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Re: [PATCH] CRIS downgrade from GDB_MULTI_ARCH 3 to 1
- From: Orjan Friberg <orjan dot friberg at axis dot com>
- To: Andrew Cagney <ac131313 at cygnus dot com>
- Cc: gdb-patches at sources dot redhat dot com
- Date: Fri, 21 Dec 2001 10:56:19 +0100
- Subject: Re: [PATCH] CRIS downgrade from GDB_MULTI_ARCH 3 to 1
- Organization: Axis Communications AB
- References: <3C21FD73.449314AA@axis.com> <3C220BBE.8010207@cygnus.com>
Andrew Cagney wrote:
>
> Don't worry, a few other targets had this as well. Yes, fine.
Ok, committed along with with my other changes that needed it. Thanks.
2001-12-21 Orjan Friberg <orjanf@axis.com>
* configure.tgt: Delete CRIS from multi-arch targets.
* config/cris/tm-cris.h: New file.
* config/cris/cris.mt (TDEPFILES): Add corelow.o solib.o solib-svr4.o.
(TM_FILE): New macro.
* cris-tdep.c (cris_examine): Correct check for srp register.
(supply_gregset, fetch_core_registers,
cris_linux_svr4_fetch_link_map_offsets, cris_fpless_backtrace):
New functions.
(_initialize_cris_tdep): Add core functions and new command.
(cris_gdbarch_init): Define link map offsets.
Index: configure.tgt
===================================================================
RCS file: /cvs/src/src/gdb/configure.tgt,v
retrieving revision 1.46
diff -u -p -r1.46 configure.tgt
--- configure.tgt 2001/12/17 16:23:02 1.46
+++ configure.tgt 2001/12/21 09:52:25
@@ -302,7 +302,6 @@ esac
# map GDB target onto multi-arch support
case "${gdb_target}" in
-cris) gdb_multi_arch=yes ;;
d10v) gdb_multi_arch=yes ;;
m68hc11) gdb_multi_arch=yes ;;
mn10300) gdb_multi_arch=yes ;;
Index: cris-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/cris-tdep.c,v
retrieving revision 1.8
diff -u -p -r1.8 cris-tdep.c
--- cris-tdep.c 2001/12/19 14:14:52 1.8
+++ cris-tdep.c 2001/12/21 09:52:27
@@ -35,6 +35,10 @@ Foundation, Inc., 59 Temple Place - Suit
/* To get entry_point_address. */
#include "symfile.h"
+#include "solib.h" /* Support for shared libraries. */
+#include "solib-svr4.h" /* For struct link_map_offsets. */
+
+
enum cris_num_regs
{
/* There are no floating point registers. Used in gdbserver low-linux.c. */
@@ -512,7 +516,10 @@ cris_examine (CORE_ADDR ip, CORE_ADDR li
insn_next = read_memory_unsigned_integer (ip, sizeof (short));
ip += sizeof (short);
regno = cris_get_operand2 (insn_next);
- if (regno == (SRP_REGNUM - NUM_GENREGS))
+
+ /* This check, meant to recognize srp, used to be regno ==
+ (SRP_REGNUM - NUM_GENREGS), but that covers r11 also. */
+ if (insn_next == 0xBE7E)
{
if (frameless_p)
{
@@ -3555,6 +3562,305 @@ cris_delayed_get_disassembler (bfd_vma a
return TARGET_PRINT_INSN (addr, info);
}
+/* Copied from <asm/elf.h>. */
+typedef unsigned long elf_greg_t;
+
+/* Same as user_regs_struct struct in <asm/user.h>. */
+typedef elf_greg_t elf_gregset_t[35];
+
+/* Unpack an elf_gregset_t into GDB's register cache. */
+
+void
+supply_gregset (elf_gregset_t *gregsetp)
+{
+ int i;
+ elf_greg_t *regp = *gregsetp;
+ static char zerobuf[4] = {0};
+
+ /* The kernel dumps all 32 registers as unsigned longs, but supply_register
+ knows about the actual size of each register so that's no problem. */
+ for (i = 0; i < NUM_GENREGS + NUM_SPECREGS; i++)
+ {
+ supply_register (i, (char *)®p[i]);
+ }
+}
+
+/* Use a local version of this function to get the correct types for
+ regsets, until multi-arch core support is ready. */
+
+static void
+fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
+ int which, CORE_ADDR reg_addr)
+{
+ elf_gregset_t gregset;
+
+ switch (which)
+ {
+ case 0:
+ if (core_reg_size != sizeof (gregset))
+ {
+ warning ("wrong size gregset struct in core file");
+ }
+ else
+ {
+ memcpy (&gregset, core_reg_sect, sizeof (gregset));
+ supply_gregset (&gregset);
+ }
+
+ default:
+ /* We've covered all the kinds of registers we know about here,
+ so this must be something we wouldn't know what to do with
+ anyway. Just ignore it. */
+ break;
+ }
+}
+
+static struct core_fns cris_elf_core_fns =
+{
+ bfd_target_elf_flavour, /* core_flavour */
+ default_check_format, /* check_format */
+ default_core_sniffer, /* core_sniffer */
+ fetch_core_registers, /* core_read_registers */
+ NULL /* next */
+};
+
+/* Fetch (and possibly build) an appropriate link_map_offsets
+ structure for native Linux/CRIS targets using the struct offsets
+ defined in link.h (but without actual reference to that file).
