ARC: Adjustments for gcc 4.8

* DWARF unwinder related
  + Force DWARF2 compliant .debug_frame (gcc 4.8 defaults to DWARF4
    which kernel unwinder can't grok).
  + Discard the additional .eh_frame generated
  + Discard the dwarf4 debug info generated by -gdwarf-2 for normal
    no debug case

* 4.8 already uses arc600 multilibs for -mno-mpy

* switch to using uclibc compiler (to get -mmedium-calls and -mno-sdata)
  and also since buildroot can only use 1 toolchain

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

1 files changed, 16 insertions, 8 deletions

diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index d3c92f52d444..2555f5886af6 100644
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -125,6 +125,11 @@ SECTIONS
                 *(.debug_frame)
                 __end_unwind = .;
         }
+        /*
+         * gcc 4.8 generates this for -fasynchonous-unwind-tables,
+         * while we still use the .debug_frame based unwinder
+         */
+        /DISCARD/ : {   *(.eh_frame) }
 #else
         /DISCARD/ : {   *(.debug_frame) }
 #endif
@@ -142,15 +147,18 @@ SECTIONS
                 *(.arcextmap.*)
         }
 
+#ifndef CONFIG_DEBUG_INFO
         /* open-coded because we need .debug_frame seperately for unwinding */
-        .debug_aranges 0 : { *(.debug_aranges) }
-        .debug_pubnames 0 : { *(.debug_pubnames) }
-        .debug_info 0 : { *(.debug_info) }
-        .debug_abbrev 0 : { *(.debug_abbrev) }
-        .debug_line 0 : { *(.debug_line) }
-        .debug_str 0 : { *(.debug_str) }
-        .debug_loc 0 : { *(.debug_loc) }
-        .debug_macinfo 0 : { *(.debug_macinfo) }
+        /DISCARD/ : { *(.debug_aranges) }
+        /DISCARD/ : { *(.debug_pubnames) }
+        /DISCARD/ : { *(.debug_info) }
+        /DISCARD/ : { *(.debug_abbrev) }
+        /DISCARD/ : { *(.debug_line) }
+        /DISCARD/ : { *(.debug_str) }
+        /DISCARD/ : { *(.debug_loc) }
+        /DISCARD/ : { *(.debug_macinfo) }
+        /DISCARD/ : { *(.debug_ranges) }
+#endif
 
 #ifdef CONFIG_ARC_HAS_DCCM
         . = CONFIG_ARC_DCCM_BASE;