post1.s

U BOOT源码

	blr				/* Return to calling function */


/****************************************************
 ********             fill test              ********
 ***************************************************/
/*	tests memory by filling with value, and reading back */
/*	r5 = Size of memory in bytes */
/*	r4 = Value to write */
/*	r3 = Error code */
fill_test:
	mflr    r0                      /* Get link register */
	stwu    r1, -32(r1)             /* Save back chain and move SP */
	stw     r0, +36(r1)             /* Save link register */
	stmw    r27, 8(r1)              /* save r27 - r31 on stack */
					/* r31 - scratch register */
					/* r30 - memory address */
	mr	r27, r3
	mr	r28, r4
	mr	r29, r5

	WATCHDOG_RESET   		/* Reset the watchdog */

	/* first fill memory with Value */
	srawi	r31, r29, 2		/* convert bytes to longs */
	mtctr	r31			/* setup counter */
	addi	r30, 0, 0		/* Make r30 = addr 0 */
ft_0:	stw	r28, 0(r30)		/* Store value */
	addi	r30, r30, 4		/* Increment to next word */
	andi.	r31, r30, 0xffff	/* check for 2^16 loops */
	bne	ft_0a			/* if not there, then skip */
	WATCHDOG_RESET   		/* kick the dog every now and then */
ft_0a:	bdnz	ft_0			/* Round and round... */

	WATCHDOG_RESET   		/* Reset the watchdog */

	/* Now confirm Value is in memory */
	srawi	r31, r29, 2		/* convert bytes to longs */
	mtctr	r31			/* setup counter */
	addi	r30, 0, 0		/* Make r30 = addr 0 */
ft_1:	lwz	r31, 0(r30)		/* get value from memory */
	xor.	r31, r31, r28		/* Writen = Read ? */
	bne	ft_err			/* If bad, than halt */
	addi	r30, r30, 4		/* Increment to next word */
	andi.	r31, r30, 0xffff	/* check for 2^16 loops*/
	bne	ft_1a			/* if not there, then skip */
	WATCHDOG_RESET			/* kick the dog every now and then */
ft_1a:	bdnz	ft_1			/* Round and round... */

	WATCHDOG_RESET   		/* Reset the watchdog */

	b	fill_done		/* restore and return */

ft_err:	addi	r29, r27, 0		/* save current led code */
	addi	r27, r31, 0		/* get pattern in r27 */
	bl	get_idx			/* get index from r27 */
	add	r27, r27, r29		/* add index to old led code */
	bl	log_err			/* output led err code, halt CPU */

fill_done:
	lmw     r27, 8(r1)              /* restore r27 - r31 from stack */
	lwz     r0, +36(r1)             /* Get saved link register */
	addi    r1, r1, +32             /* Remove frame from stack */
	mtlr    r0                      /* Restore link register */
	blr                             /* Return to calling function */


/****************************************************
 *******  get error index from r3 pattern    ********
 ***************************************************/
get_idx:				/* r3 = (MSW(r3) !=0)*2 +
					    (LSW(r3) !=0) */
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -12(r1)		/* Save back chain and move SP */
	stw	r0, +16(r1)		/* Save link register */
	stw	r4, +8(r1)		/* save R4 */

	andi.	r4, r3, 0xffff		/* check for lower bits */
	beq	gi2			/* skip if no bits set */
	andis.	r4, r3, 0xffff		/* check for upper bits */
	beq	gi3			/* skip if no bits set */
	addi	r3, 0, 3		/* both upper and lower bits set */
	b	gi_done
gi2:	andis.	r4, r3, 0xffff		/* check for upper bits*/
	beq	gi4			/* skip if no bits set */
	addi	r3, 0, 2		/* only upper bits set */
	b	gi_done
gi3:	addi	r3, 0, 1		/* only lower bits set */
	b	gi_done
gi4:	addi	r3, 0, 0		/* no bits set */
gi_done:
	/* restore stack and return */
	lwz	r0, +16(r1)		/* Get saved link register */
	mtlr	r0			/* Restore link register */
	lwz	r4, +8(r1)		/* restore r4 */
	addi	r1, r1, +12		/* Remove frame from stack */
	blr				/* Return to calling function */

/****************************************************
 ********       set LED to R5 and hang       ********
 ***************************************************/
log_stat:				/* output a led code and continue */
set_led:
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -12(r1)		/* Save back chain and move SP */
	stw	r0, +16(r1)		/* Save link register */
	stw	r4, +8(r1)		/* save R4 */

	addis	r4, 0, 0xfe00		/* LED buffer is at 0xfe000000 */
#if defined(CONFIG_W7OLMG)		/* only on gateway, invert outputs */
	xori	r3,r3, 0xffff		/* complement led code, active low */
	sth	r3, 0(r4)		/* store first test value */
	xori	r3,r3, 0xffff		/* complement led code, active low */
#else					/* if not gateway, then don't invert */
	sth	r3, 0(r4)		/* store first test value */
#endif

