[PATCH] Nokia RX-51: Fix compilation with non-zero CONFIG_SYS_TEXT_BASE

["Pali Rohár" <pali@kernel.org>]

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?
---
 board/nokia/rx51/lowlevel_init.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/board/nokia/rx51/lowlevel_init.S b/board/nokia/rx51/lowlevel_init.S
index 1cf8f8d8b2f7..4b66e0a86140 100644
--- a/board/nokia/rx51/lowlevel_init.S
+++ b/board/nokia/rx51/lowlevel_init.S
@@ -7,7 +7,7 @@
 #include <config.h>
 
 kernoffs:		/* offset of kernel image from this address */
-	.word KERNEL_OFFSET - (. - CONFIG_SYS_TEXT_BASE)
+	.word . - CONFIG_SYS_TEXT_BASE - KERNEL_OFFSET
 
 kernaddr:		/* address of kernel after copying */
 	.word KERNEL_ADDRESS
@@ -49,7 +49,7 @@ save_boot_params:
 	/* r0 - start of kernel before */
 	adr	r0, kernoffs	/* r0 - current address of kernoffs section */
 	ldr	r1, kernoffs	/* r1 - offset of kernel image from kernoffs section */
-	add	r0, r0, r1
+	sub	r0, r0, r1
 
 	/* r3 - start of kernel after */
 	ldr	r3, kernaddr
-- 
2.20.1