[PATCH] [MSP430] Fix relocation type for _bsssize being R_MSP430X_ABS16 when large memory model is used

[Jozef Lawrynowicz <jozef.l@somniumtech.com>]

For the msp430 target, trying to link a program with .bss larger than
64K causes a few different errors to be reported.

> /usr/local/bin/../lib/gcc/msp430-elf/6.3.1/../../../../msp430-elf/bin/ld: stone-msp430 section `.bss' will not fit in region `RAM'
> /usr/local/bin/../lib/gcc/msp430-elf/6.3.1/../../../../msp430-elf/bin/ld: region `RAM' overflowed by 65906 bytes
> /usr/local/bin/../lib/gcc/msp430-elf/6.3.1/../../../../msp430-elf/lib/large/libcrt.a(crt_bss.o): In function `.Loc.75.1':
> [...]/msp430-elf/large/libgloss/msp430/../../../../../libgloss/msp430/crt0.S:73:(.crt_0100init_bss+0x8): relocation truncated to fit: R_MSP430X_ABS16 against symbol `__bsssize' defined in *ABS* section in stone-msp430

Even though BSS shouldn't be larger than 64K, the relocation trunated
to fit error still looks like a bug.
The patch below changes one of the instructions in
libgloss/msp430/crt0.S from mov.w to mov_, so that the
R_MSP430X_ABS20_A relocation type is used instead of the
R_MSP430X_ABS16 for the _bsssize variable when the large memory model
is used. I also fixed a typo in a comment.
With the patch applied, linking the program with large bss now reports
only the following errors:

> /usr/local/bin/../lib/gcc/msp430-elf/6.3.1/../../../../msp430-elf/bin/ld: stone-msp430 section `.bss' will not fit in region `RAM'
> /usr/local/bin/../lib/gcc/msp430-elf/6.3.1/../../../../msp430-elf/bin/ld: region `RAM' overflowed by 65906 bytes

I don't have write access, so if this patch is satisfactory, I would
appreciate if someone could commit it for me.


From f79b243fafb2964e4d7b73edcf79dd7c7d087ac9 Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozef.l@somniumtech.com>
Date: Wed, 19 Apr 2017 11:47:13 +0000
Subject: [PATCH] Fix relocation type for _bsssize being R_MSP430X_ABS16 when
 large memory model is used

---
 libgloss/msp430/crt0.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libgloss/msp430/crt0.S b/libgloss/msp430/crt0.S
index 5c84e7c..f5ab8d3 100644
--- a/libgloss/msp430/crt0.S
+++ b/libgloss/msp430/crt0.S
@@ -72,9 +72,9 @@ START_CRT_FUNC 0100 init_bss

  mov_ #__bssstart, R12
  clr.w R13
- mov.w #__bsssize, R14
+ mov_ #__bsssize, R14
 #ifdef __MSP430X_LARGE__
- clr.w R15 ; We assume that __bsssize is never > 64M
+ clr.w R15 ; We assume that __bsssize is never > 64K
 #endif
  call_ #memset

-- 
1.8.3.1