bedbug.c.svn-base

u-boot loader common files, like cpu, clock, environment...etc...

	} else if (strcmp (name, "tbl") == 0)
		val = 268;
	else if (strcmp (name, "tbu") == 0)
		val = 269;
	else
		return 0;

	/* tbr is a 10 bit field whose interpretation has the high and low
	   five-bit fields reversed from their encoding in the operand */

	val = htonl (val);
	tbr = ((val >> 5) & 0x1f) | ((val & 0x1f) << 5);
	return tbr;
}								/* tbr_name */



/*======================================================================
 * The next several functions (handle_xxx) are the routines that handle
 * disassembling the opcodes with simplified mnemonics.
 *
 * Arguments:
 *	ctx		A pointer to the disassembler context record.
 *
 * Returns TRUE if the simpler form was printed or FALSE if it was not.
 */

int handle_bc (struct ppc_ctx *ctx)
{
	unsigned long bo;
	unsigned long bi;
	static struct opcode blt = { B_OPCODE (16, 0, 0), B_MASK, {O_BD, 0},
	0, "blt", H_RELATIVE
	};
	static struct opcode bne =
			{ B_OPCODE (16, 0, 0), B_MASK, {O_cr2, O_BD, 0},
	0, "bne", H_RELATIVE
	};
	static struct opcode bdnz = { B_OPCODE (16, 0, 0), B_MASK, {O_BD, 0},
	0, "bdnz", H_RELATIVE
	};

  /*------------------------------------------------------------*/

	if (get_operand_value (ctx->op, ctx->instr, O_BO, &bo) == FALSE)
		return FALSE;

	if (get_operand_value (ctx->op, ctx->instr, O_BI, &bi) == FALSE)
		return FALSE;

	if ((bo == 12) && (bi == 0)) {
		ctx->op = &blt;
		sprintf (&ctx->data[ctx->datalen], "%-7s ", ctx->op->name);
		ctx->datalen += 8;
		print_operands (ctx);
		return TRUE;
	} else if ((bo == 4) && (bi == 10)) {
		ctx->op = &bne;
		sprintf (&ctx->data[ctx->datalen], "%-7s ", ctx->op->name);
		ctx->datalen += 8;
		print_operands (ctx);
		return TRUE;
	} else if ((bo == 16) && (bi == 0)) {
		ctx->op = &bdnz;
		sprintf (&ctx->data[ctx->datalen], "%-7s ", ctx->op->name);
		ctx->datalen += 8;
		print_operands (ctx);
		return TRUE;
	}

	return FALSE;
}								/* handle_blt */



/*======================================================================
 * Outputs source line information for the disassembler.  This should
 * be modified in the future to lookup the actual line of source code
 * from the file, but for now this will do.
 *
 * Arguments:
 *	filename	The address of a character array containing the
 *			absolute path and file name of the source file.
 *
 *	funcname	The address of a character array containing the
 *			name of the function (not C++ demangled (yet))
 *			to which this code belongs.
 *
 *	line_no		An integer specifying the source line number that
 *			generated this code.
 *
 *	pfunc		The address of a function to call to print the output.
 *
 *
 * Returns TRUE if it was able to output the line info, or false if it was
 * not.
 */

int print_source_line (char *filename, char *funcname,
					   int line_no, int (*pfunc) (const char *))
{
	char out_buf[256];

  /*------------------------------------------------------------*/

	(*pfunc) ("");				/* output a newline */
	sprintf (out_buf, "%s %s(): line %d", filename, funcname, line_no);
	(*pfunc) (out_buf);

	return TRUE;
}								/* print_source_line */



/*======================================================================
 * Entry point for the PPC assembler.
 *
 * Arguments:
 *	asm_buf		An array of characters containing the assembly opcode
 *			and operands to convert to a POWERPC machine
 *			instruction.
 *
 * Returns the machine instruction or zero.
 */

unsigned long asmppc (unsigned long memaddr, char *asm_buf, int *err)
{
	struct opcode *opc;
	struct operand *oper[MAX_OPERANDS];
	unsigned long instr;
	unsigned long param;
	char *ptr = asm_buf;
	char scratch[20];
	int i;
	int w_operands = 0;			/* wanted # of operands */
	int n_operands = 0;			/* # of operands read */
	int asm_debug = 0;

  /*------------------------------------------------------------*/

	if (err)
		*err = 0;

	if (get_word (&ptr, scratch) == 0)
		return 0;

	/* Lookup the opcode structure based on the opcode name */
	if ((opc = find_opcode_by_name (scratch)) == (struct opcode *) 0) {
		if (err)
			*err = E_ASM_BAD_OPCODE;
		return 0;
	}

	if (asm_debug) {
		printf ("asmppc: Opcode = \"%s\"\n", opc->name);
	}

	for (i = 0; i < 8; ++i) {
		if (opc->fields[i] == 0)
			break;
		++w_operands;
	}

	if (asm_debug) {
		printf ("asmppc: Expecting %d operands\n", w_operands);
	}

	instr = opc->opcode;

