Adapt log buffer code to support Linux 2.6

A new environment variable, "logversion", selects the log buffer
behaviour. If it is not set or set to a value other than 2, then the
old, Linux 2.4.4, behaviour is selected.

Signed-off-by: Igor Lisitsin <igor@emcraft.com>
--

diff --git a/common/cmd_log.c b/common/cmd_log.c
index 042a403026f00fa04b5cadd571ee3246b301d522..5bf811e75580e2842c0c323ddceb118fbfeb2ee3 100644 (file)
--- a/common/cmd_log.c
+++ b/common/cmd_log.c
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2002
+ * (C) Copyright 2002-2007
  * Detlev Zundel, DENX Software Engineering, dzu@denx.de.
  *
  * Code used from linux/kernel/printk.c
@@ -60,45 +60,40 @@ static char buf[1024];
 /* This combination will not print messages with the default loglevel */
 static unsigned console_loglevel = 3;
 static unsigned default_message_loglevel = 4;
-static unsigned char *log_buf = NULL;
-static unsigned long *ext_log_size;
-static unsigned long *ext_log_start;
-static unsigned long *ext_logged_chars;
-#define log_size (*ext_log_size)
-#define log_start (*ext_log_start)
-#define logged_chars (*ext_logged_chars)
+static unsigned log_version = 1;
+static logbuff_t *log;
 
-/* Forced by code, eh! */
-#define LOGBUFF_MAGIC 0xc0de4ced
-
-/* The mapping used here has to be the same as in setup_ext_logbuff ()
-   in linux/kernel/printk */
 void logbuff_init_ptrs (void)
 {
-       unsigned long *ext_tag;
-       unsigned long post_word;
+       unsigned long tag, post_word;
        char *s;
 
-       log_buf = (unsigned char *)(gd->bd->bi_memsize-LOGBUFF_LEN);
-       ext_tag = (unsigned long *)(log_buf)-4;
-       ext_log_start = (unsigned long *)(log_buf)-3;
-       ext_log_size = (unsigned long *)(log_buf)-2;
-       ext_logged_chars = (unsigned long *)(log_buf)-1;
+       log = (logbuff_t *)(gd->bd->bi_memsize-LOGBUFF_LEN) - 1;
+
+       /* Set up log version */
+       if ((s = getenv ("logversion")) != NULL)
+               log_version = (int)simple_strtoul (s, NULL, 10);
+
+       if (log_version == 2)
+               tag = log->v2.tag;
+       else
+               tag = log->v1.tag;
        post_word = post_word_load();
 #ifdef CONFIG_POST
        /* The post routines have setup the word so we can simply test it */
-       if (post_word_load () & POST_COLDBOOT) {
-               logged_chars = log_size = log_start = 0;
-               *ext_tag = LOGBUFF_MAGIC;
+       if (tag != LOGBUFF_MAGIC || (post_word & POST_COLDBOOT)) {
+               logbuff_reset ();
        }
 #else
        /* No post routines, so we do our own checking                    */
-       if (post_word != LOGBUFF_MAGIC) {
-               logged_chars = log_size = log_start = 0;
+       if (tag != LOGBUFF_MAGIC || post_word != LOGBUFF_MAGIC) {
+               logbuff_reset ();
                post_word_store (LOGBUFF_MAGIC);
-               *ext_tag = LOGBUFF_MAGIC;
        }
 #endif
+       if (log_version == 2 && (long)log->v2.start > (long)log->v2.con)
+               log->v2.start = log->v2.con;
+
        /* Initialize default loglevel if present */
        if ((s = getenv ("loglevel")) != NULL)
                console_loglevel = (int)simple_strtoul (s, NULL, 10);
@@ -106,6 +101,15 @@ void logbuff_init_ptrs (void)
        gd->post_log_word |= LOGBUFF_INITIALIZED;
 }
 
+void logbuff_reset (void)
+{
+       memset (log, 0, sizeof (logbuff_t));
+       if (log_version == 2)
+               log->v2.tag = LOGBUFF_MAGIC;
+       else
+               log->v1.tag = LOGBUFF_MAGIC;
+}
+
 int drv_logbuff_init (void)
 {
        device_t logdev;
@@ -162,7 +166,7 @@ void logbuff_log(char *msg)
 int do_log (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 {
        char *s;
-       unsigned long i;
+       unsigned long i, start, size;
 
