Having accidentally erased the calibration values from INFOA Flash.
It sounds simple enough, that for simple convenience I'd ideally
like to be able to restore the values I was careful enough to write
down (for the ONLY board I'll be using), as a conditional build
option.

However, there appears to be a linker segment clash, I can't figure
out how to avoid. It works links with predictable results, if I move
the array down 8-bytes. So I guess the problem is due to the
competeing CALIB definition in the standard IAR header files. Can
anybody suggest how I coud trick the compiler into generating the
desired build-image ?

#pragma constseg=INFOA
const unsigned int calib[] @0x10F8 {
0x8ED8, // CALDCO_16MHZ & CALBC1_16MHZ
0x8E68, // CALDCO_12MHZ & CALBC1_12MHZ
0x8D50, // CALDCO_8MHZ & CALBC1_8MHZ
0x869C // CALDCO_1MHZ & CALBC1_1MHZ
};
#pragma constsegault

Linker error[e24]: Segment DATA16_AC (seg part no 21, symbol "calib"
in module "ta_uart", address [10f8-10ff]) overlaps segment
DATA16_AN (seg part no 19, symbol "CALDCO_16MHZ" in
module "ta_uart", address [10f8-10f8])

Many thanks,

Colin, Start a New Thread

colin_garlick wrote:
> Having accidentally erased the calibration values from INFOA Flash.
> It sounds simple enough, that for simple convenience I'd ideally
> like to be able to restore the values I was careful enough to write
> down (for the ONLY board I'll be using), as a conditional build
> option.
>
> However, there appears to be a linker segment clash, I can't figure
> out how to avoid. It works links with predictable results, if I move
> the array down 8-bytes. So I guess the problem is due to the
> competeing CALIB definition in the standard IAR header files. Can
> anybody suggest how I coud trick the compiler into generating the
> desired build-image ?
>
> #pragma constseg=INFOA
> const unsigned int calib[] @0x10F8 > {
> 0x8ED8, // CALDCO_16MHZ & CALBC1_16MHZ
> 0x8E68, // CALDCO_12MHZ & CALBC1_12MHZ
> 0x8D50, // CALDCO_8MHZ & CALBC1_8MHZ
> 0x869C // CALDCO_1MHZ & CALBC1_1MHZ
> };
> #pragma constsegault
>
> Linker error[e24]: Segment DATA16_AC (seg part no 21, symbol "calib"
> in module "ta_uart", address [10f8-10ff]) overlaps segment
> DATA16_AN (seg part no 19, symbol "CALDCO_16MHZ" in
> module "ta_uart", address [10f8-10f8])

Hi Colin!

The linker will treat your array and the definition in the header file
as two distinct variables that are placed at the same location, hence
the linker error.

I would try to use only one definition throughout the application, since
you need the initial value you can't use the CALDCO_16MHZ symbol.

-- Anders Lindgren, IAR Systems

Ps. You don't need both #pragma constseg and the @0x10f8 notation. In
fact, the "constseg" pragma is provided for backward compatibility only,
in modern a IAR compiler you can write '@ 0x10f8' or '@ "INFOA"'.

--
Disclaimer: Opinions expressed in this posting are strictly my own and
not necessarily those of my employer. Start a New Thread

Most of the current F20xx chips have a silicon bug (called FLASH16).
If you try to erase/write to locked flash (i.e., INFOA at 0x10C0-
0x10FF), it will erase/write part of the main-Flash at 0xFC40-0xFC7F
instead of the INFOA at 0x10C0-0x10FF. Thus make sure that you enable
the Allow erase/write access to locked flash memory (under
Project => Options => FET Debugger).

If your religion allows you to use assembly code, you can use the
following code.

RSEG INFOA
ORG 0x38
DC16 0x8ED8
DC16 0x8E68
DC16 0x8D50
DC16 0x869C
END

I know. This is not ANSII stuff. But it is simple and it works.

--- In m..., Anders Lindgren
wrote:
>
> colin_garlick wrote:
> >
> >
> > Having accidentally erased the calibration values from INFOA
Flash.
> > It sounds simple enough, that for simple convenience I'd ideally
> > like to be able to restore the values I was careful enough to
write
> > down (for the ONLY board I'll be using), as a conditional build
> > option.
> >
> > However, there appears to be a linker segment clash, I can't
figure
> > out how to avoid. It works links with predictable results, if I
move
> > the array down 8-bytes. So I guess the problem is due to the
> > competeing CALIB definition in the standard IAR header files. Can
> > anybody suggest how I coud trick the compiler into generating the
> > desired build-image ?
> >
> > #pragma constseg=INFOA
> > const unsigned int calib[] @0x10F8 > > {
> > 0x8ED8, // CALDCO_16MHZ & CALBC1_16MHZ
> > 0x8E68, // CALDCO_12MHZ & CALBC1_12MHZ
> > 0x8D50, // CALDCO_8MHZ & CALBC1_8MHZ
> > 0x869C // CALDCO_1MHZ & CALBC1_1MHZ
> > };
> > #pragma constsegault
> >
> > Linker error[e24]: Segment DATA16_AC (seg part no 21,
symbol "calib"
> > in module "ta_uart", address [10f8-10ff]) overlaps segment
> > DATA16_AN (seg part no 19, symbol "CALDCO_16MHZ" in
> > module "ta_uart", address [10f8-10f8])
>
> Hi Colin!
>
> The linker will treat your array and the definition in the header
file
> as two distinct variables that are placed at the same location,
hence
> the linker error.
>
> I would try to use only one definition throughout the application,
since
> you need the initial value you can't use the CALDCO_16MHZ symbol.
>
> -- Anders Lindgren, IAR Systems
>
> Ps. You don't need both #pragma constseg and the @0x10f8 notation.
In
> fact, the "constseg" pragma is provided for backward compatibility
only,
> in modern a IAR compiler you can write '@ 0x10f8' or '@ "INFOA"'.
>
> --
> Disclaimer: Opinions expressed in this posting are strictly my own
and
> not necessarily those of my employer.
> Start a New Thread