	/* read each operand */
	while (n_operands < w_operands) {

		oper[n_operands] = &operands[opc->fields[n_operands] - 1];

		if (oper[n_operands]->hint & OH_SILENT) {
			/* Skip silent operands, they are covered in opc->opcode */

			if (asm_debug) {
				printf ("asmppc: Operand %d \"%s\" SILENT\n", n_operands,
						oper[n_operands]->name);
			}

			++n_operands;
			continue;
		}

		if (get_word (&ptr, scratch) == 0)
			break;

		if (asm_debug) {
			printf ("asmppc: Operand %d \"%s\" : \"%s\"\n", n_operands,
					oper[n_operands]->name, scratch);
		}

		if ((param = parse_operand (memaddr, opc, oper[n_operands],
									scratch, err)) == -1)
			return 0;

		instr |= param;
		++n_operands;
	}

	if (n_operands < w_operands) {
		if (err)
			*err = E_ASM_NUM_OPERANDS;
		return 0;
	}

	if (asm_debug) {
		printf ("asmppc: Instruction = 0x%08lx\n", instr);
	}

	return instr;
}								/* asmppc */



/*======================================================================
 * Called by the assembler to interpret a single operand
 *
 * Arguments:
 *	ctx		A pointer to the disassembler context record.
 *
 * Returns 0 if the operand is ok, or -1 if it is bad.
 */

int parse_operand (unsigned long memaddr, struct opcode *opc,
				   struct operand *oper, char *txt, int *err)
{
	long data;
	long mask;
	int is_neg = 0;

  /*------------------------------------------------------------*/

	mask = (1 << oper->bits) - 1;

	if (oper->hint & OH_ADDR) {
		data = read_number (txt);

		if (opc->hint & H_RELATIVE)
			data = data - memaddr;

		if (data < 0)
			is_neg = 1;

		data >>= 2;
		data &= (mask >> 1);

		if (is_neg)
			data |= 1 << (oper->bits - 1);
	}

	else if (oper->hint & OH_REG) {
		if (txt[0] == 'r' || txt[0] == 'R')
			txt++;
		else if (txt[0] == '%' && (txt[1] == 'r' || txt[1] == 'R'))
			txt += 2;

		data = read_number (txt);
		if (data > 31) {
			if (err)
				*err = E_ASM_BAD_REGISTER;
			return -1;
		}

		data = htonl (data);
	}

	else if (oper->hint & OH_SPR) {
		if ((data = spr_value (txt)) == 0) {
			if (err)
				*err = E_ASM_BAD_SPR;
			return -1;
		}
	}

	else if (oper->hint & OH_TBR) {
		if ((data = tbr_value (txt)) == 0) {
			if (err)
				*err = E_ASM_BAD_TBR;
			return -1;
		}
	}

	else {
		data = htonl (read_number (txt));
	}

	return (data & mask) << oper->shift;
}								/* parse_operand */


char *asm_error_str (int err)
{
	switch (err) {
	case E_ASM_BAD_OPCODE:
		return "Bad opcode";
	case E_ASM_NUM_OPERANDS:
		return "Bad number of operands";
	case E_ASM_BAD_REGISTER:
		return "Bad register number";
	case E_ASM_BAD_SPR:
		return "Bad SPR name or number";
	case E_ASM_BAD_TBR:
		return "Bad TBR name or number";
	}

	return "";
}								/* asm_error_str */



/*======================================================================
 * Copy a word from one buffer to another, ignores leading white spaces.
 *
 * Arguments:
 *	src		The address of a character pointer to the
 *			source buffer.
 *	dest		A pointer to a character buffer to write the word
 *			into.
 *
 * Returns the number of non-white space characters copied, or zero.
 */

int get_word (char **src, char *dest)
{
	char *ptr = *src;
	int nchars = 0;

  /*------------------------------------------------------------*/

	/* Eat white spaces */
	while (*ptr && isblank (*ptr))
		ptr++;

	if (*ptr == 0) {
		*src = ptr;
		return 0;
	}

	/* Find the text of the word */
	while (*ptr && !isblank (*ptr) && (*ptr != ','))
		dest[nchars++] = *ptr++;
	ptr = (*ptr == ',') ? ptr + 1 : ptr;
	dest[nchars] = 0;

	*src = ptr;
	return nchars;
}								/* get_word */



/*======================================================================
 * Convert a numeric string to a number, be aware of base notations.
 *
 * Arguments:
 *	txt		The numeric string.
 *
 * Returns the converted numeric value.
 */

long read_number (char *txt)
{
	long val;
	int is_neg = 0;

  /*------------------------------------------------------------*/

	if (txt == 0 || *txt == 0)
		return 0;

	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 */