Nios V, Max10, C++: region `reset' overflowed by 4 bytes

[andy25]

Everything was working fine, compiles ok, runs ok, then I added more code and suddenly:

[ 98%] Linking CXX executable app_free.elf
/quartus/V23.1-STD/riscfree/toolchain/riscv32-unknown-elf/bin/../lib/gcc/riscv32-unknown-elf/12.1.0/../../../../riscv32-unknown-elf/bin/ld: app_free.elf section `.entry' will not fit in region `reset'
/quartus/V23.1-STD/riscfree/toolchain/riscv32-unknown-elf/bin/../lib/gcc/riscv32-unknown-elf/12.1.0/../../../../riscv32-unknown-elf/bin/ld: region `reset' overflowed by 4 bytes
collect2: error: ld returned 1 exit status
make[3]: *** [CMakeFiles/app_free.elf.dir/build.make:115: app_free.elf] Error 1
make[2]: *** [CMakeFiles/Makefile2:104: CMakeFiles/app_free.elf.dir/all] Error 2
make[1]: *** [Makefile:91: all] Error 2

This is not the first time we have seen this error, but it magically comes and goes.

What goes into the .entry section?

Why is it overflowing by 4 bytes?

Why cant I just increase the reset region in bsp-editor?

Thanks for your time,

-Andy

[andy25 · Accepted solution]

I think I found an answer.  My Nios Reset was pointing to on-chip memory, with base 0xc000000.

.text was in external ddr3 at base 0x0, and __start was at 0x804.

Generating the linker map I see:

.entry          0x000000000c000000       0x24
 *(.entry)
 .entry         0x000000000c000000       0x24 freertos_bsp/libfreertos_bsp.a(crt0.S.obj)
                0x000000000c000000                __reset

Which tells me the only thing in the .entry section is __reset, and this is __reset in crt0.S:

    .section .entry, "xa"
    .align 5

    .globl __reset
    .type __reset, @function
__reset:
/*
 * Jump to the _start entry point in the .text section if reset code
 * is allowed or if optimizing for RTL simulation.
 */

    /* Jump to the _start entry point in the .text section. */
    tail _start

    .size __reset, . - __reset

I'm wondering if the "tail _start" instruction had to be encoded with extra bits because I'm jumping from 0xc000000 to 0x804?

When I switched my Nios reset to also point to external ddr3, then my C++ compiled ok.

Now my .entry is at 0x0, and _start is still 0x804. 

Does that seem like a reasonable explanation?

[EBERLAZARE_I_Intel]

Hi,

If you're using the OCRAM as reset vector, have you tried to increase the OCRAM size? Also, are you using the OCRAM II IP?

[andy25]

My OCRAM is 86K.  It did not say region reset couldnt fit into region OCRAM.  It said:

section `.entry' will not fit in region `reset'

The region reset is 32 bytes and fit inside OCRAM fine.

Its .entry that didnt fit into region reset.

Max10 does not have OCRAM II IP, so, no, I'm not using it.

-Andy

[EBERLAZARE_I_Intel]

Hi,

Yeah, I did got the same error previously.

But for your case is the Max 10, I need to check on that, my apologies for the late response, I will get back to you soon.

Thank you for your patience.

[EBERLAZARE_I_Intel]

Hi,

Ok I got the issue on my side too, so I was using the Nios V GSFI + XIP:

https://www.intel.com/content/www/us/en/docs/programmable/726952/23-4/software-design-flow-11011.html

The issue was with my BSP's .text, by default it was set to OCRAM, by right it should be set to the Nios V reset vector set in the Nios V IP(GSFI) in Platform Designer.

After changing from OCRAM to GSFI, now everything is OK too.

So things to check on the "region `reset' overflowed by 4 bytes":

1. Check your Nios V reset vector
2. BSP editor ".text" in "Linker Section Name" list need to be the same as your Nios V reset vector

[EBERLAZARE_I_Intel]

Hi,

Do you have further questions?

[andy25]

No, I guess not.

[EBERLAZARE_I_Intel]

Hi,

Thanks for the update.

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