        if (strcmp(argv[1],"append") == 0) {
                /* Log concatenation of all arguments separated by spaces */
@@ -177,21 +181,34 @@ int do_log (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 
        case 2:
                if (strcmp(argv[1],"show") == 0) {
-                       for (i=0; i < (log_size&LOGBUFF_MASK); i++) {
-                               s = (char *)log_buf+((log_start+i)&LOGBUFF_MASK);
+                       if (log_version == 2) {
+                               start = log->v2.start;
+                               size = log->v2.end - log->v2.start;
+                       }
+                       else {
+                               start = log->v1.start;
+                               size = log->v1.size;
+                       }
+                       for (i=0; i < (size&LOGBUFF_MASK); i++) {
+                               s = (char *)log->buf+((start+i)&LOGBUFF_MASK);
                                putc (*s);
                        }
                        return 0;
                } else if (strcmp(argv[1],"reset") == 0) {
-                       log_start    = 0;
-                       log_size     = 0;
-                       logged_chars = 0;
+                       logbuff_reset ();
                        return 0;
                } else if (strcmp(argv[1],"info") == 0) {
-                       printf ("Logbuffer   at  %08lx\n", (unsigned long)log_buf);
-                       printf ("log_start    =  %08lx\n", log_start);
-                       printf ("log_size     =  %08lx\n", log_size);
-                       printf ("logged_chars =  %08lx\n", logged_chars);
+                       printf ("Logbuffer   at  %08lx\n", (unsigned long)log->buf);
+                       if (log_version == 2) {
+                               printf ("log_start    =  %08lx\n", log->v2.start);
+                               printf ("log_end      =  %08lx\n", log->v2.end);
+                               printf ("logged_chars =  %08lx\n", log->v2.chars);
+                       }
+                       else {
+                               printf ("log_start    =  %08lx\n", log->v1.start);
+                               printf ("log_size     =  %08lx\n", log->v1.size);
+                               printf ("logged_chars =  %08lx\n", log->v1.chars);
+                       }
                        return 0;
                }
                printf ("Usage:\n%s\n", cmdtp->usage);
@@ -202,7 +219,7 @@ int do_log (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
                return 1;
        }
 }
-#if defined(CONFIG_LOGBUFFER)
+
 U_BOOT_CMD(
        log,     255,   1,      do_log,
        "log     - manipulate logbuffer\n",
@@ -211,7 +228,7 @@ U_BOOT_CMD(
        "log show   - show contents\n"
        "log append <msg> - append <msg> to the logbuffer\n"
 );
-#endif /* CONFIG_LOGBUFFER */
+
 static int logbuff_printk(const char *line)
 {
        int i;
@@ -241,13 +258,22 @@ static int logbuff_printk(const char *line)
                }
                line_feed = 0;
                for (; p < buf_end; p++) {
-                       log_buf[(log_start+log_size) & LOGBUFF_MASK] = *p;
-                       if (log_size < LOGBUFF_LEN)
-                               log_size++;
-                       else
-                               log_start++;
-
-                       logged_chars++;
+                       if (log_version == 2) {
+                               log->buf[log->v2.end & LOGBUFF_MASK] = *p;
+                               log->v2.end++;
+                               if (log->v2.end - log->v2.start > LOGBUFF_LEN)
+                                       log->v2.start++;
+                               log->v2.chars++;
+                       }
+                       else {
+                               log->buf[(log->v1.start + log->v1.size) &
+                                        LOGBUFF_MASK] = *p;
+                               if (log->v1.size < LOGBUFF_LEN)
+                                       log->v1.size++;
+                               else
+                                       log->v1.start++;
+                               log->v1.chars++;
+                       }
                        if (*p == '\n') {
                                line_feed = 1;
                                break;

diff --git a/include/logbuff.h b/include/logbuff.h
index 3acfc18a78272ea1a7aeef49510b8861244ea2af..d4157290538c1baf1433a5846469055712efd059 100644 (file)
--- a/include/logbuff.h
+++ b/include/logbuff.h
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2002
+ * (C) Copyright 2002-2007
  * Detlev Zundel, dzu@denx.de.
  *
  * See file CREDITS for list of people who contributed to this
@@ -25,6 +25,7 @@
 
 #ifdef CONFIG_LOGBUFFER
 
+#define LOGBUFF_MAGIC  0xc0de4ced      /* Forced by code, eh!  */
 #define LOGBUFF_LEN    (16384) /* Must be 16k right now */
 #define LOGBUFF_MASK   (LOGBUFF_LEN-1)
 #define LOGBUFF_OVERHEAD (4096) /* Logbuffer overhead for extra info */
@@ -32,6 +33,29 @@
 
 #define LOGBUFF_INITIALIZED    (1<<31)
 
+/* The mapping used here has to be the same as in setup_ext_logbuff ()
+   in linux/kernel/printk */
+
+typedef struct {
+       union {
+               struct {
+                       unsigned long   tag;
+                       unsigned long   start;
+                       unsigned long   con;
+                       unsigned long   end;
+                       unsigned long   chars;
+               } v2;
+               struct {
+                       unsigned long   dummy;
+                       unsigned long   tag;
+                       unsigned long   start;
+                       unsigned long   size;
+                       unsigned long   chars;
+               } v1;
+       };
+       unsigned char   buf[0];
+} logbuff_t;
+
 int drv_logbuff_init (void);
 void logbuff_init_ptrs (void);
 void logbuff_log(char *msg);