[coreboot] Mysterious "is VARVERIFY32INIT but used from" problem while trying to improve SeaBIOS

[Mike Banon]

Friends, I need your help. While trying to improve SeaBIOS I got stuck
at this very strange problem - which does not appear when you do a
standalone build of SeaBIOS but it happens when you try building a
coreboot together with SeaBIOS. Steps to reproduce:

add this innocent looking function to the beginning of
./coreboot/payloads/external/SeaBIOS/seabios/src/fw/coreboot.c :

int // doesn't matter if static or not
testfunc(void) {
int *c = malloc_tmp(sizeof(int)); // doesn't matter if _tmp or _tmphigh
// free(c); // <--- commented out because doesn't affect the results
return 0;
}

and try calling it from "cbfs_copyfile" function of the same file:

static int cbfs_copyfile(struct romfile_s *file, void *dst, u32 maxlen) {
...
void *temp = malloc_tmphigh(size);
...
int ret = ulzma(dst, maxlen, temp, size);
testfunc(); // <--- added
...
}

Then I get this problem while building a coreboot with together SeaBIOS :
...
  Compiling whole program out/code32seg.o
  Compiling whole program out/ccode16.o
  Compiling to assembler out/src/asm-offsets.s
  Generating offset file out/asm-offsets.h
  Compiling (16bit) out/romlayout.o
  Building ld scripts

ERROR: .data.varinit.. is VARVERIFY32INIT but used from
['.text.runtime..', '.text.do_boot', '.text.malloc_tmp']
Makefile:162: recipe for target 'out/romlayout16.lds' failed
make[2]: *** [out/romlayout16.lds] Error 1
Makefile:80: recipe for target 'build' failed
make[1]: *** [build] Error 2
payloads/external/Makefile.inc:73: recipe for target
'payloads/external/SeaBIOS/seabios/out/bios.bin.elf' failed
make: *** [payloads/external/SeaBIOS/seabios/out/bios.bin.elf] Error 2

However, if I try adding this function to the end of
"coreboot_cbfs_init" function I don't get such an error:

void coreboot_cbfs_init(void) {
...
process_links_file();
testfunc(); // <--- works OK there
}

What is a difference between "cbfs_copyfile" and "coreboot_cbfs_init"
that affects this behaviour? And why it is OK to call "malloc_" from
inside the "cbfs_copyfile" function --- void *temp =
malloc_tmphigh(size); --- but we couldn't call there our testfunc()
which calls "malloc_" without running into this problem?

Best regards,
Mike Banon