That's what my first attempt tried to do, but it didn't seem to work.

I reduced mem_size (I think) inside the bd_info struct by 16K.

Just curious if there was a more properly intended way of going about it...

- Michael

Frank wrote:

--- "Michael R. Hines" mhines@google.com wrote:

...

I'd like to use the logbuffer functionality in u-boot...

After #define'ing CONFIG_LOGBUFFER, I can successfully see our data getting printed to the reserved 16K region in dram. However, we want to grab that data back out after linux has booted.

During the various initializations that linux does on boot, (somewhere before init is actually run, I believe), the data in the 16K buffer at the end of dram gets over-written by somebody inside linux, and is lost.

I found a thread somewhere on the net where Wolfgang mentioned that linux needed a patch to be told not to intrude on those logbuffer pages, but nothing more than that.

Is there a proper way to handle this?

Thanks,

• Michael R. Hines

I've never used the log buffer before, but I would think you could just tell the kernel you have less memory then is physically there. That way the kernel wouldn't touch the area used by the log buffer...

---

Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

That's exactly what I needed. Thank. Instead, however I reduced it by exactly 16 KB, the size of the logbuffer.

Frank wrote:

--- "Michael R. Hines" mhines@google.com wrote:

...

That's what my first attempt tried to do, but it didn't seem to work.

I reduced mem_size (I think) inside the bd_info struct by 16K.

Just curious if there was a more properly intended way of going about it...

• Michael

Frank wrote:

...

--- "Michael R. Hines" mhines@google.com wrote:

...

I'd like to use the logbuffer functionality in u-boot...

After #define'ing CONFIG_LOGBUFFER, I can successfully see our data getting printed to the reserved 16K region in dram. However, we want to grab that data back out after linux has booted.

During the various initializations that linux does on boot, (somewhere before init is actually run, I believe), the

data

...

...

in the 16K buffer at the end of dram gets over-written by somebody inside linux, and is lost.

I found a thread somewhere on the net where Wolfgang mentioned that linux needed a patch to be told not to intrude on those logbuffer pages, but nothing more than that.

Is there a proper way to handle this?

Thanks,

• Michael R. Hines

I've never used the log buffer before, but I would think you could just tell the kernel you have less memory then is physically there. That way the kernel wouldn't touch the

area

...

used by the log buffer...

Try reducing it on the kernel cmdline (mem=xxM) by 1Meg increments.

---

Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com