Error when compiling Kernel

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Felix
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Posts: 2
Joined: Wed 2018-05-02 18:02

Error when compiling Kernel

Post by Felix » Fri 2018-12-28 0:22

Dear Forum,

when I try to compile the latest Kernel, i get the following error:

ERROR: vslink: section TransientAddKernelSymbolsAsm not mapped to transient_i

Is there a simple solution to this? Thank you very much!

Kind regards

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Panu
VLSI Staff
Posts: 2672
Joined: Tue 2010-06-22 13:43

Re: Error when compiling Kernel

Post by Panu » Sat 2018-12-29 10:59

Hi!

Supposing, that you have NOT modified the kernel yourself, the real simple solution is.... to compile it again and again until it is successful.

The long term solution is to increase the size of the transient_i segment by a few words in the memory map file.

Here's what is happening: The LCC compiler uses memory addresses as seeds for the register allocator. As memory addresses became randomized in some version of the Windows kernel, this lead to the situation where registers are allocated a little bit differently each time you compile. And occasionally, although rarely, this can increase or decrease the size of the executable by a few words.

Transient_i is a segment where stuff that is needed only during the VSOS bootup is loaded. So it's plcaed at the end of program memory. After the OS has booted, user programs can and will be loaded over this memory area, so we need to be sure that the linker doesn't accidentally put anything into this segment, that is not supposed to be there. That's why we set the size of the segment to be just about exactly the expected size of the sections that are directed to go there in the linker command file. And sometimes, especially with WIndows 10, this scheme backfires slightly and you get this error.

-Panu
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