bootstage: Add feature to stash/unstash bootstage info

It is useful to be able to write the bootstage information to memory for
use by a later utility, or the Linux kernel. Provide a function to do
this as well as a function to read bootstage information back and incorporate
it into the current table.

This also makes it possible for U-Boot to chain to another U-Boot and pass
on its bootstage information.

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

diff --git a/common/bootstage.c b/common/bootstage.c
index 9ea0128aa6e0b6d837f11051043ab187feb21aeb..a1e09394cc5ba7818dae77893c1c2175b5b7bdb3 100644 (file)
--- a/common/bootstage.c
+++ b/common/bootstage.c
@@ -44,6 +44,18 @@ struct bootstage_record {
 static struct bootstage_record record[BOOTSTAGE_ID_COUNT] = { {1} };
 static int next_id = BOOTSTAGE_ID_USER;
 
+enum {
+       BOOTSTAGE_VERSION       = 0,
+       BOOTSTAGE_MAGIC         = 0xb00757a3,
+};
+
+struct bootstage_hdr {
+       uint32_t version;       /* BOOTSTAGE_VERSION */
+       uint32_t count;         /* Number of records */
+       uint32_t size;          /* Total data size (non-zero if valid) */
+       uint32_t magic;         /* Unused */
+};
+
 ulong bootstage_add_record(enum bootstage_id id, const char *name,
                           int flags, ulong mark)
 {
@@ -282,3 +294,150 @@ ulong __timer_get_boot_us(void)
 
 ulong timer_get_boot_us(void)
        __attribute__((weak, alias("__timer_get_boot_us")));
+
+/**
+ * Append data to a memory buffer
+ *
+ * Write data to the buffer if there is space. Whether there is space or not,
+ * the buffer pointer is incremented.
+ *
+ * @param ptrp Pointer to buffer, updated by this function
+ * @param end  Pointer to end of buffer
+ * @param data Data to write to buffer
+ * @param size Size of data
+ */
+static void append_data(char **ptrp, char *end, const void *data, int size)
+{
+       char *ptr = *ptrp;
+
+       *ptrp += size;
+       if (*ptrp > end)
+               return;
+
+       memcpy(ptr, data, size);
+}
+
+int bootstage_stash(void *base, int size)
+{
+       struct bootstage_hdr *hdr = (struct bootstage_hdr *)base;
+       struct bootstage_record *rec;
+       char buf[20];
+       char *ptr = base, *end = ptr + size;
+       uint32_t count;
+       int id;
+
+       if (hdr + 1 > (struct bootstage_hdr *)end) {
+               debug("%s: Not enough space for bootstage hdr\n", __func__);
+               return -1;
+       }
+
+       /* Write an arbitrary version number */
+       hdr->version = BOOTSTAGE_VERSION;
+
+       /* Count the number of records, and write that value first */
+       for (rec = record, id = count = 0; id < BOOTSTAGE_ID_COUNT;
+                       id++, rec++) {
+               if (rec->time_us != 0)
+                       count++;
+       }
+       hdr->count = count;
+       hdr->size = 0;
+       hdr->magic = BOOTSTAGE_MAGIC;
+       ptr += sizeof(*hdr);
+
+       /* Write the records, silently stopping when we run out of space */
+       for (rec = record, id = 0; id < BOOTSTAGE_ID_COUNT; id++, rec++) {
+               if (rec->time_us != 0)
+                       append_data(&ptr, end, rec, sizeof(*rec));
+       }
+
+       /* Write the name strings */
+       for (rec = record, id = 0; id < BOOTSTAGE_ID_COUNT; id++, rec++) {
+               if (rec->time_us != 0) {
+                       const char *name;
+
+                       name = get_record_name(buf, sizeof(buf), rec);
+                       append_data(&ptr, end, name, strlen(name) + 1);
+               }
+       }
+
+       /* Check for buffer overflow */
+       if (ptr > end) {
+               debug("%s: Not enough space for bootstage stash\n", __func__);
+               return -1;
+       }
+
+       /* Update total data size */
+       hdr->size = ptr - (char *)base;
+       printf("Stashed %d records\n", hdr->count);
+
+       return 0;
+}
+
+int bootstage_unstash(void *base, int size)
+{
+       struct bootstage_hdr *hdr = (struct bootstage_hdr *)base;
+       struct bootstage_record *rec;
+       char *ptr = base, *end = ptr + size;
+       uint rec_size;
+       int id;
+
+       if (size == -1)
+               end = (char *)(~(uintptr_t)0);
+
+       if (hdr + 1 > (struct bootstage_hdr *)end) {
+               debug("%s: Not enough space for bootstage hdr\n", __func__);
+               return -1;
+       }
+
+       if (hdr->magic != BOOTSTAGE_MAGIC) {
+               debug("%s: Invalid bootstage magic\n", __func__);
+               return -1;
+       }
+
+       if (ptr + hdr->size > end) {
+               debug("%s: Bootstage data runs past buffer end\n", __func__);
+               return -1;
+       }
+
+       if (hdr->count * sizeof(*rec) > hdr->size) {
+               debug("%s: Bootstage has %d records needing %d bytes, but "
+                       "only %d bytes is available\n", __func__, hdr->count,
+                     hdr->count * sizeof(*rec), hdr->size);
+               return -1;
+       }
+
+       if (hdr->version != BOOTSTAGE_VERSION) {
+               debug("%s: Bootstage data version %#0x unrecognised\n",
+                     __func__, hdr->version);
+               return -1;
+       }
+
+       if (next_id + hdr->count > BOOTSTAGE_ID_COUNT) {
+               debug("%s: Bootstage has %d records, we have space for %d\n"
+                       "- please increase CONFIG_BOOTSTAGE_USER_COUNT\n",
+                     __func__, hdr->count, BOOTSTAGE_ID_COUNT - next_id);
+               return -1;
+       }
+
+       ptr += sizeof(*hdr);
+
+       /* Read the records */
+       rec_size = hdr->count * sizeof(*record);
+       memcpy(record + next_id, ptr, rec_size);
+
+       /* Read the name strings */
+       ptr += rec_size;
+       for (rec = record + next_id, id = 0; id < hdr->count; id++, rec++) {
+               rec->name = ptr;
+
+               /* Assume no data corruption here */
+               ptr += strlen(ptr) + 1;
+       }
+
+       /* Mark the records as read */
+       next_id += hdr->count;
+       printf("Unstashed %d records\n", hdr->count);
+
+       return 0;
+}

