xtensa: intel_s1000: update to GDB 8.3.1

dcpleung · galak · commit 9c2435319e35 · 2020-03-11T07:08:16.000-06:00
The intel_s1000 SoC (and the corresponding intel_s1000_crb board) uses Tensilica's own xt-ocd for debugging, which works well with Tensilica's own xt-gdb but based on an older version. To make upstream GDB 8.3 work with xt-ocd, the following modifications are needed: () Introduce an option to use the remote target register number instead of the sequential number as defined in xtensa-config.c. This affects read/write of registers as xt-ocd maps registers to their target number. QEMU, on the other hand, uses the sequential number. Therefore only turns on this option when building GDB for intel_s1000. () Registers that cannot be retrieved are marked unavailable instead of erroring out. There are priviledged registers which can only be retrieved with custom protocol used by xt-gdb. Upstream GDB does not support this. So instead of error out and stopping register retrieval, simply mark those registers as unavailable and continue reading remaining registers. () Add an option to not use 'g' packet. When GDB sends a 'g' packet to retrieve a group of registers, xt-ocd does not produce responses expected by upstream GDB, and GDB simply goes into an infinite loop hoping a correct response would eventually come. So this option is introduced to mark all as not in 'g' packet so GDB would use 'p/P' packets to read/write registers. Fixes #188 Signed-off-by: Daniel Leung <daniel.leung@intel.com>
diff --git a/configs/xtensa_intel_s1000.config b/configs/xtensa_intel_s1000.config
@@ -42,6 +42,7 @@ CT_CC_GCC_EXTRA_CONFIG_ARRAY="--with-gnu-ld --with-gnu-as --enable-initfini-arra
 CT_CC_LANG_CXX=y
 CT_CC_GCC_LIBSTDCXX_NANO=y
 CT_DEBUG_GDB=y
-CT_GDB_V_7_6=y
+CT_GDB_V_8_3=y
+CT_GDB_CROSS_EXTRA_CONFIG_ARRAY="--enable-xtensa-use-target-regnum --disable-xtensa-remote-g-packet"
 CT_ISL_V_0_18=y
 CT_LIBICONV_NEEDED=y
diff --git a/patches/gdb/8.3.1/0004-gdb-regenerate-configure-file.patch b/patches/gdb/8.3.1/0004-gdb-regenerate-configure-file.patch
@@ -0,0 +1,176 @@
+From db7169daa3c7159873510de97c3cfb271004cbd2 Mon Sep 17 00:00:00 2001
+From: Daniel Leung <danielcp@gmail.com>
+Date: Fri, 6 Mar 2020 11:06:32 -0800
+Subject: [PATCH 4/8] gdb: regenerate configure file
+
+configure is out-of-sync...
+
+Signed-off-by: Daniel Leung <danielcp@gmail.com>
+---
+ gdb/configure           | 14 +++++++++++++-
+ gdb/gdbserver/configure | 14 +++++++++++++-
+ gdb/testsuite/configure | 14 +++++++++++++-
+ 3 files changed, 39 insertions(+), 3 deletions(-)
+
+diff --git a/gdb/configure b/gdb/configure
+index 866564fbe6..352a56c6a2 100755
+--- a/gdb/configure
++++ b/gdb/configure
+@@ -825,6 +825,7 @@ infodir
+ docdir
+ oldincludedir
+ includedir
++runstatedir
+ localstatedir
+ sharedstatedir
+ sysconfdir
+@@ -958,6 +959,7 @@ datadir='${datarootdir}'
+ sysconfdir='${prefix}/etc'
+ sharedstatedir='${prefix}/com'
+ localstatedir='${prefix}/var'
++runstatedir='${localstatedir}/run'
+ includedir='${prefix}/include'
+ oldincludedir='/usr/include'
+ docdir='${datarootdir}/doc/${PACKAGE}'
+@@ -1210,6 +1212,15 @@ do
+   | -silent | --silent | --silen | --sile | --sil)
+     silent=yes ;;
+ 
++  -runstatedir | --runstatedir | --runstatedi | --runstated \
++  | --runstate | --runstat | --runsta | --runst | --runs \
++  | --run | --ru | --r)
++    ac_prev=runstatedir ;;
++  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
++  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
++  | --run=* | --ru=* | --r=*)
++    runstatedir=$ac_optarg ;;
++
+   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
+     ac_prev=sbindir ;;
+   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
+@@ -1347,7 +1358,7 @@ fi
+ for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
+ 		datadir sysconfdir sharedstatedir localstatedir includedir \
+ 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
+-		libdir localedir mandir
++		libdir localedir mandir runstatedir
+ do
+   eval ac_val=\$$ac_var
+   # Remove trailing slashes.
