TMS320F280049: rts2800_fpu32_fast_supplement.lib: error: creating output section "FPUmathTables" without a SECTIONS specification

Hello Stephan,

StephanS said:

Where is this described?

Are there any linker command files that I can use as reference?

You can refer to the FPUfastRTS examples located in C2000Ware_5_00_00_00\libraries\math\FPUfastRTS\c28\examples. I tested this out, as long as you adjust the names of the memory sections appropriately in the command linker file, there are no errors.

StephanS said:

Does the 280049 have the FPUmathTables for logf() in ROM?

If yes: Where are they located?

I will forward this question to a boot ROM expert.

Best regards,

Omer Amir

Hi Omer Amir,

I have looked into the examples and it should be easy to migrate the memory section.

What I do not understand is where the ROMTABLES are defined.

I will wait for the boot ROM expert.

Best Regards,

Stephan

Any update on where the ROMTABLES are defined?

Still no boot ROM expert available???

Hi Stephan,

Sorry for the delay in my response.

So, a few questions:

1. can you try adding this to the CMD file under SECTIONS{}: "FPUmathTables : > FLASH_BANK0_SEC4" ? 

2. When I tried building without the CMD edit, I could still see the tables in the map file. Can you please check your map file?

3. The logf() is part of the math.h library and will be placed in your standard code space as per the linker CMD file. Are you looking for something other than this?

-Kedar

Hi Kedar,

let me try to explain:
We are using logf() in a time critical environment, so we do not want to use the default logf() from the rts2800_fpu32.lib which takes approx. 420 cycles.
This is the reason for using rts2800_fpu32_fast_supplement.lib that is supposed to take only 51 cycles.
We are building via dedicated makefile (gnu make), not via CCS.

Regarding your questions:
1.  When using rts2800_fpu32_fast_supplement.lib and adding FPUmathTables to the cmd file (FLASH), the project is built.
    We get something like
    .text      0    00082c20    00006c2a     
                  000880d0    00000038     rts2800_fpu32_fast_supplement.lib : log_f32.obj (.text)
    FPUmathTables
    *          0    0008becc    0000018e     
                      0008becc    000000d0     rts2800_fpu32_fast_supplement.lib : logtable_f32.obj (FPUmathTables)
                      0008bf9c    000000be                                       : exptable_f32.obj (FPUmathTables)
    So everything is fine, but it takes 72 instead of the expected 51 cycles.
2.  When using rts2800_fpu32_fast_supplement.lib without adding FPUmathTables to the cmd file, we get
    "error: creating output section "FPUmathTables" without a SECTIONS specification",
    no outfile is generated.
3.  When using the default logf() from the rts2800_fpu32.lib, we get something like
                  000854bc    0000012a     rts2800_fpu32.lib : e_logf.obj (.text)
    without errors, but with an execution time of 420 cycles.

For many other controllers, I find cmd files with

MEMORY
{
PAGE 0 :
     FPUTABLES      : origin = 0x3FD860, length = 0x0006A0
   ...
}

SECTIONS
{
         FPUmathTables     : load = FPUTABLES,     PAGE = 0
         ...
}

So my question was if the 28004x also has FPUTABLES in ROM and if so where.

Best regards,
Stephan

I found an example here:
\\\C2000Ware_5_00_00_00\libraries\math\FPUfastRTS\c28\examples\log_f32

Can you see if this works for you? This is from the C2KWare.

-Kedar

Hmm, I see cmd files for

f280013x
f280015x
f2838x
f28003x
f28002x

but none for f28004x....

This issue is still unresolved...

Hi Stephan.

I will check this with the internal teams. But to unblock your case, you just need to add the corresponding lines under MEMORY{} and SECTIONS{} in your selected CMD file and link the FPUfastRTS library in your linker options.

-Kedar

Hi Kedar,

that's what I already did, and it's working with FPUmathTables in Flash (taking more cycles than expected).

For the remaining question
"Does the 280049 have the FPUmathTables for logf() in ROM? If yes: Where are they located?",
I will wait for your internal teams check result.

Best regards,

Stephan

Hi Kedar,

do you finally have internal teams check results?

-Stephan