topic Re: No linker error when exceeding m_text because of __DATA_ROM in S32 Design Studio

No linker error when exceeding m_text because of __DATA_ROM

tommy1231 — Tue, 10 Dec 2019 18:42:30 GMT

Using the default linker file for the S32k144 that the S32DS comes with, the linker fails to generate an error when the allowed size for the m_text is exceeded. Looking at the linker file it doesn't directly put the data ROM into m_text but rather creates some variables and uses those. This prevents the linker from generating an error when the assigned sized of m_text is exceeded.

In my case my linker for the m_text looks like this

m_text (RX) : ORIGIN = 0x00002404, LENGTH = 0x0000FBFC

I would expect that if anything stored in this section goes beyond 0x12000 the linker would generate an error.

If the .text section exceeds the size it triggers and error.

However these two sections also go into flash but do not trigger an error because they are not directly placed into m_text but rather use variables defined in the linker file (__DATA_ROM & __CODE_ROM)

.data : AT(__DATA_ROM)
.code : AT(__CODE_ROM)

How can I get the linker to properly trigger an error?

Re: No linker error when exceeding m_text because of __DATA_ROM

jiri_kral — Wed, 05 Feb 2020 11:26:39 GMT

Hi,

I'm not sure about your scenario. By default - when section size is exceeded linker error message is shown:

Can you share your project or .map file?

What's your size output from build console?

Jiri

Re: No linker error when exceeding m_text because of __DATA_ROM

tommy1231 — Wed, 05 Feb 2020 18:17:33 GMT

Hi Jiri,

If I shrink the size of m_text enough I do get the error like you said

However if I make the size big enough for m_text to fit but not big enough for these sections it doesn't give an error

.data : AT(__DATA_ROM)
.code : AT(__CODE_ROM)

Notice if you add the text size to the data size it is 0xACC8 which is larger than I allowed the space to be

From the map file it goes past the allowed space (0x2404 + 0xA000 = 0xC404)

*fill* 0x1fff0ce9 0x3
0x1fff0cec __data_end__ = .
0x0000cca4 __DATA_END = (__DATA_ROM + (__data_end__ - __data_start__))
0x0000cca4 __CODE_ROM = __DATA_END

The generated srecord also shows it going beyond.

S113CCC438BD2B685A1CF2D09847F0E700000240A4

Re: No linker error when exceeding m_text because of __DATA_ROM

raresvasile — Thu, 06 Feb 2020 12:19:13 GMT

Hi Tom,

Can you add the following line at the end of the linker script? (after line 208)

ASSERT(__CUSTOM_END >= (ORIGIN(m_text) + LENGTH(m_text)), "region m_text overflowed with code and rom data")

This should do the trick.

Best regards,

Rares

Re: No linker error when exceeding m_text because of __DATA_ROM

tommy1231 — Thu, 06 Feb 2020 17:07:40 GMT

Hi Rares,

It almost did the trick. The ASSERT happens when the condition is false so I had to flip the greater than to a less than

ASSERT(__CUSTOM_END < (ORIGIN(m_text) + LENGTH(m_text)), "region m_text overflowed with code and rom data")

I would suggest that this gets added to the default linker files that S32 DS generates as others might run into this as well.

Thank you,

Tom