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soc:2008:stefanha:notes:start [2008/05/20 00:38] stefanha |
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| ===== Notes ===== | ===== Notes ===== | ||
| - | * Linux [[kgdb|http://kgdb.linsyssoft.com/]] [[http://kgdb.cvs.sourceforge.net/kgdb/kgdb-2/eth.patch?revision=1.60&view=markup|over Ethernet]] using the [[http://www.selenic.com/netpoll/|Netpoll API]]. | + | * Linux [[http://kgdb.linsyssoft.com/|kgdb]] [[http://kgdb.cvs.sourceforge.net/kgdb/kgdb-2/eth.patch?revision=1.60&view=markup|over Ethernet]] using the [[http://www.selenic.com/netpoll/|Netpoll API]]. |
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| + | === QEMU memory dumps === | ||
| + | The QEMU monitor (''CTRL+ALT+2'') supports debug commands to inspect registers and memory. Unfortunately, QEMU only honors paged virtual memory. Since gPXE sets up a virtual memory segment with a non-zero base address, all virtual addresses need to be adjusted before using them to inspect memory in QEMU. | ||
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| + | The virtual memory offset is available inside gPXE as ''virt_offset'' (see ''arch/i386/transitions/librm.S''). It can be printed out by placing a ''printf'' call in ''core/main.c''. | ||
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| + | When dumping memory, remember to add the value of ''virt_offset'' to any virtual memory addresses. QEMU is effectively using physical memory only. | ||
