From fba2ae7b2c43d3e706849c8098930683cbd0e322 Mon Sep 17 00:00:00 2001
From: "Deng, Yimin (NSB - CN/Shanghai)" <yimin.deng@nokia-sbell.com>
Date: Wed, 18 Apr 2018 03:12:45 +0000
Subject: [PATCH] mipsN32: A modification suggestion to support mips N32

---
 include/libunwind-mips.h        | 2 +-
 include/tdep-mips/libunwind_i.h | 8 ++++++++
 src/mips/Gcreate_addr_space.c   | 8 ++++++++
 src/mips/Gregs.c                | 3 ++-
 4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/include/libunwind-mips.h b/include/libunwind-mips.h
index 97c95e24..ced34b20 100644
--- a/include/libunwind-mips.h
+++ b/include/libunwind-mips.h
@@ -98,7 +98,7 @@ typedef enum
     UNW_MIPS_R30,
     UNW_MIPS_R31,
 
-    UNW_MIPS_PC = 34,
+    UNW_MIPS_PC = 64,
 
     /* FIXME: Other registers!  */
 
diff --git a/include/tdep-mips/libunwind_i.h b/include/tdep-mips/libunwind_i.h
index 3fe40c0c..0c0fd3cf 100644
--- a/include/tdep-mips/libunwind_i.h
+++ b/include/tdep-mips/libunwind_i.h
@@ -247,6 +247,14 @@ dwarf_get (struct dwarf_cursor *c, dwarf_loc_t loc, unw_word_t *val)
                                      0, c->as_arg);
   else if (c->as->abi == UNW_MIPS_ABI_O32)
     return read_s32 (c, DWARF_GET_LOC (loc), val);
+  else if (c->as->abi == UNW_MIPS_ABI_N32) {
+    if (tdep_big_endian(c->as))
+      return (*c->as->acc.access_mem) (c->as, DWARF_GET_LOC (loc) + 4, val,
+                                       0, c->as_arg);
+    else
+      return (*c->as->acc.access_mem) (c->as, DWARF_GET_LOC (loc), val,
+                                       0, c->as_arg);
+  }
   else
     return (*c->as->acc.access_mem) (c->as, DWARF_GET_LOC (loc), val,
                                      0, c->as_arg);
diff --git a/src/mips/Gcreate_addr_space.c b/src/mips/Gcreate_addr_space.c
index 493d03db..c2408b95 100644
--- a/src/mips/Gcreate_addr_space.c
+++ b/src/mips/Gcreate_addr_space.c
@@ -58,7 +58,15 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
     as->big_endian = (byte_order == __BIG_ENDIAN);
 
   /* FIXME!  There is no way to specify the ABI.  */
+#if _MIPS_SIM == _ABIO32
   as->abi = UNW_MIPS_ABI_O32;
+#elif _MIPS_SIM == _ABIN32
+  as->abi = UNW_MIPS_ABI_N32;
+#elif _MIPS_SIM == _ABI64
+  as->abi = UNW_MIPS_ABI_N64;
+#else
+# error Unsupported ABI
+#endif
   as->addr_size = 4;
 
   return as;
diff --git a/src/mips/Gregs.c b/src/mips/Gregs.c
index 95194022..e967324d 100644
--- a/src/mips/Gregs.c
+++ b/src/mips/Gregs.c
@@ -63,7 +63,7 @@ tdep_access_reg (struct cursor *c, unw_regnum_t reg, unw_word_t *valp,
     case UNW_MIPS_R26:
     case UNW_MIPS_R27:
     case UNW_MIPS_R28:
-    case UNW_MIPS_R29:
+
     case UNW_MIPS_R30:
     case UNW_MIPS_R31:
       loc = c->dwarf.loc[reg - UNW_MIPS_R0];
@@ -75,6 +75,7 @@ tdep_access_reg (struct cursor *c, unw_regnum_t reg, unw_word_t *valp,
       loc = c->dwarf.loc[reg];
       break;
 
+    case UNW_MIPS_R29:
     case UNW_MIPS_CFA:
       if (write)
         return -UNW_EREADONLYREG;