+@@ -1500,6 +1511,7 @@ Fine tuning of the installation directories:
+   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
+   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
+   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
++  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
+   --libdir=DIR            object code libraries [EPREFIX/lib]
+   --includedir=DIR        C header files [PREFIX/include]
+   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
+diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
+index 1ddbd6b27e..1d298fa824 100755
+--- a/gdb/gdbserver/configure
++++ b/gdb/gdbserver/configure
+@@ -697,6 +697,7 @@ infodir
+ docdir
+ oldincludedir
+ includedir
++runstatedir
+ localstatedir
+ sharedstatedir
+ sysconfdir
+@@ -784,6 +785,7 @@ datadir='${datarootdir}'
+ sysconfdir='${prefix}/etc'
+ sharedstatedir='${prefix}/com'
+ localstatedir='${prefix}/var'
++runstatedir='${localstatedir}/run'
+ includedir='${prefix}/include'
+ oldincludedir='/usr/include'
+ docdir='${datarootdir}/doc/${PACKAGE}'
+@@ -1036,6 +1038,15 @@ do
+   | -silent | --silent | --silen | --sile | --sil)
+     silent=yes ;;
+ 
++  -runstatedir | --runstatedir | --runstatedi | --runstated \
++  | --runstate | --runstat | --runsta | --runst | --runs \
++  | --run | --ru | --r)
++    ac_prev=runstatedir ;;
++  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
++  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
++  | --run=* | --ru=* | --r=*)
++    runstatedir=$ac_optarg ;;
++
+   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
+     ac_prev=sbindir ;;
+   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
+@@ -1173,7 +1184,7 @@ fi
+ for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
+ 		datadir sysconfdir sharedstatedir localstatedir includedir \
+ 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
+-		libdir localedir mandir
++		libdir localedir mandir runstatedir
+ do
+   eval ac_val=\$$ac_var
+   # Remove trailing slashes.
+@@ -1326,6 +1337,7 @@ Fine tuning of the installation directories:
+   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
+   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
+   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
++  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
+   --libdir=DIR            object code libraries [EPREFIX/lib]
+   --includedir=DIR        C header files [PREFIX/include]
+   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
+diff --git a/gdb/testsuite/configure b/gdb/testsuite/configure
+index cc00f8dfa8..dae183eae9 100755
+--- a/gdb/testsuite/configure
++++ b/gdb/testsuite/configure
+@@ -671,6 +671,7 @@ infodir
+ docdir
+ oldincludedir
+ includedir
++runstatedir
+ localstatedir
+ sharedstatedir
+ sysconfdir
+@@ -743,6 +744,7 @@ datadir='${datarootdir}'
+ sysconfdir='${prefix}/etc'
+ sharedstatedir='${prefix}/com'
+ localstatedir='${prefix}/var'
++runstatedir='${localstatedir}/run'
+ includedir='${prefix}/include'
+ oldincludedir='/usr/include'
+ docdir='${datarootdir}/doc/${PACKAGE}'
+@@ -995,6 +997,15 @@ do
+   | -silent | --silent | --silen | --sile | --sil)
+     silent=yes ;;
+ 
++  -runstatedir | --runstatedir | --runstatedi | --runstated \
++  | --runstate | --runstat | --runsta | --runst | --runs \
++  | --run | --ru | --r)
++    ac_prev=runstatedir ;;
++  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
++  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
++  | --run=* | --ru=* | --r=*)
++    runstatedir=$ac_optarg ;;
++
+   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
+     ac_prev=sbindir ;;
+   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
+@@ -1132,7 +1143,7 @@ fi
+ for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
+ 		datadir sysconfdir sharedstatedir localstatedir includedir \
+ 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
+-		libdir localedir mandir
++		libdir localedir mandir runstatedir
+ do
+   eval ac_val=\$$ac_var
+   # Remove trailing slashes.