+
+ This makes it possible to access Linux/CRIS shared libraries from a
+ GDB that was not built on an Linux/CRIS host (for cross debugging).
+
+ See gdb/solib-svr4.h for an explanation of these fields. */
+
+struct link_map_offsets *
+cris_linux_svr4_fetch_link_map_offsets (void)
+{
+ static struct link_map_offsets lmo;
+ static struct link_map_offsets *lmp = NULL;
+
+ if (lmp == NULL)
+ {
+ lmp = &lmo;
+
+ lmo.r_debug_size = 8; /* The actual size is 20 bytes, but
+ this is all we need. */
+ lmo.r_map_offset = 4;
+ lmo.r_map_size = 4;
+
+ lmo.link_map_size = 20;
+
+ lmo.l_addr_offset = 0;
+ lmo.l_addr_size = 4;
+
+ lmo.l_name_offset = 4;
+ lmo.l_name_size = 4;
+
+ lmo.l_next_offset = 12;
+ lmo.l_next_size = 4;
+
+ lmo.l_prev_offset = 16;
+ lmo.l_prev_size = 4;
+ }
+
+ return lmp;
+}
+
+static void
+cris_fpless_backtrace (char *noargs, int from_tty)
+{
+ /* Points at the instruction after the jsr (except when in innermost frame
+ where it points at the original pc). */
+ CORE_ADDR pc = 0;
+
+ /* Temporary variable, used for parsing from the start of the function that
+ the pc is in, up to the pc. */
+ CORE_ADDR tmp_pc = 0;
+ CORE_ADDR sp = 0;
+
+ /* Information about current frame. */
+ struct symtab_and_line sal;
+ char* func_name;
+
+ /* Present instruction. */
+ unsigned short insn;
+
+ /* Next instruction, lookahead. */
+ unsigned short insn_next;
+
+ /* This is to store the offset between sp at start of function and until we
+ reach push srp (if any). */
+ int sp_add_later = 0;
+ int push_srp_found = 0;
+
+ int val = 0;
+
+ /* Frame counter. */
+ int frame = 0;
+
+ /* For the innermost frame, we want to look at srp in case it's a leaf
+ function (since there's no push srp in that case). */
+ int innermost_frame = 1;
+
+ read_register_gen (PC_REGNUM, (char *) &pc);
+ read_register_gen (SP_REGNUM, (char *) &sp);
+
+ /* We make an explicit return when we can't find an outer frame. */
+ while (1)
+ {
+ /* Get file name and line number. */
+ sal = find_pc_line (pc, 0);
+
+ /* Get function name. */
+ find_pc_partial_function (pc, &func_name, (CORE_ADDR *) NULL,
+ (CORE_ADDR *) NULL);
+
+ /* Print information about current frame. */
+ printf_unfiltered ("#%i 0x%08lx in %s", frame++, pc, func_name);
+ if (sal.symtab)
+ {
+ printf_unfiltered (" at %s:%i", sal.symtab->filename, sal.line);
+ }
+ printf_unfiltered ("\n");
+
+ /* Get the start address of this function. */
+ tmp_pc = get_pc_function_start (pc);
+
+ /* Mini parser, only meant to find push sp and sub ...,sp from the start
+ of the function, up to the pc. */
+ while (tmp_pc < pc)
+ {
+ insn = read_memory_unsigned_integer (tmp_pc, sizeof (short));
+ tmp_pc += sizeof (short);
+ if (insn == 0xE1FC)
+ {
+ /* push <reg> 32 bit instruction */
+ insn_next = read_memory_unsigned_integer (tmp_pc,
+ sizeof (short));
+ tmp_pc += sizeof (short);
+
+ /* Recognize srp. */
+ if (insn_next == 0xBE7E)
+ {
+ /* For subsequent (not this one though) push or sub which
+ affects sp, adjust sp immediately. */
+ push_srp_found = 1;
+
+ /* Note: this will break if we ever encounter a
+ push vr (1 byte) or push ccr (2 bytes). */
+ sp_add_later += 4;
+ }
+ else
+ {
+ /* Some other register was pushed. */
+ if (push_srp_found)
+ {
+ sp += 4;
+ }
+ else
+ {
+ sp_add_later += 4;
+ }
+ }
+ }
+ else if (cris_get_operand2 (insn) == SP_REGNUM
+ && cris_get_mode (insn) == 0x0000
+ && cris_get_opcode (insn) == 0x000A)
+ {
+ /* subq <val>,sp */
+ val = cris_get_quick_value (insn);
+
+ if (push_srp_found)
+ {
+ sp += val;
+ }
+ else
+ {
+ sp_add_later += val;
+ }
+
+ }
+ else if (cris_get_operand2 (insn) == SP_REGNUM
+ /* Autoincrement addressing mode. */
+ && cris_get_mode (insn) == 0x0003
+ /* Opcode. */
+ && ((insn) & 0x03E0) >> 5 == 0x0004)
+ {
+ /* subu <val>,sp */
+ val = get_data_from_address (&insn, tmp_pc);
+
+ if (push_srp_found)
+ {
+ sp += val;
+ }
+ else
+ {
+ sp_add_later += val;
+ }
+ }
+ else if (cris_get_operand2 (insn) == SP_REGNUM
+ && ((insn & 0x0F00) >> 8) == 0x0001
+ && (cris_get_signed_offset (insn) < 0))
+ {
+ /* Immediate byte offset addressing prefix word with sp as base
+ register. Used for CRIS v8 i.e. ETRAX 100 and newer if <val>
+ is between 64 and 128.
