diff options
Diffstat (limited to 'backends/plugins/shorts-segment-manager.h')
| -rw-r--r-- | backends/plugins/shorts-segment-manager.h | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/backends/plugins/shorts-segment-manager.h b/backends/plugins/shorts-segment-manager.h index caefc7da8c..2710a7b9ff 100644 --- a/backends/plugins/shorts-segment-manager.h +++ b/backends/plugins/shorts-segment-manager.h @@ -35,10 +35,19 @@ #define ShortsMan ShortSegmentManager::instance() /** - * Manages the segments of small data put in the gp-relative area for MIPS processors, - * and lets these segments be handled differently in the ELF loader. + * ShortSegmentManager + * + * Since MIPS is limited to 32 bits per instruction, loading data that's further away than 16 bits + * takes several instructions. Thus, small global data (which is likely to be accessed a lot from + * multiple locations) is often put into a GP-relative area (GP standing for the global pointer register) + * in MIPS processors. This class manages these segments of small global data, and is used by the + * member functions of MIPSDLObject, which query in information from this manager in order to deal with + * this segment during the loading/unloading of plugins. + * * Since there's no true dynamic linker to change the GP register between plugins and the main engine, - * custom linker scripts ensure the GP-area is in the same place for both. + * custom ld linker scripts for both the main executable and the plugins ensure the GP-area is in the + * same place for both. The ShortSegmentManager accesses this place via the symbols __plugin_hole_start + * and __plugin_hole_end, which are defined in those custom ld linker scripts. */ class ShortSegmentManager : public Common::Singleton<ShortSegmentManager> { private: |