+@@ -1285,6 +1296,7 @@ Fine tuning of the installation directories:
+   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
+   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
+   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
++  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
+   --libdir=DIR            object code libraries [EPREFIX/lib]
+   --includedir=DIR        C header files [PREFIX/include]
+   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
+-- 
+2.24.1
+
diff --git a/patches/gdb/8.3.1/0005-gdb-xtensa-don-t-error-out-when-registers-cannot-be-.patch b/patches/gdb/8.3.1/0005-gdb-xtensa-don-t-error-out-when-registers-cannot-be-.patch
@@ -0,0 +1,46 @@
+From 88cfe105614a576580bc3f36ee1f0d91cd37b781 Mon Sep 17 00:00:00 2001
+From: Daniel Leung <danielcp@gmail.com>
+Date: Thu, 5 Mar 2020 17:20:25 -0800
+Subject: [PATCH 5/8] gdb: xtensa: don't error out when registers cannot be
+ read
+
+On Xtensa, some privileged registers cannot be read using 'p'
+packet. So keep these marked as unavailable so GDB can still
+fetch other registers instead of stopping at error.
+
+Signed-off-by: Daniel Leung <danielcp@gmail.com>
+---
+ gdb/remote.c | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+diff --git a/gdb/remote.c b/gdb/remote.c
+index 36136e3e3e..c8c5b32c74 100644
+--- a/gdb/remote.c
++++ b/gdb/remote.c
+@@ -7933,6 +7933,7 @@ remote_target::fetch_register_using_p (struct regcache *regcache,
+   char *buf, *p;
+   gdb_byte *regp = (gdb_byte *) alloca (register_size (gdbarch, reg->regnum));
+   int i;
++  enum bfd_architecture bfd_arch = gdbarch_bfd_arch_info (gdbarch)->arch;
+ 
+   if (packet_support (PACKET_p) == PACKET_DISABLE)
+     return 0;
+@@ -7956,6 +7957,15 @@ remote_target::fetch_register_using_p (struct regcache *regcache,
+     case PACKET_UNKNOWN:
+       return 0;
+     case PACKET_ERROR:
++      /* On Xtensa, some privileged registers cannot be read using 'p'
++         packet. So keep these marked as unavailable so GDB can still
++         fetch other registers instead of stopping at error.  */
++      if (bfd_arch == bfd_arch_xtensa)
++        {
++          regcache->raw_supply (reg->regnum, NULL);
++          return 1;
++        }
++
+       error (_("Could not fetch register \"%s\"; remote failure reply '%s'"),
+ 	     gdbarch_register_name (regcache->arch (), 
+ 				    reg->regnum), 
+-- 
+2.24.1
+
diff --git a/patches/gdb/8.3.1/0006-gdb-xtensa-use-remote-target-register-number.patch b/patches/gdb/8.3.1/0006-gdb-xtensa-use-remote-target-register-number.patch
@@ -0,0 +1,124 @@
+From 5665931ee51625c9a29a41d845011be67ded7e54 Mon Sep 17 00:00:00 2001
+From: Daniel Leung <danielcp@gmail.com>
+Date: Thu, 5 Mar 2020 14:00:07 -0800
+Subject: [PATCH 6/8] gdb: xtensa: use remote target register number...
+
+...instead of the sequential number defined in xtensa-config.c
+when retrieving registers from remote target, as the remote
+probe maps registers to their target numbers.
+
+Signed-off-by: Daniel Leung <danielcp@gmail.com>
+---
+ gdb/configure     | 20 ++++++++++++++++++++
+ gdb/configure.ac  | 14 ++++++++++++++
+ gdb/xtensa-tdep.c | 17 +++++++++++++++++
+ 3 files changed, 51 insertions(+)
+
+diff --git a/gdb/configure b/gdb/configure
+index 352a56c6a2..e873b109ca 100755
+--- a/gdb/configure
++++ b/gdb/configure
+@@ -900,6 +900,7 @@ enable_sim
+ enable_gdbserver
+ with_babeltrace
+ with_libbabeltrace_prefix
++enable_xtensa_use_target_regnum
+ enable_unit_tests
+ '
+       ac_precious_vars='build_alias
+@@ -1579,6 +1580,8 @@ Optional Features:
+   --enable-sim            link gdb with simulator
+   --enable-gdbserver      automatically build gdbserver (yes/no/auto, default
+                           is auto)
++  --enable-xtensa-use-target-regnum
++                          Use remote target register numbers (Xtensa target)
+   --enable-unit-tests     Enable the inclusion of unit tests when compiling
+                           GDB
+ 
+@@ -17822,6 +17825,23 @@ $as_echo "$as_me: WARNING: babeltrace is missing or unusable; GDB is unable to r
+   fi
+ fi
+ 
++# Xtensa to use target register number
++# Check whether --enable-xtensa-use-target-regnum was given.
