On Mon, Oct 10, 2022 at 06:18:08PM +0200, Pali Rohár wrote:
On Monday 10 October 2022 09:54:02 Tom Rini wrote:
On Sun, Oct 09, 2022 at 09:37:13PM +0200, Pali Rohár wrote:
For some unknown reason GNU assembler version 2.31.1 (arm-linux-gnueabi-as from Debian Buster) cannot compile following code from located in file board/nokia/rx51/lowlevel_init.S:
kernoffs: .word KERNEL_OFFSET - (. - CONFIG_SYS_TEXT_BASE)
when CONFIG_SYS_TEXT_BASE is set to 0x80008000. It throws strange compile error which is even without line number:
AS board/nokia/rx51/lowlevel_init.o{standard input}: Assembler messages: {standard input}: Error: attempt to get value of unresolved symbol `L0' make[2]: *** [scripts/Makefile.build:293: board/nokia/rx51/lowlevel_init.o] Error 1
I have no idea about this error and my experiments showed that ARM GNU assembler is happy with negation of that number. So changing code to:
kernoffs: .word . - CONFIG_SYS_TEXT_BASE - KERNEL_OFFSET
and then replacing mathematical addition by substraction of "kernoffs" value (so calculation of address does not change) compiles assembler file without any error now.
There should be not any functional change.
Signed-off-by: Pali Rohár pali@kernel.org
Btw, is somebody understanding that compile error message? Is there (or was there) some real issue in the code, so assembler refuse to compile it? Or have I triggered bug in GNU assembler?
I would suggest filing a bug with upstream GNU assembler and seeing what they say.
And it is really a bug? Is not that issue in current code?
I think filing an issue is the best way to find out if we were relying on something undocumented that worked or if it's a regression in the tooling.