openxiangshan / libcheckpoint

LibCheckpoint

LibCheckpoint is a restorer of "rvgcpt checkpoint" for restoring in-memory architectural state into registers.

Provides the following functions:

• restore checkpoint which using protobuf point to memory layout (max cores: 128)
• restore dual core "rvgcpt checkpoint" which using qemu generate (https://github.com/OpenXiangShan/qemu/tree/checkpoint) (Currently the most commonly used)
• limited M-mode checkpoint restore (it is best not to try to generate checkpoints on bare metal programs)
• output the in-memory architecture state (before recovery)
• block core N (using for debug)

How to

1. Init

pip install --upgrade protobuf grpcio-tools
git submodule update --init

2. Build for restore checkpoint that using protobuf and 'checkpoint' device (Not officially put into use, only passed testing)

make clean && make -j

3. Build for qemu dual core checkpoint that put serialize data at 0x80300000~0x80800000 (stable)

make clean && make USING_QEMU_DUAL_CORE_SYSTEM=1

4. Build restorer that can pause a core's operation (stable)

make STOP_CPU_N=n # n could be any hartid

5. Build restorer that can display serialize data from memory before unserialize to hardware (stable)

make DISPLAY_CPU_N=0 # n could be any hartid, one appropriate approach is to suspend one of the cores in a dual-core checkpoint and output the serialized data from the other core

6. Build for link next level bootloader (stable)

make GCPT_PAYLOAD_PATH=/path/to/bbl.bin # default: put next level bootloader at address 0x80100000
make GCPT_PAYLOAD_PATH=/path/to/bbl.bin GCPT_PAYLOAD_POSITION=0x???????? # point to link address

• The above options are not mutually exclusive and can be used in any combination

Reference

• protobuf (https://github.com/nanopb/nanopb)
• printf (https://github.com/mpaland/printf)
• gcpt_restore (https://github.com/OpenXiangShan/LibCheckpointAlpha)

FAQ:

• warning: build/gcpt has a LOAD segment with RWX permissions
  • this warning does not affect any normal use