++if test "${enable_xtensa_use_target_regnum+set}" = set; then :
++  enableval=$enable_xtensa_use_target_regnum; case $enableval in
++    yes | no)
++      enable_xtensa_use_target_regnum=$enableval ;;
++    *)
++      as_fn_error $? "bad value $enableval for --enable-xtensa-use-target-regnum" "$LINENO" 5 ;;
++  esac
++else
++  enable_xtensa_use_target_regnum=no
++fi
++
++if test x"$enable_xtensa_use_target_regnum" = xyes; then
++  CPPFLAGS="$CPPFLAGS -DXTENSA_USE_TGT_REGNUM"
++fi
++
+ # If nativefile (NAT_FILE) is not set in configure.nat, we link to an
+ # empty version.
+ 
+diff --git a/gdb/configure.ac b/gdb/configure.ac
+index 0805827adf..56b004448f 100644
+--- a/gdb/configure.ac
++++ b/gdb/configure.ac
+@@ -2260,6 +2260,20 @@ else
+   fi
+ fi
+ 
++# Xtensa to use target register number
++AC_ARG_ENABLE(xtensa-use-target-regnum,
++AS_HELP_STRING([--enable-xtensa-use-target-regnum], [Use remote target register numbers (Xtensa target)]),
++  [case $enableval in
++    yes | no)
++      enable_xtensa_use_target_regnum=$enableval ;;
++    *)
++      AC_MSG_ERROR([bad value $enableval for --enable-xtensa-use-target-regnum]) ;;
++  esac],
++  [enable_xtensa_use_target_regnum=no])
++if test x"$enable_xtensa_use_target_regnum" = xyes; then
++  CPPFLAGS="$CPPFLAGS -DXTENSA_USE_TGT_REGNUM"
++fi
++
+ # If nativefile (NAT_FILE) is not set in configure.nat, we link to an
+ # empty version.
+ 
+diff --git a/gdb/xtensa-tdep.c b/gdb/xtensa-tdep.c
+index fcec9961ee..48f1005e9e 100644
+--- a/gdb/xtensa-tdep.c
++++ b/gdb/xtensa-tdep.c
+@@ -3145,6 +3145,19 @@ xtensa_derive_tdep (struct gdbarch_tdep *tdep)
+   tdep->max_register_virtual_size = max_size;
+ }
+ 
++#ifdef XTENSA_USE_TGT_REGNUM
++int
++xtensa_remote_register_number (struct gdbarch *gdbarch, int regnum)
++{
++  /* Return the name stored in the register map.  */
++  if (regnum >= 0 && regnum < gdbarch_num_cooked_regs (gdbarch))
++    return gdbarch_tdep (gdbarch)->regmap[regnum].target_number;
++
++  internal_error (__FILE__, __LINE__, _("invalid register %d"), regnum);
++  return regnum;
++}
++#endif
++
+ /* Module "constructor" function.  */
+ 
+ extern struct gdbarch_tdep xtensa_tdep;
+@@ -3193,6 +3206,10 @@ xtensa_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
+   set_gdbarch_register_name (gdbarch, xtensa_register_name);
+   set_gdbarch_register_type (gdbarch, xtensa_register_type);
+ 
++#ifdef XTENSA_USE_TGT_REGNUM
++  set_gdbarch_remote_register_number (gdbarch, xtensa_remote_register_number);
++#endif
++
+   /* To call functions from GDB using dummy frame.  */
+   set_gdbarch_push_dummy_call (gdbarch, xtensa_push_dummy_call);
+ 
+-- 
+2.24.1
+
diff --git a/patches/gdb/8.3.1/0007-gdb-arch-to-tell-whether-it-supports-g-packets.patch b/patches/gdb/8.3.1/0007-gdb-arch-to-tell-whether-it-supports-g-packets.patch
diff --git a/patches/gdb/8.3.1/0008-gdb-xtensa-does-not-support-g-packet.patch b/patches/gdb/8.3.1/0008-gdb-xtensa-does-not-support-g-packet.patch