	/* restore stack and return */
	lwz	r0, +16(r1)		/* Get saved link register */
	mtlr	r0			/* Restore link register */
	lwz	r4, +8(r1)		/* restore r4 */
	addi	r1, r1, +12		/* Remove frame from stack */
	blr				/* Return to calling function */

get_led:
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -12(r1)		/* Save back chain and move SP */
	stw	r0, +16(r1)		/* Save link register */
	stw	r4, +8(r1)		/* save R4 */

	addis	r4, 0, 0xfe00		/* LED buffer is at 0xfe000000 */
	lhz	r3, 0(r4)		/* store first test value */
#if defined(CONFIG_W7OLMG)		/* only on gateway, invert inputs */
	xori	r3,r3, 0xffff		/* complement led code, active low */
#endif

	/* restore stack and return */
	lwz	r0, +16(r1)		/* Get saved link register */
	mtlr	r0			/* Restore link register */
	lwz	r4, +8(r1)		/* restore r4 */
	addi	r1, r1, +12		/* Remove frame from stack */
	blr				/* Return to calling function */

log_err:	/* output the error and hang the board ( for now ) */
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -12(r1)		/* Save back chain and move SP */
	stw	r0, +16(r1)		/* Save link register */
	stw	r3, +8(r1)		/* save a copy of error code */
	bl	set_led			/* set the led pattern */
	GET_GOT				/* get GOT address in r14 */
	lwz	r3,GOT(err_str)		/* get address of string */
	bl	post_puts		/* output the warning string */
	lwz	r3, +8(r1)		/* get error code */
	addi	r4, 0, 2		/* set disp length to 2 nibbles */
	bl	disp_hex		/* output the error code */
	lwz	r3,GOT(end_str)		/* get address of string */
	bl	post_puts		/* output the warning string */
halt:
	b	halt			/* hang */

	/* restore stack and return */
	lwz	r0, +16(r1)		/* Get saved link register */
	mtlr	r0			/* Restore link register */
	addi	r1, r1, +12		/* Remove frame from stack */
	blr				/* Return to calling function */

log_warn:	/* output a warning, then continue with operations */
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -16(r1)		/* Save back chain and move SP */
	stw	r0, +20(r1)		/* Save link register */
	stw	r3, +8(r1)		/* save a copy of error code */
	stw	r14, +12(r1)		/* save a copy of r14 (used by GOT) */

	bl	set_led			/* set the led pattern */
	GET_GOT				/* get GOT address in r14 */
	lwz	r3,GOT(warn_str)	/* get address of string */
	bl	post_puts		/* output the warning string */
	lwz	r3, +8(r1)		/* get error code */
	addi	r4, 0, 2		/* set disp length to 2 nibbles */
	bl	disp_hex		/* output the error code */
	lwz	r3,GOT(end_str)		/* get address of string */
	bl	post_puts		/* output the warning string */

	addis	r3, 0, 64		/* has a long delay */
	mtctr	r3
log_2:
	WATCHDOG_RESET			/* this keeps dog from barking, */
					/*   and takes time */
	bdnz	log_2			/* loop till time expires */

	/* restore stack and return */
	lwz	r0, +20(r1)		/* Get saved link register */
	lwz	r14, +12(r1)		/* restore r14 */
	mtlr	r0			/* Restore link register */
	addi	r1, r1, +16		/* Remove frame from stack */
	blr				/* Return to calling function */

/*******************************************************************
 *	temp_uart_init
 *	Temporary UART initialization routine
 *	Sets up UART0 to run at 9600N81 off of the internal clock.
 *	R3-R4 are used.
 ******************************************************************/
temp_uart_init:
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -8(r1)		/* Save back chain and move SP */
	stw	r0, +12(r1)		/* Save link register */

	addis   r3, 0, 0xef60
	ori     r3, r3, 0x0303          /* r3 = UART0_LCR */
	addi    r4, 0, 0x83             /* n81 format, divisor regs enabled */
	stb     r4, 0(r3)

	/* set baud rate to use internal clock,
	   baud = (200e6/16)/31/42 = 9600 */

	addis   r3, 0, 0xef60		/* Address of baud divisor reg */
	ori     r3, r3, 0x0300		/*   UART0_DLM */
	addi    r4, 0, +42		/* uart baud divisor LSB = 93 */
	stb     r4, 0(r3)               /* baud = (200 /16)/14/93 */

	addi    r3, r3, 0x0001		/* uart baud divisor addr */
	addi    r4, 0, 0
	stb     r4, 0(r3)               /* Divisor Latch MSB = 0 */

	addis   r3, 0, 0xef60
	ori     r3, r3, 0x0303          /* r3 = UART0_LCR */
	addi    r4, 0, 0x03             /* n81 format, tx/rx regs enabled */
	stb     r4, 0(r3)

	/* output a few line feeds */
	addi	r3, 0, '\n'		/* load line feed */
	bl 	post_putc		/* output the char */
	addi	r3, 0, '\n'		/* load line feed */
	bl 	post_putc		/* output the char */

