/* Target-machine dependent code for the Intel 960
- Copyright (C) 1991 Free Software Foundation, Inc.
+ Copyright 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
Contributed by Intel Corporation.
examine_prologue and other parts contributed by Wind River Systems.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "symtab.h"
#include "frame.h"
#include "floatformat.h"
#include "target.h"
+#include "gdbcore.h"
+
+static CORE_ADDR next_insn PARAMS ((CORE_ADDR memaddr,
+ unsigned int *pword1,
+ unsigned int *pword2));
/* gdb960 is always running on a non-960 host. Check its characteristics.
This routine must be called as part of gdb initialization. */
}
}
-/* Initialization stub */
+/****************************************/
+/* MEM format */
+/****************************************/
+
+struct tabent {
+ char *name;
+ char numops;
+};
+
+static int /* returns instruction length: 4 or 8 */
+mem( memaddr, word1, word2, noprint )
+ unsigned long memaddr;
+ unsigned long word1, word2;
+ int noprint; /* If TRUE, return instruction length, but
+ don't output any text. */
+{
+ int i, j;
+ int len;
+ int mode;
+ int offset;
+ const char *reg1, *reg2, *reg3;
+
+ /* This lookup table is too sparse to make it worth typing in, but not
+ * so large as to make a sparse array necessary. We allocate the
+ * table at runtime, initialize all entries to empty, and copy the
+ * real ones in from an initialization table.
+ *
+ * NOTE: In this table, the meaning of 'numops' is:
+ * 1: single operand
+ * 2: 2 operands, load instruction
+ * -2: 2 operands, store instruction
+ */
+ static struct tabent *mem_tab = NULL;
+/* Opcodes of 0x8X, 9X, aX, bX, and cX must be in the table. */
+#define MEM_MIN 0x80
+#define MEM_MAX 0xcf
+#define MEM_SIZ ((MEM_MAX-MEM_MIN+1) * sizeof(struct tabent))
+
+ static struct { int opcode; char *name; char numops; } mem_init[] = {
+ 0x80, "ldob", 2,
+ 0x82, "stob", -2,
+ 0x84, "bx", 1,
+ 0x85, "balx", 2,
+ 0x86, "callx", 1,
+ 0x88, "ldos", 2,
+ 0x8a, "stos", -2,
+ 0x8c, "lda", 2,
+ 0x90, "ld", 2,
+ 0x92, "st", -2,
+ 0x98, "ldl", 2,
+ 0x9a, "stl", -2,
+ 0xa0, "ldt", 2,
+ 0xa2, "stt", -2,
+ 0xb0, "ldq", 2,
+ 0xb2, "stq", -2,
+ 0xc0, "ldib", 2,
+ 0xc2, "stib", -2,
+ 0xc8, "ldis", 2,
+ 0xca, "stis", -2,
+ 0, NULL, 0
+ };
+
+ if ( mem_tab == NULL ){
+ mem_tab = (struct tabent *) xmalloc( MEM_SIZ );
+ memset( mem_tab, '\0', MEM_SIZ );
+ for ( i = 0; mem_init[i].opcode != 0; i++ ){
+ j = mem_init[i].opcode - MEM_MIN;
+ mem_tab[j].name = mem_init[i].name;
+ mem_tab[j].numops = mem_init[i].numops;
+ }
+ }
+
+ i = ((word1 >> 24) & 0xff) - MEM_MIN;
+ mode = (word1 >> 10) & 0xf;
+
+ if ( (mem_tab[i].name != NULL) /* Valid instruction */
+ && ((mode == 5) || (mode >=12)) ){ /* With 32-bit displacement */
+ len = 8;
+ } else {
+ len = 4;
+ }
+
+ if ( noprint ){
+ return len;
+ }
+ abort ();
+}
+
+/* Read the i960 instruction at 'memaddr' and return the address of
+ the next instruction after that, or 0 if 'memaddr' is not the
+ address of a valid instruction. The first word of the instruction
+ is stored at 'pword1', and the second word, if any, is stored at
+ 'pword2'. */
+
+static CORE_ADDR
+next_insn (memaddr, pword1, pword2)
+ unsigned int *pword1, *pword2;
+ CORE_ADDR memaddr;
+{
+ int len;
+ char buf[8];
+
+ /* Read the two (potential) words of the instruction at once,
+ to eliminate the overhead of two calls to read_memory ().
+ FIXME: Loses if the first one is readable but the second is not
+ (e.g. last word of the segment). */
+
+ read_memory (memaddr, buf, 8);
+ *pword1 = extract_unsigned_integer (buf, 4);
+ *pword2 = extract_unsigned_integer (buf + 4, 4);
+
+ /* Divide instruction set into classes based on high 4 bits of opcode*/
+
+ switch ((*pword1 >> 28) & 0xf)
+ {
+ case 0x0:
+ case 0x1: /* ctrl */
+
+ case 0x2:
+ case 0x3: /* cobr */
+
+ case 0x5:
+ case 0x6:
+ case 0x7: /* reg */
+ len = 4;
+ break;
+
+ case 0x8:
+ case 0x9:
+ case 0xa:
+ case 0xb:
+ case 0xc:
+ len = mem (memaddr, *pword1, *pword2, 1);
+ break;
+
+ default: /* invalid instruction */
+ len = 0;
+ break;
+ }
+
+ if (len)
+ return memaddr + len;
+ else
+ return 0;
+}
+
+/* 'start_frame' is a variable in the MON960 runtime startup routine
+ that contains the frame pointer of the 'start' routine (the routine
+ that calls 'main'). By reading its contents out of remote memory,
+ we can tell where the frame chain ends: backtraces should halt before
+ they display this frame. */
+
+int
+mon960_frame_chain_valid (chain, curframe)
+ unsigned int chain;
+ struct frame_info *curframe;
+{
+ struct symbol *sym;
+ struct minimal_symbol *msymbol;
+
+ /* crtmon960.o is an assembler module that is assumed to be linked
+ * first in an i80960 executable. It contains the true entry point;
+ * it performs startup up initialization and then calls 'main'.
+ *
+ * 'sf' is the name of a variable in crtmon960.o that is set
+ * during startup to the address of the first frame.
+ *
+ * 'a' is the address of that variable in 80960 memory.
+ */
+ static char sf[] = "start_frame";
+ CORE_ADDR a;
+
+
+ chain &= ~0x3f; /* Zero low 6 bits because previous frame pointers
+ contain return status info in them. */
+ if ( chain == 0 ){
+ return 0;
+ }
+
+ sym = lookup_symbol(sf, 0, VAR_NAMESPACE, (int *)NULL,
+ (struct symtab **)NULL);
+ if ( sym != 0 ){
+ a = SYMBOL_VALUE (sym);
+ } else {
+ msymbol = lookup_minimal_symbol (sf, NULL, NULL);
+ if (msymbol == NULL)
+ return 0;
+ a = SYMBOL_VALUE_ADDRESS (msymbol);
+ }
+
+ return ( chain != read_memory_integer(a,4) );
+}
void
_initialize_i960_tdep ()
{
check_host ();
+
+ tm_print_insn = print_insn_i960;
}
projects / deliverable / binutils-gdb.git / blobdiff