diff --git a/include/bootstage.h b/include/bootstage.h
index 9113852ca26f57a10a7595d4b58cf2a5af123447..d6b4e7b0d04f8c8dada87757336da2da9c8b210c 100644 (file)
--- a/include/bootstage.h
+++ b/include/bootstage.h
@@ -284,6 +284,27 @@ void bootstage_report(void);
  */
 int bootstage_fdt_add_report(void);
 
+/*
+ * Stash bootstage data into memory
+ *
+ * @param base Base address of memory buffer
+ * @param size Size of memory buffer
+ * @return 0 if stashed ok, -1 if out of space
+ */
+int bootstage_stash(void *base, int size);
+
+/**
+ * Read bootstage data from memory
+ *
+ * Bootstage data is read from memory and placed in the bootstage table
+ * in the user records.
+ *
+ * @param base Base address of memory buffer
+ * @param size Size of memory buffer (-1 if unknown)
+ * @return 0 if unstashed ok, -1 if bootstage info not found, or out of space
+ */
+int bootstage_unstash(void *base, int size);
+
 #else
 /*
  * This is a dummy implementation which just calls show_boot_progress(),
@@ -307,7 +328,15 @@ static inline ulong bootstage_mark_name(enum bootstage_id id, const char *name)
        return 0;
 }
 
+static inline int bootstage_stash(void *base, int size)
+{
+       return 0;       /* Pretend to succeed */
+}
 
+static inline int bootstage_unstash(void *base, int size)
+{
+       return 0;       /* Pretend to succeed */
+}
 #endif /* CONFIG_BOOTSTAGE */
 
 #endif