	/* restore stack and return */
	lwz	r0, +12(r1)		/* Get saved link register */
	mtlr	r0			/* Restore link register */
	addi	r1, r1, +8		/* Remove frame from stack */
	blr				/* Return to calling function */

/**********************************************************************
 **	post_putc
 **	outputs charactor in R3
 **	r3 returns the error code ( -1 if there is an error )
 *********************************************************************/

post_putc:

	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -20(r1)		/* Save back chain and move SP */
	stw	r0, +24(r1)		/* Save link register */
	stmw	r29, 8(r1)		/* save	r29 - r31 on stack
					   r31 - uart base address
					   r30 - delay counter
					   r29 - scratch reg */

     addis   r31, 0, 0xef60		/* Point to uart base */
     ori     r31, r31, 0x0300
     addis   r30, 0, 152 		/* Load about 10,000,000 ticks. */
pputc_lp:
	lbz     r29, 5(r31) 		/* Read Line Status Register */
	andi.   r29, r29, 0x20		/* Check THRE status */
	bne     thre_set		/* Branch if FIFO empty */
	addic.  r30, r30, -1		/* Decrement and check if empty. */
	bne     pputc_lp		/* Try, try again */
	addi    r3, 0, -1		/* Load error code for timeout */
	b       pputc_done 		/* Bail out with error code set */
thre_set:
	stb     r3, 0(r31)		/* Store character to UART */
	addi	r3, 0, 0		/* clear error code */
pputc_done:
	lmw	r29, 8(r1)		/*restore r29 - r31 from stack */
	lwz	r0, +24(r1)		/* Get saved link register */
	addi	r1, r1, +20		/* Remove frame from stack */
	mtlr	r0			/* Restore link register */
	blr				/* Return to calling function */


/****************************************************************
    post_puts
    Accepts a null-terminated string pointed to by R3
    Outputs to the serial port until 0x00 is found.
    r3 returns the error code ( -1 if there is an error )
*****************************************************************/
post_puts:

	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -12(r1)		/* Save back chain and move SP */
	stw	r0, +16(r1)		/* Save link register */
	stw	r31, 8(r1)		/* save r31 - char pointer */

	addi 	r31, r3, 0              /* move pointer to R31 */
pputs_nxt:
	lbz	r3, 0(r31)		/* Get next character */
	addic.  r3, r3, 0		/* Check for zero */
	beq	pputs_term		/* bail out if zero */
	bl	post_putc		/* output the char */
	addic.	r3, r3, 0		/* check for error */
	bne	pputs_err
	addi 	r31, r31, 1		/* point to next char */
	b	pputs_nxt 		/* loop till term */
pputs_err:
	addi 	r3, 0, -1		/* set error code */
	b	pputs_end		/* were outa here */
pputs_term:
	addi 	r3, 0, 1		/* set success code */
	/* restore stack and return */
pputs_end:
	lwz	r31, 8(r1)		/* restore r27 - r31 from stack */
	lwz	r0, +16(r1)		/* Get saved link register */
	addi	r1, r1, +12		/* Remove frame from stack */
	mtlr	r0			/* Restore link register */
	blr				/* Return to calling function */


/********************************************************************
 *****	disp_hex
 *****	Routine to display a hex value from a register.
 *****	R3 is value to display
 *****	R4 is number of nibbles to display ie 2 for byte 8 for (long)word
 *****	Returns -1 in R3 if there is an error ( ie serial port hangs )
 *****	Returns 0 in R3 if no error
 *******************************************************************/
disp_hex:
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -16(r1)		/* Save back chain and move SP */
	stw	r0, +20(r1)		/* Save link register */
	stmw	r30, 8(r1)		/* save r30 - r31 on stack */
					/* r31 output char */
					/* r30 uart base address */
	addi 	r30, 0, 8               /* Go through 8 nibbles. */
	addi 	r31, r3, 0
pputh_nxt:
	rlwinm	r31, r31, 4, 0, 31	/* Rotate next nibble into position */
	andi. 	r3, r31, 0x0f		/* Get nibble. */
	addi 	r3, r3, 0x30		/* Add zero's ASCII code. */
	cmpwi	r3, 0x03a
	blt	pputh_out
	addi 	r3, r3, 0x07            /* 0x27 for lower case. */
pputh_out:
	cmpw 	r30, r4
	bgt	pputh_skip
	bl	post_putc
	addic. 	r3, r3, 0 		/* check for error */
	bne	pputh_err
pputh_skip:
	addic.	r30, r30, -1
	bne	pputh_nxt
	xor	r3, r3, r3		/* Clear error code */
	b	pputh_done
pputh_err:
	addi 	r3, 0, -1 		/* set error code */
pputh_done:
	/* restore stack and return */
	lmw	r30, 8(r1)		/*  restore r30 - r31 from stack */
	lwz	r0, +20(r1)		/* Get saved link register */
	addi	r1, r1, +16		/* Remove frame from stack */
	mtlr	r0			/* Restore link register */
	blr				/* Return to calling function */