github.com/antonblanchard.microwatt
1
0
Fork 0
mirror of https://github.com/antonblanchard/microwatt.git synced 2026-05-05 07:44:16 +00:00
Code Releases Activity

Add core logging

Browse Source 
This logs 256 bits of data per cycle to a ring buffer in BRAM.  The
data collected can be read out through 2 new SPRs or through the
debug interface.

The new SPRs are LOG_ADDR (724) and LOG_DATA (725).  LOG_ADDR contains
the buffer write pointer in the upper 32 bits (in units of entries,
i.e. 32 bytes) and the read pointer in the lower 32 bits (in units of
doublewords, i.e. 8 bytes).  Reading LOG_DATA gives the doubleword
from the buffer at the read pointer and increments the read pointer.
Setting bit 31 of LOG_ADDR inhibits the trace log system from writing
to the log buffer, so the contents are stable and can be read.

There are two new debug addresses which function similarly to the
LOG_ADDR and LOG_DATA SPRs.  The log is frozen while either or both of
the LOG_ADDR SPR bit 31 or the debug LOG_ADDR register bit 31 are set.

The buffer defaults to 2048 entries, i.e. 64kB.  The size is set by
the LOG_LENGTH generic on the core_debug module.  Software can
determine the length of the buffer because the length is ORed into the
buffer write pointer in the upper 32 bits of LOG_ADDR.  Hence the
length of the buffer can be calculated as 1 << (31 - clz(LOG_ADDR)).

There is a program to format the log entries in a somewhat readable
fashion in scripts/fmt_log/fmt_log.c.  The log_entry struct in that
file describes the layout of the bits in the log entries.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This commit is contained in:
Paul Mackerras
2020-05-14 13:25:48 +10:00
parent aab84acda8
commit 49a4d9f67a
14 changed files with 671 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

87
scripts/mw_debug/mw_debug.c
View File

@@ -42,6 +42,9 @@
#define DBG_CORE_GSPR_INDEX 0x14
#define DBG_CORE_GSPR_DATA 0x15
#define DBG_LOG_ADDR 0x16
#define DBG_LOG_DATA 0x17
static bool debug;
struct backend {
@@ -548,6 +551,73 @@ static void save(const char *filename, uint64_t addr, uint64_t size)
printf("%x done.\n", count);
}
#define LOG_STOP 0x80000000ull
static void log_start(void)
{
check(dmi_write(DBG_LOG_ADDR, 0), "writing LOG_ADDR");
}
static void log_stop(void)
{
uint64_t lsize, laddr, waddr;
check(dmi_write(DBG_LOG_ADDR, LOG_STOP), "writing LOG_ADDR");
check(dmi_read(DBG_LOG_ADDR, &laddr), "reading LOG_ADDR");
waddr = laddr >> 32;
for (lsize = 1; lsize; lsize <<= 1)
if ((waddr >> 1) < lsize)
break;
waddr &= ~lsize;
printf("Log size = %" PRIu64 " entries, ", lsize);
printf("write ptr = %" PRIx64 "\n", waddr);
}
static void log_dump(const char *filename)
{
FILE *f;
uint64_t lsize, laddr, waddr;
uint64_t orig_laddr;
uint64_t i, ldata;
f = fopen(filename, "w");
if (f == NULL) {
fprintf(stderr, "Failed to create '%s': %s\n", filename,
strerror(errno));
exit(1);
}
check(dmi_read(DBG_LOG_ADDR, &orig_laddr), "reading LOG_ADDR");
if (!(orig_laddr & LOG_STOP))
check(dmi_write(DBG_LOG_ADDR, LOG_STOP), "writing LOG_ADDR");
waddr = orig_laddr >> 32;
for (lsize = 1; lsize; lsize <<= 1)
if ((waddr >> 1) < lsize)
break;
waddr &= ~lsize;
printf("Log size = %" PRIu64 " entries\n", lsize);
laddr = LOG_STOP | (waddr << 2);
check(dmi_write(DBG_LOG_ADDR, laddr), "writing LOG_ADDR");
for (i = 0; i < lsize * 4; ++i) {
check(dmi_read(DBG_LOG_DATA, &ldata), "reading LOG_DATA");
if (fwrite(&ldata, sizeof(ldata), 1, f) != 1) {
fprintf(stderr, "Write error on %s\n", filename);
exit(1);
}
if (!(i % 128)) {
printf("%" PRIu64 "...\r", i * 8);
fflush(stdout);
}
}
fclose(f);
printf("%" PRIu64 " done\n", lsize * 32);
check(dmi_write(DBG_LOG_ADDR, orig_laddr), "writing LOG_ADDR");
}
static void usage(const char *cmd)
{
fprintf(stderr, "Usage: %s -b <jtag|sim> <command> <args>\n", cmd);
@@ -572,6 +642,12 @@ static void usage(const char *cmd)
fprintf(stderr, " gpr <reg> [count]\n");
fprintf(stderr, " status\n");
fprintf(stderr, "\n");
fprintf(stderr, " Core logging:\n");
fprintf(stderr, " lstart start logging\n");
fprintf(stderr, " lstop stop logging\n");
fprintf(stderr, " ldump <file> dump log to file\n");
fprintf(stderr, "\n");
fprintf(stderr, " JTAG:\n");
fprintf(stderr, " dmiread <hex addr>\n");
@@ -710,6 +786,17 @@ int main(int argc, char *argv[])
if (((i+1) < argc) && isdigit(argv[i+1][0]))
count = strtoul(argv[++i], NULL, 10);
gpr_read(reg, count);
} else if (strcmp(argv[i], "lstart") == 0) {
log_start();
} else if (strcmp(argv[i], "lstop") == 0) {
log_stop();
} else if (strcmp(argv[i], "ldump") == 0) {
const char *filename;
if ((i+1) >= argc)
usage(argv[0]);
filename = argv[++i];
log_dump(filename);
} else {
fprintf(stderr, "Unknown command %s\n", argv[i]);
exit(1);