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Debug timer_mtimer_cold_init() in OpenSBI

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This commit is contained in:
Rodrigo Arias 2024-07-12 13:47:01 +02:00
parent 722f185525
commit 6576a92ba5
2 changed files with 108 additions and 0 deletions
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51
JOURNAL.md
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@ -1623,3 +1623,54 @@ These G's must be coming from the bootrom.
So let's go back to the generic platform and place some `printf()` calls to
determine where it is failing.
OpenSBI v1.5
____ _____ ____ _____
/ __ \ / ____| _ \_ _|
| | | |_ __ ___ _ __ | (___ | |_) || |
| | | | '_ \ / _ \ '_ \ \___ \| _ < | |
| |__| | |_) | __/ | | |____) | |_) || |_
\____/| .__/ \___|_| |_|_____/|____/_____|
| |
|_|
sbi_timer_init: begins
sbi_timer_init: got Zicntr extension
fdt_timer_cold_init: pos = 0
fdt_timer_cold_init: got match, name = riscv,clint0
fdt_timer_cold_init: enabled
fdt_timer_cold_init: drc->cold_init = -3
fdt_timer_init: fdt_timer_cold_init failed (-3)
sbi_platform_timer: sbi_platform_timer_init failed (-3)
init_coldboot: timer init failed (error -3)
Okay, now we can see where it failed. I wonder why aren't these messages enabled
by default. I'll guess this is the `timer_mtimer_cold_init()` function, so let's
add some more instrumentation there.
It seems that SiFive timer has a very long weird offset:
if (is_clint) { /* SiFive CLINT */
/* Set CLINT addresses */
mt->mtimecmp_addr = addr[0] + ACLINT_DEFAULT_MTIMECMP_OFFSET;
mt->mtimecmp_size = ACLINT_DEFAULT_MTIMECMP_SIZE;
if (!quirks->clint_without_mtime) {
mt->mtime_addr = addr[0] + ACLINT_DEFAULT_MTIME_OFFSET;
mt->mtime_size = size[0] - mt->mtimecmp_size;
/* Adjust MTIMER address and size for CLINT device */
mt->mtime_addr += quirks->clint_mtime_offset;
mt->mtime_size -= quirks->clint_mtime_offset;
} else {
mt->mtime_addr = mt->mtime_size = 0;
}
mt->mtimecmp_addr += quirks->clint_mtime_offset;
} else { /* RISC-V ACLINT MTIMER */
/* Set ACLINT MTIMER addresses */
mt->mtime_addr = addr[0];
mt->mtime_size = size[0];
mt->mtimecmp_addr = addr[1];
mt->mtimecmp_size = size[1];
}
We may want to use the ACLINT timer instead. Let's first see where the addresses
lay in memory, and then use that to verify we change it to 0x0 and 0x8.

57
opensbi-timer-debug.patch
View File

@ -98,3 +98,60 @@ index f468730..db20526 100644
+
+ return rc;
}
diff --git a/lib/utils/timer/fdt_timer_mtimer.c b/lib/utils/timer/fdt_timer_mtimer.c
index 9e27e3a..fba48ca 100644
--- a/lib/utils/timer/fdt_timer_mtimer.c
+++ b/lib/utils/timer/fdt_timer_mtimer.c
@@ -8,6 +8,7 @@
*/
#include <libfdt.h>
+#include <sbi/sbi_console.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_heap.h>
#include <sbi/sbi_list.h>
@@ -33,6 +34,7 @@ static struct aclint_mtimer_data *mt_reference = NULL;
static int timer_mtimer_cold_init(void *fdt, int nodeoff,
const struct fdt_match *match)
{
+
int rc;
unsigned long addr[2], size[2];
struct timer_mtimer_node *mtn, *n;
@@ -40,6 +42,8 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
const struct timer_mtimer_quirks *quirks = match->data;
bool is_clint = quirks && quirks->is_clint;
+ sbi_printf("timer_mtimer_cold_init: begins, is_clint = %d\n", (int) is_clint);
+
mtn = sbi_zalloc(sizeof(*mtn));
if (!mtn)
return SBI_ENOMEM;
@@ -49,6 +53,7 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
&addr[0], &size[0], &addr[1], &size[1],
&mt->first_hartid, &mt->hart_count);
if (rc) {
+ sbi_printf("timer_mtimer_cold_init: fdt_parse_aclint_node failed (%d)\n", rc);
sbi_free(mtn);
return rc;
}
@@ -57,6 +62,7 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
rc = fdt_parse_timebase_frequency(fdt, &mt->mtime_freq);
if (rc) {
+ sbi_printf("timer_mtimer_cold_init: fdt_parse_timebase_frequency failed (%d)\n", rc);
sbi_free(mtn);
return rc;
}
@@ -83,6 +89,11 @@ static int timer_mtimer_cold_init(void *fdt, int nodeoff,
mt->mtimecmp_size = size[1];
}
+ sbi_printf("timer_mtimer_cold_init: mtime_addr = 0x%08lx\n", mt->mtime_addr);
+ sbi_printf("timer_mtimer_cold_init: mtime_size = 0x%08lx\n", mt->mtime_size);
+ sbi_printf("timer_mtimer_cold_init: mtime_addr = 0x%08lx\n", mt->mtimecmp_addr);
+ sbi_printf("timer_mtimer_cold_init: mtime_addr = 0x%08lx\n", mt->mtimecmp_size);
+
/* Apply additional quirks */
if (quirks) {
mt->has_64bit_mmio = quirks->has_64bit_mmio;