* Re: lager - non-booting latest horms' devel branch
2014-01-09 11:45 lager - non-booting latest horms' devel branch Ben Dooks
@ 2014-01-09 12:21 ` Geert Uytterhoeven
2014-01-09 12:30 ` Ben Dooks
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Geert Uytterhoeven @ 2014-01-09 12:21 UTC (permalink / raw)
To: linux-sh
Hi Ben,
On Thu, Jan 9, 2014 at 12:45 PM, Ben Dooks <ben.dooks@codethink.co.uk> wrote:
> I am using the devel branch from Simon Horms' git tree, SHA1
> 3da593ea7d797d9f59bd6ed1ee629fab681d7a23 and not seeing a
> boot when using the multi arch defconfig and device-tree.
>
> The board does not produce any console output so I am not
> sure what is going on. Has anyone else had issues with using
> the fdt-only boot?
I'm using Koelsch (not Lager), but usually the non-reference version as I
need Ethernet for NFS root.
The DT-version does boot for me until mounting root.
Are you using an initramfs? I noticed the kernel crashes early when using
a non-trivial initramfs:
Error: unrecognized/unsupported machine ID (r1 = 0x41915083).
Available machine support:
ID (hex) NAME
ffffffff Generic R8A7791 (Flattened Device Tree)
ffffffff koelsch
Please check your kernel config and/or bootloader.
Apparently the device tree gets overwritten in memory. I tried loading the
DTB at a different address, but that didn't help. I didn't have more time
to investigate, though.
FYI, I'm using the following patch to capture early kernel messages in RAM.
After a reset, look up the addres of big_buffer[] in System.map, and
inspect it from U-Boot to retrieve the messages (translate from 0xc0000000
to 0x40000000).
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index be7c86bae576..609bccc002ca 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -46,6 +46,7 @@
#include <linux/irq_work.h>
#include <linux/utsname.h>
+#include <asm/cacheflush.h>
#include <asm/uaccess.h>
#define CREATE_TRACE_POINTS
@@ -1488,6 +1489,9 @@ static size_t cont_print_text(char *text, size_t size)
return textlen;
}
+static char big_buffer[256*1024];
+static size_t big_buffer_index;
+
asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
@@ -1546,6 +1550,16 @@ asmlinkage int vprintk_emit(int facility, int level,
* prefix which might be passed-in as a parameter.
*/
text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
+if (big_buffer_index + text_len < sizeof(big_buffer)) {
+ memcpy(&big_buffer[big_buffer_index], text, text_len + 1);
+ big_buffer_index += text_len;
+} else if (big_buffer_index < sizeof(big_buffer)) {
+ memset(&big_buffer[big_buffer_index], '*',
+ sizeof(big_buffer) - big_buffer_index);
+ big_buffer[sizeof(big_buffer) - 1] = 0;
+ big_buffer_index = sizeof(big_buffer);
+}
+flush_cache_all();
/* mark and strip a trailing newline */
if (text_len && text[text_len-1] = '\n') {
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: lager - non-booting latest horms' devel branch
2014-01-09 11:45 lager - non-booting latest horms' devel branch Ben Dooks
2014-01-09 12:21 ` Geert Uytterhoeven
@ 2014-01-09 12:30 ` Ben Dooks
2014-01-09 14:42 ` Ben Dooks
2014-01-09 16:01 ` Ben Dooks
3 siblings, 0 replies; 5+ messages in thread
From: Ben Dooks @ 2014-01-09 12:30 UTC (permalink / raw)
To: linux-sh
On 09/01/14 12:21, Geert Uytterhoeven wrote:
> Hi Ben,
>
> On Thu, Jan 9, 2014 at 12:45 PM, Ben Dooks <ben.dooks@codethink.co.uk> wrote:
>> I am using the devel branch from Simon Horms' git tree, SHA1
>> 3da593ea7d797d9f59bd6ed1ee629fab681d7a23 and not seeing a
>> boot when using the multi arch defconfig and device-tree.
>>
>> The board does not produce any console output so I am not
>> sure what is going on. Has anyone else had issues with using
>> the fdt-only boot?
>
> I'm using Koelsch (not Lager), but usually the non-reference version as I
> need Ethernet for NFS root.
> The DT-version does boot for me until mounting root.
>
> Are you using an initramfs? I noticed the kernel crashes early when using
> a non-trivial initramfs:
No, we're just tftping and then nfs-root.
> Error: unrecognized/unsupported machine ID (r1 = 0x41915083).
>
> Available machine support:
>
> ID (hex) NAME
> ffffffff Generic R8A7791 (Flattened Device Tree)
> ffffffff koelsch
>
> Please check your kernel config and/or bootloader.
>
> Apparently the device tree gets overwritten in memory. I tried loading the
> DTB at a different address, but that didn't help. I didn't have more time
> to investigate, though.
I've managed to get it to boot with another boot method, however that
has other limitations...
>
> FYI, I'm using the following patch to capture early kernel messages in RAM.
> After a reset, look up the addres of big_buffer[] in System.map, and
> inspect it from U-Boot to retrieve the messages (translate from 0xc0000000
> to 0x40000000).
Ta, that's a useful thing to have
i am considering it may be a dtc compiler bug or some other issue with
the device-tree.
--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius
^ permalink raw reply [flat|nested] 5+ messages in thread