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Switch to "riscv,aclint-mtimer" timer

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This commit is contained in:
Rodrigo Arias 2024-07-12 13:55:08 +02:00
parent 6576a92ba5
commit 6a57dd004f
3 changed files with 44 additions and 4 deletions
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38
JOURNAL.md
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@ -1674,3 +1674,41 @@ It seems that SiFive timer has a very long weird offset:
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.
GGGGGGGGG
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
timer_mtimer_cold_init: begins, is_clint = 1
timer_mtimer_cold_init: mtime_addr = 0x4000dff8
timer_mtimer_cold_init: mtime_size = 0x000b4008
timer_mtimer_cold_init: mtime_addr = 0x40006000
timer_mtimer_cold_init: mtime_addr = 0x00007ff8
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)
Yeah, those addresses are not what we want. Based on the device tree, the clint
must be at 0x40002000, so they should be 40002000 and 40002008. Also I made some
typos in the printf command, this is the patch:
+ 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);
So, let's fix the patch and switch to the "riscv,aclint-mtimer" timer, which
doesn't set any quirk or weird offset.

6
opensbi-timer-debug.patch
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@ -99,7 +99,7 @@ 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
index 9e27e3a..cef2ee6 100644
--- a/lib/utils/timer/fdt_timer_mtimer.c
+++ b/lib/utils/timer/fdt_timer_mtimer.c
@@ -8,6 +8,7 @@
@ -149,8 +149,8 @@ index 9e27e3a..fba48ca 100644
+ 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);
+ sbi_printf("timer_mtimer_cold_init: mtimecmp_addr = 0x%08lx\n", mt->mtimecmp_addr);
+ sbi_printf("timer_mtimer_cold_init: mtimecmp_size = 0x%08lx\n", mt->mtimecmp_size);
+
/* Apply additional quirks */
if (quirks) {

4
ox-plic.dts
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@ -234,7 +234,9 @@
/*<&CPU0 0x3>, <&CPU0 0x7>,*/
/*<&onic_pool 0x3>, <&onic_pool 0x7>,*/
/*<&SERIAL 0x3>, <&SERIAL 0x7>*/
compatible = "riscv,clint0";
/* Allows using the "generic" platform in OpenSBI. */
compatible = "riscv,aclint-mtimer";
};
/* Guesswork: There must be a timer at 0x40170000 as it is