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if (*txt == '-') {
is_neg = 1;
++txt;
}
if (txt[0] == '0' && (txt[1] == 'x' || txt[1] == 'X')) /* hex */
val = simple_strtoul (&txt[2], NULL, 16);
else /* decimal */
val = simple_strtoul (txt, NULL, 10);
if (is_neg)
val = -val;
return val;
} /* read_number */
int downstring (char *s)
{
if (!s || !*s)
return 0;
while (*s) {
if (isupper (*s))
*s = tolower (*s);
s++;
}
return 0;
} /* downstring */
/*======================================================================
* Examines the instruction at the current address and determines the
* next address to be executed. This will take into account branches
* of different types so that a "step" and "next" operations can be
* supported.
*
* Arguments:
* nextaddr The address (to be filled in) of the next
* instruction to execute. This will only be a valid
* address if TRUE is returned.
*
* step_over A flag indicating how to compute addresses for
* branch statements:
* TRUE = Step over the branch (next)
* FALSE = step into the branch (step)
*
* Returns TRUE if it was able to compute the address. Returns FALSE if
* it has a problem reading the current instruction or one of the registers.
*/
int find_next_address (unsigned char *nextaddr, int step_over,
struct pt_regs *regs)
{
unsigned long pc; /* SRR0 register from PPC */
unsigned long ctr; /* CTR register from PPC */
unsigned long cr; /* CR register from PPC */
unsigned long lr; /* LR register from PPC */
unsigned long instr; /* instruction at SRR0 */
unsigned long next; /* computed instruction for 'next' */
unsigned long step; /* computed instruction for 'step' */
unsigned long addr = 0; /* target address operand */
unsigned long aa = 0; /* AA operand */
unsigned long lk = 0; /* LK operand */
unsigned long bo = 0; /* BO operand */
unsigned long bi = 0; /* BI operand */
struct opcode *op = 0; /* opcode structure for 'instr' */
int ctr_ok = 0;
int cond_ok = 0;
int conditional = 0;
int branch = 0;
/*------------------------------------------------------------*/
if (nextaddr == 0 || regs == 0) {
printf ("find_next_address: bad args");
return FALSE;
}
pc = regs->nip & 0xfffffffc;
instr = INSTRUCTION (pc);
if ((op = find_opcode (instr)) == (struct opcode *) 0) {
printf ("find_next_address: can't parse opcode 0x%lx", instr);
return FALSE;
}
ctr = regs->ctr;
cr = regs->ccr;
lr = regs->link;
switch (op->opcode) {
case B_OPCODE (16, 0, 0): /* bc */
case B_OPCODE (16, 0, 1): /* bcl */
case B_OPCODE (16, 1, 0): /* bca */
case B_OPCODE (16, 1, 1): /* bcla */
if (!get_operand_value (op, instr, O_BD, &addr) ||
!get_operand_value (op, instr, O_BO, &bo) ||
!get_operand_value (op, instr, O_BI, &bi) ||
!get_operand_value (op, instr, O_AA, &aa) ||
!get_operand_value (op, instr, O_LK, &lk))
return FALSE;
if ((addr & (1 << 13)) != 0)
addr = addr - (1 << 14);
addr <<= 2;
conditional = 1;
branch = 1;
break;
case I_OPCODE (18, 0, 0): /* b */
case I_OPCODE (18, 0, 1): /* bl */
case I_OPCODE (18, 1, 0): /* ba */
case I_OPCODE (18, 1, 1): /* bla */
if (!get_operand_value (op, instr, O_LI, &addr) ||
!get_operand_value (op, instr, O_AA, &aa) ||
!get_operand_value (op, instr, O_LK, &lk))
return FALSE;
if ((addr & (1 << 23)) != 0)
addr = addr - (1 << 24);
addr <<= 2;
conditional = 0;
branch = 1;
break;
case XL_OPCODE (19, 528, 0): /* bcctr */
case XL_OPCODE (19, 528, 1): /* bcctrl */
if (!get_operand_value (op, instr, O_BO, &bo) ||
!get_operand_value (op, instr, O_BI, &bi) ||
!get_operand_value (op, instr, O_LK, &lk))
return FALSE;
addr = ctr;
aa = 1;
conditional = 1;
branch = 1;
break;
case XL_OPCODE (19, 16, 0): /* bclr */
case XL_OPCODE (19, 16, 1): /* bclrl */
if (!get_operand_value (op, instr, O_BO, &bo) ||
!get_operand_value (op, instr, O_BI, &bi) ||
!get_operand_value (op, instr, O_LK, &lk))
return FALSE;
addr = lr;
aa = 1;
conditional = 1;
branch = 1;
break;
default:
conditional = 0;
branch = 0;
break;
}
if (conditional) {
switch ((bo & 0x1e) >> 1) {
case 0: /* 0000y */
if (--ctr != 0)
ctr_ok = 1;
cond_ok = !(cr & (1 << (31 - bi)));
break;
case 1: /* 0001y */
if (--ctr == 0)
ctr_ok = 1;
cond_ok = !(cr & (1 << (31 - bi)));
break;
case 2: /* 001zy */
ctr_ok = 1;
cond_ok = !(cr & (1 << (31 - bi)));
break;
case 4: /* 0100y */
if (--ctr != 0)
ctr_ok = 1;
cond_ok = cr & (1 << (31 - bi));
break;
case 5: /* 0101y */
if (--ctr == 0)
ctr_ok = 1;
cond_ok = cr & (1 << (31 - bi));
break;
case 6: /* 011zy */
ctr_ok = 1;
cond_ok = cr & (1 << (31 - bi));
break;
case 8: /* 1z00y */
if (--ctr != 0)
ctr_ok = cond_ok = 1;
break;
case 9: /* 1z01y */
if (--ctr == 0)
ctr_ok = cond_ok = 1;
break;
case 10: /* 1z1zz */
ctr_ok = cond_ok = 1;
break;
}
}
if (branch && (!conditional || (ctr_ok && cond_ok))) {
if (aa)
step = addr;
else
step = addr + pc;
if (lk)
next = pc + 4;
else
next = step;
} else {
step = next = pc + 4;
}
if (step_over == TRUE)
*(unsigned long *) nextaddr = next;
else
*(unsigned long *) nextaddr = step;
return TRUE;
} /* find_next_address */
/*
* Copyright (c) 2000 William L. Pitts and W. Gerald Hicks
* All rights reserved.
*
* Redistribution and use in source and binary forms are freely
* permitted provided that the above copyright notice and this
* paragraph and the following disclaimer are duplicated in all
* such forms.
*
* This software is provided "AS IS" and without any express or
* implied warranties, including, without limitation, the implied
* warranties of merchantability and fitness for a particular
* purpose.
*/
#endif /* CONFIG_COMMANDS & CFG_CMD_BEDBUG */