+ movem r<regsave>,[sp=sp-<val>] */
+ val = -cris_get_signed_offset (insn);
+ insn_next = read_memory_unsigned_integer (tmp_pc,
+ sizeof (short));
+ tmp_pc += sizeof (short);
+
+ if (cris_get_mode (insn_next) == PREFIX_ASSIGN_MODE
+ && cris_get_opcode (insn_next) == 0x000F
+ && cris_get_size (insn_next) == 0x0003
+ && cris_get_operand1 (insn_next) == SP_REGNUM)
+ {
+ if (push_srp_found)
+ {
+ sp += val;
+ }
+ else
+ {
+ sp_add_later += val;
+ }
+ }
+ }
+ }
+
+ if (push_srp_found)
+ {
+ /* Reset flag. */
+ push_srp_found = 0;
+
+ /* sp should now point at where srp is stored on the stack. Update
+ the pc to the srp. */
+ pc = read_memory_unsigned_integer (sp, 4);
+ }
+ else if (innermost_frame)
+ {
+ /* We couldn't find a push srp in the prologue, so this must be
+ a leaf function, and thus we use the srp register directly.
+ This should happen at most once, for the innermost function. */
+ read_register_gen (SRP_REGNUM, (char *) &pc);
+ }
+ else
+ {
+ /* Couldn't find an outer frame. */
+ return;
+ }
+
+ /* Reset flag. (In case the innermost frame wasn't a leaf, we don't
+ want to look at the srp register later either). */
+ innermost_frame = 0;
+
+ /* Now, add the offset for everything up to, and including push srp,
+ that was held back during the prologue parsing. */
+ sp += sp_add_later;
+ sp_add_later = 0;
+ }
+}
+
void
_initialize_cris_tdep (void)
{
@@ -3583,6 +3889,14 @@ _initialize_cris_tdep (void)
"Set the current CRIS ABI version.", &setlist);
c->function.sfunc = cris_abi_update;
add_show_from_set (c, &showlist);
+
+ c = add_cmd ("cris-fpless-backtrace", class_support, cris_fpless_backtrace,
+ "Display call chain using the subroutine return pointer.\n"
+ "Note that this displays the address after the jump to the "
+ "subroutine.", &cmdlist);
+
+ add_core_fns (&cris_elf_core_fns);
+
}
/* Prints out all target specific values. */
@@ -3997,5 +4311,9 @@ cris_gdbarch_init (struct gdbarch_info i
/* Helpful for backtracing and returning in a call dummy. */
set_gdbarch_save_dummy_frame_tos (gdbarch, generic_save_dummy_frame_tos);
+ /* Use target_specific function to define link map offsets. */
+ set_solib_svr4_fetch_link_map_offsets
+ (gdbarch, cris_linux_svr4_fetch_link_map_offsets);
+
return gdbarch;
}
Index: config/cris/tm-cris.h
===================================================================
RCS file: tm-cris.h
diff -N tm-cris.h
--- /dev/null Tue May 5 13:32:27 1998
+++ tm-cris.h Fri Dec 21 01:52:27 2001
@@ -0,0 +1,2 @@
+#define GDB_MULTI_ARCH 1
+#include "solib.h"
Index: config/cris/cris.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/cris/cris.mt,v
retrieving revision 1.1
diff -u -p -r1.1 cris.mt
--- cris.mt 2001/07/16 08:52:41 1.1
+++ cris.mt 2001/12/21 09:52:27
@@ -1 +1,2 @@
-TDEPFILES= cris-tdep.o
+TDEPFILES= cris-tdep.o corelow.o solib.o solib-svr4.o
+TM_FILE= tm-cris.h
--
Orjan Friberg
Axis Communications AB