Re: [avr-libc-dev] 2.0.0 and XMega32E5 eeprom troubles...

[Scott Price]

On 02/10/2016 02:13 AM, Sivanupandi, Pitchumani wrote:
> > -----Original Message-----
> > From: address@hidden [mailto:avr-
> > address@hidden On Behalf Of Scott Price
> > Sent: 10 February 2016 00:54
> > To: address@hidden
> > Subject: [avr-libc-dev] 2.0.0 and XMega32E5 eeprom troubles...
> >
> >
> > I am not able to get any of the eeprom_write_* or eeprom_update_* functions
> > working on an XMega32E5.  There are no compile errors or warnings, the
> > functions just don't do anything.  The eeprom read functions that I am using
> > all work fine.
> >
> > I had previously been using a version of avr-libc that I lifted from
> > AVRStudio 6.2 to get support for the E5.  The eeprom functions worked well
> > on that version.
> >
> > I compiled it using gcc-4.9.3 on Ubuntu Trusty.
> >
> > Atmel's nvm functions work for me, but add a significant amount of code.
> >    I would rather use the ones from avr-libc, since I use them for all of my
> > other AVR projects.
> >
> > Looking through the code and the docs it seems like the functions should
> > work.
> >
> > I have done a number of experiments, including writing a fixed value to a
> > fixed location on boot then reading the eeprom out with avr-dude.
> > Nothing I have done has produced a successful write.
> >
> > What more information do you need, or what tests can I run to help debug
> > this?
>
> Hi Scott,
>
> If you are building avr-libc, could you try below patch?
> This is the related difference I could see from Atmel's avr-libc build.
>
> Regards,
> Pitchumani
>
> diff --git a/avr-libc/libc/misc/eewr_byte.S b/avr-libc/libc/misc/eewr_byte.S
> index 98008c2..30b1595 100644
> --- a/avr-libc/libc/misc/eewr_byte.S
> +++ b/avr-libc/libc/misc/eewr_byte.S
> @@ -61,6 +61,12 @@ ENTRY        eeprom_write_r18
>   #  define NVM_CMD_ERASE_EEPROM_BUFFER_gc       0x36
>   # endif
>
> +#if    ! defined (NVM_EEMAPEN_bm)
> +  ; Saving X register because it might contain source address of block
> +    push XL
> +    push XH
> +#endif
> +
>     ; Prepare base address of NVM.
>          ldi     ZL, lo8(NVM_BASE)
>          ldi     ZH, hi8(NVM_BASE)
> @@ -136,6 +142,12 @@ ENTRY      eeprom_write_r18
>     ; Increment address.
>          adiw    addr_lo, 1
>
> +#if    ! defined (NVM_EEMAPEN_bm)
> +  ; Restoring X register
> +    pop XH
> +    pop XL
> +#endif
> +
>          ret
>
>   #else          /* ---------------------------------------------------- */
>
>
> _______________________________________________
> AVR-libc-dev mailing list
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That gives me the same result. No warnings or errors, it just does 
nothing. It is like it is not getting called or compiled in. The map 
file from gcc says it is taking up 0x46 bytes of memory in 
.text.avr-libc, so it is getting compiled in.

After hacking around some, I found the patch below makes it work for me. 
Granted, it is not a good solution, as it probably breaks things for all 
other XMegas. ;) I am only using the E5 currently.

Thanks!

Scott =)


--- eewr_byte.S.orig 2016-02-10 08:22:16.373013183 -0600
+++ eewr_byte.S 2016-02-10 08:28:46.638860509 -0600
@@ -116,7 +116,7 @@
std Z + NVM_ADDR0 - NVM_BASE, addr_lo
std Z + NVM_ADDR1 - NVM_BASE, addr_hi
std Z + NVM_ADDR2 - NVM_BASE, __zero_reg__
-#if defined (NVM_EEMAPEN_bm)
+#if !defined (NVM_EEMAPEN_bm)
std Z + NVM_DATA0 - NVM_BASE, r18
#else
movw XL, addr_lo




--
Scott L. Price, P.E.
Electrical Engineering/IT Manager
Hunt Utilities Group LLC                     http://www.hugllc.com
Pine River, MN                               (218) 587-5001
MN Electrical Licenses:  Master #AM08525  Power Limited #PL11071