Georg-Johann Lay wrote: > This patch fixes several issues with RAMP registers: > > * On Devices with more than 64 KiB RAM, RAMPZ is used as high-byte of > RAM address. If RAMPZ is used to read flash, it must be reset to 0 > after the read so that RAM-read will operate correctly in the remainder. > There is no support for RAM > 64 Ki so RAMPZ = 0 is in order. > > * The ISR epilogue restored RAMP* registers in the wrong order. > > * As RAMPZ is used both in ELPM and LD/LDD on some xmega core, the right > condition to set RAMPZ prior to ELPM is "have ELPM", not "have RAMPZ". > > * Never read unintentionally from RAM because a flash address interpreted > as a RAM address might point to the I/O area. > > Ok for trunk and 4.7?
The following change in expand_prologue is wrong: - if (AVR_HAVE_RAMPZ + if (AVR_HAVE_RAMPD /* sic! */ similar in expand_epilogue. Ok without that change? > > Johann > > libgcc/ > PR target/52461 > * config/avr/lib1funcs.S (__do_copy_data): Clear RAMPZ after usage > if RAMPZ affects reading from RAM. > (__tablejump_elpm__): Ditto. > (.xload): Ditto. > (__movmemx_hi): Ditto. > (__do_global_ctors): Right condition for RAMPZ usage is "have ELPM". > (__do_global_dtors): Ditto. > (__xload_1, __xload_2, __xload_3, __xload_4): Ditto. And make weak. > (__movmemx_hi): Ditto. And fix RAM-loop label. > (__xload_1): Never read unintentionally from RAM. > > gcc/ > PR target/52461 > * gcc/config/avr/avr.c (expand_prologue): Depend save/restore of > RAMPZ on HAVE_RAMPD, not HAVE_RAMPZ. > (expand_epilogue): Ditto. And fix order of restoration to: > RAMPZ, RAMPY, RAMPX, RAMPD. > (avr_xload_libgcc_p): Always load __memx by lilbgcc call on > big-RAM devices. > (avr_out_lpm): Clear RAMPZ after usage if RAMPZ affects reading > from RAM. > (avr_out_xload): Never read unintentionally from RAM. > * config/avr/avr.md (xload_8): Adjust insn length.
