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''SysRq debugger'' can help you to obtain some information from oops-ed kernel. This feature is available since 026test017 kernel.

''SysRq debugger'' can do one of the following:

# Dump memory at specified address

# Resolve symbol address by its name

To enter debug mode press ''SysRq-g''.

After this the following commands will be available:

# ''SysRq-q'' - quit debugger

After entering ''-d'', ''-w'' or ''-r'' state you must enter address to work with (and the value you want to write if you do). Simply do this by pressing according keys while holding ''Alt-StsRq''.

If you need to enter the upper case letter or the underbar (<code>_</code>) while typing a symbol name then you need to press and release ''shift'' and then the letter or minus (<code>-</code>).

At the end press ''enter''.

There is a <code>/proc/sysrq-trigger</code> entry which triggers sysrq events.

You may write a string to it to trigger commands one by one.

There is one note: the string must end with the <code>\r</code> character.

Here are some examples of how to use debugger

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# echo -n -e 'gd0xc0000000\rq' > /proc/sysrq-trigger

will dump memory region of 512 bytes

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# echo -n -e 'gxq' > /proc/sysrq-trigger

will dump the next 512 bytes of memory

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# echo -n -e 'gw0xc0000000-0x12345678\rq' > /proc/sysrq-trigger

will write ''0x12345678'' at ''0xc0000000''

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# echo -n -e 'grschedule\rq' > /proc/sysrq-trigger

will print you an address ''schedule()'' function starts from

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# echo -n -e 'gxq' > /proc/sysrq-trigger

will dump first 512 bytes of it

Note <i>''-n''</i> and <i>''-e''</i> keys to ''echo'' command.

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