On Mon, Mar 5, 2012 at 3:11 PM, Georg-Johann Lay <a...@gjlay.de> wrote:
> 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?
All commits to the 4.7 branch need explicit release manager approval. AVR
isn't primary/secondary so please do not change anything before is
released 4.7.0 for it.
> 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?
>> 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.
>> 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.