bootstage: Store boot timings in device tree

Add an option, CONFIG_BOOTSTAGE_FDT to pass boot timings to the kernel
in the device tree, if available. To use this, you must have
CONFIG_OF_LIBFDT defined.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/README b/README
index af76b0ccbfbcd8de8cb9c373555d57e869faf948..5e00fcc36cb0d069d3d3acb9283c654f64023069 100644 (file)
--- a/README
+++ b/README
@@ -2384,6 +2384,27 @@ The following options need to be configured:
                 29,916,167 26,005,792  bootm_start
                 30,361,327    445,160  start_kernel
 
+               CONFIG_BOOTSTAGE_FDT
+               Stash the bootstage information in the FDT. A root 'bootstage'
+               node is created with each bootstage id as a child. Each child
+               has a 'name' property and either 'mark' containing the
+               mark time in microsecond, or 'accum' containing the
+               accumulated time for that bootstage id in microseconds.
+               For example:
+
+               bootstage {
+                       154 {
+                               name = "board_init_f";
+                               mark = <3575678>;
+                       };
+                       170 {
+                               name = "lcd";
+                               accum = <33482>;
+                       };
+               };
+
+               Code in the Linux kernel can find this in /proc/devicetree.
+
 Legacy uImage format:
 
   Arg  Where                   When

diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 599547d2c8a3b2cf5b825203e93fd408d14dba2a..8d5bc589fcbdc69e89a12a4b791eb39604351932 100644 (file)
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -96,6 +96,9 @@ static void announce_and_cleanup(void)
 {
        printf("\nStarting kernel ...\n\n");
        bootstage_mark_name(BOOTSTAGE_ID_BOOTM_HANDOFF, "start_kernel");
+#ifdef CONFIG_BOOTSTAGE_FDT
+       bootstage_fdt_add_report();
+#endif
 #ifdef CONFIG_BOOTSTAGE_REPORT
        bootstage_report();
 #endif

diff --git a/common/bootstage.c b/common/bootstage.c
index e7c3fa887144cdee9762bdcc0c44219c7974a2a4..9ea0128aa6e0b6d837f11051043ab187feb21aeb 100644 (file)
--- a/common/bootstage.c
+++ b/common/bootstage.c
@@ -124,9 +124,32 @@ static void print_time(unsigned long us_time)
        }
 }
 
+/**
+ * Get a record name as a printable string
+ *
+ * @param buf  Buffer to put name if needed
+ * @param len  Length of buffer
+ * @param rec  Boot stage record to get the name from
+ * @return pointer to name, either from the record or pointing to buf.
+ */
+static const char *get_record_name(char *buf, int len,
+                                  struct bootstage_record *rec)
+{
+       if (rec->name)
+               return rec->name;
+       else if (rec->id >= BOOTSTAGE_ID_USER)
+               snprintf(buf, len, "user_%d", rec->id - BOOTSTAGE_ID_USER);
+       else
+               snprintf(buf, len, "id=%d", rec->id);
+
+       return buf;
+}
+
 static uint32_t print_time_record(enum bootstage_id id,
                        struct bootstage_record *rec, uint32_t prev)
 {
+       char buf[20];
+
        if (prev == -1U) {
                printf("%11s", "");
                print_time(rec->time_us);
@@ -134,12 +157,8 @@ static uint32_t print_time_record(enum bootstage_id id,
                print_time(rec->time_us);
                print_time(rec->time_us - prev);
        }
-       if (rec->name)
-               printf("  %s\n", rec->name);
-       else if (id >= BOOTSTAGE_ID_USER)
-               printf("  user_%d\n", id - BOOTSTAGE_ID_USER);
-       else
-               printf("  id=%d\n", id);
+       printf("  %s\n", get_record_name(buf, sizeof(buf), rec));
+
        return rec->time_us;
 }
 
@@ -150,6 +169,70 @@ static int h_compare_record(const void *r1, const void *r2)
        return rec1->time_us > rec2->time_us ? 1 : -1;
 }
 
+#ifdef CONFIG_OF_LIBFDT
+/**
+ * Add all bootstage timings to a device tree.
+ *
+ * @param blob Device tree blob
+ * @return 0 on success, != 0 on failure.
+ */
+static int add_bootstages_devicetree(struct fdt_header *blob)
+{
+       int bootstage;
+       char buf[20];
+       int id;
+       int i;
+
+       if (!blob)
+               return 0;
+
+       /*
+        * Create the node for bootstage.
+        * The address of flat device tree is set up by the command bootm.
+        */
+       bootstage = fdt_add_subnode(blob, 0, "bootstage");
+       if (bootstage < 0)
+               return -1;
+
+       /*
+        * Insert the timings to the device tree in the reverse order so
+        * that they can be printed in the Linux kernel in the right order.
+        */
+       for (id = BOOTSTAGE_ID_COUNT - 1, i = 0; id >= 0; id--, i++) {
+               struct bootstage_record *rec = &record[id];
+               int node;
+
+               if (id != BOOTSTAGE_ID_AWAKE && rec->time_us == 0)
+                       continue;
+
+               node = fdt_add_subnode(blob, bootstage, simple_itoa(i));
+               if (node < 0)
+                       break;
+
+               /* add properties to the node. */
+               if (fdt_setprop_string(blob, node, "name",
+                               get_record_name(buf, sizeof(buf), rec)))
+                       return -1;
+
+               /* Check if this is a 'mark' or 'accum' record */
+               if (fdt_setprop_cell(blob, node,
+                               rec->start_us ? "accum" : "mark",
+                               rec->time_us))
+                       return -1;
+       }
+
+       return 0;
+}
+
+int bootstage_fdt_add_report(void)
+{
+       if (add_bootstages_devicetree(working_fdt))
+               puts("bootstage: Failed to add to device tree\n");
+
+       return 0;
+}
+#endif
+
 void bootstage_report(void)
 {
        struct bootstage_record *rec = record;

diff --git a/include/bootstage.h b/include/bootstage.h
index 127c94f1b25e25e51325c16f4ecf38ec190729a4..9113852ca26f57a10a7595d4b58cf2a5af123447 100644 (file)
--- a/include/bootstage.h
+++ b/include/bootstage.h
@@ -277,6 +277,13 @@ uint32_t bootstage_accum(enum bootstage_id id);
 /* Print a report about boot time */
 void bootstage_report(void);
 
+/**
+ * Add bootstage information to the device tree
+ *
+ * @return 0 if ok, -ve on error
+ */
+int bootstage_fdt_add_report(void);
+
 #else
 /*
  * This is a dummy implementation which just calls show_boot_progress(),