// [0xd]=FOPT
+// [0xe]=EEPROM protection bytes (FlexNVM devices only)
+// [0xf]=data flash protection bytes (FlexNVM devices only)
+//
+// This function checks that:
+// - FSEC does not disable mass erase or secure the device.
+//
+uint8_t static security_bits_set(uint32_t addr, uint8_t *data, uint32_t size)
+{
+    const uint32_t fsec_addr = 0x40C;
+
+    if ((addr <= fsec_addr) && (addr + size) > fsec_addr) {
+        uint8_t fsec = data[fsec_addr - addr];
+
+        // make sure we can unsecure the device or dont program at all
+        if ((fsec & 0x30) == 0x20) {
+            // Dont allow programming mass-erase disabled state
+            return 1;
+        }
+
+        // Security is OK long as we can mass-erase (comment the following out to enable target security)
+        if ((fsec & 0x03) != 0x02) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+const target_family_descriptor_t g_nxp_kinetis_lseries = {
+    .family_id = kNXP_KinetisL_FamilyID,
+    .default_reset_type = kHardwareReset,
+    .target_before_init_debug = target_before_init_debug,
+    .target_unlock_sequence = target_unlock_sequence,
+    .security_bits_set = security_bits_set,
+};