diff options
Diffstat (limited to 'board/w7o/post1.S')
| -rw-r--r-- | board/w7o/post1.S | 745 |
1 files changed, 745 insertions, 0 deletions
diff --git a/board/w7o/post1.S b/board/w7o/post1.S new file mode 100644 index 0000000000..d510cca1f6 --- /dev/null +++ b/board/w7o/post1.S @@ -0,0 +1,745 @@ +/* + * (C) Copyright 2001 + * Bill Hunter, Wave 7 Optics, william.hunter@mediaone.net + * and + * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ +/* + * Description: + * Routine to exercise memory for the bringing up of our boards. + */ +#include <config.h> +#include <ppc4xx.h> + +#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */ + +#include <ppc_asm.tmpl> +#include <ppc_defs.h> + +#include <asm/cache.h> +#include <asm/mmu.h> + +#include <watchdog.h> + +#include "errors.h" + +#define _ASMLANGUAGE + + .globl test_sdram + .globl test_led + .globl log_stat + .globl log_warn + .globl log_err + .globl temp_uart_init + .globl post_puts + .globl disp_hex + +/***************************************************** +******* Text Strings for low level printing ****** +******* In section got2 ******* +*****************************************************/ + +/* + * Define the text strings for errors and warnings. + * Switch to .data section. + */ + .section ".data" +err_str: .asciz "*** POST ERROR = " +warn_str: .asciz "*** POST WARNING = " +end_str: .asciz "\r\n" + +/* + * Enter the labels in Global Entry Table (GOT). + * Switch to .got2 section. + */ + START_GOT + GOT_ENTRY(err_str) + GOT_ENTRY(warn_str) + GOT_ENTRY(end_str) + END_GOT + +/* + * Switch back to .text section. + */ + .text + +/**************************************** + **************************************** + ******** LED register test ******** + **************************************** + ***************************************/ +test_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 */ + + WATCHDOG_RESET /* Reset the watchdog */ + + addi r3, 0, ERR_FF /* first test value is ffff */ + addi r4, r3, 0 /* save copy of pattern */ + bl set_led /* store first test value */ + bl get_led /* read it back */ + xor. r4, r4, r3 /* compare to original */ +#if defined(CONFIG_W7OLMC) + andi. r4, r4, 0x00ff /* lmc has 8 bits */ +#else + andi. r4, r4, 0xffff /* lmg has 16 bits */ +#endif + beq LED2 /* next test */ + addi r3, 0, ERR_LED /* error code = 1 */ + bl log_err /* display error and halt */ +LED2: addi r3, 0, ERR_00 /* 2nd test value is 0000 */ + addi r4, r3, 0 /* save copy of pattern */ + bl set_led /* store first test value */ + bl get_led /* read it back */ + xor. r4, r4, r3 /* compare to original */ +#if defined(CONFIG_W7OLMC) + andi. r4, r4, 0x00ff /* lmc has 8 bits */ +#else + andi. r4, r4, 0xffff /* lmg has 16 bits */ +#endif + beq LED3 /* next test */ + addi r3, 0, ERR_LED /* error code = 1 */ + bl log_err /* display error and halt */ + +LED3: /* 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 */ + +/**************************************** + **************************************** + ******** SDRAM TESTS ******** + **************************************** + ***************************************/ +test_sdram: + /* called with mem size in r3 */ + /* 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 */ + /* r30 is log2(mem size) */ + /* r31 is mem size */ + + /* take log2 of total mem size */ + addi r31, r3, 0 /* save total mem size */ + addi r30, 0, 0 /* clear r30 */ +l2_loop: + srwi. r31, r31, 1 /* shift right 1 */ + addi r30, r30, 1 /* count shifts */ + bne l2_loop /* loop till done */ + addi r30, r30, -1 /* correct for over count */ + addi r31, r3, 0 /* save original size */ + + /* now kick the dog and test the mem */ + WATCHDOG_RESET /* Reset the watchdog */ + bl Data_Buster /* test crossed/shorted data lines */ + addi r3, r30, 0 /* get log2(memsize) */ + addi r4, r31, 0 /* get memsize */ + bl Ghost_Buster /* test crossed/shorted addr lines */ + addi r3, r31, 0 /* get mem size */ + bl Bit_Buster /* check for bad internal bits */ + + /* restore stack and return */ + lmw r30, +8(r1) /* Restore r30, r31 */ + lwz r0, +20(r1) /* Get saved link register */ + mtlr r0 /* Restore link register */ + addi r1, r1, +16 /* Remove frame from stack */ + blr /* Return to calling function */ + + +/**************************************** + ******** sdram data bus test ******** + ***************************************/ +Data_Buster: + /* save the return info on stack */ + mflr r0 /* Get link register */ + stwu r1, -24(r1) /* Save back chain and move SP */ + stw r0, +28(r1) /* Save link register */ + stmw r28, 8(r1) /* save r28 - r31 on stack */ + /* r31 i/o register */ + /* r30 sdram base address */ + /* r29 5555 syndrom */ + /* r28 aaaa syndrom */ + + /* set up led register for this test */ + addi r3, 0, ERR_RAMG /* set led code to 1 */ + bl log_stat /* store test value */ + /* now test the dram data bus */ + xor r30, r30, r30 /* load r30 with base addr of sdram */ + addis r31, 0, 0x5555 /* load r31 with test value */ + ori r31, r31, 0x5555 + stw r31,0(r30) /* sto the value */ + lwz r29,0(r30) /* read it back */ + xor r29,r31,r29 /* compare it to original */ + addis r31, 0, 0xaaaa /* load r31 with test value */ + ori r31, r31, 0xaaaa + stw r31,0(r30) /* sto the value */ + lwz r28,0(r30) /* read it back */ + xor r28,r31,r28 /* compare it to original */ + or r3,r28,r29 /* or together both error terms */ + /* + * Now that we have the error bits, + * we have to decide which part they are in. + */ + bl get_idx /* r5 is now index to error */ + addi r3, r3, ERR_RAMG + cmpwi r3, ERR_RAMG /* check for errors */ + beq db_done /* skip if no errors */ + bl log_err /* log the error */ + +db_done: + lmw r28, 8(r1) /* restore r28 - r31 from stack */ + lwz r0, +28(r1) /* Get saved link register */ + addi r1, r1, +24 /* Remove frame from stack */ + mtlr r0 /* Restore link register */ + blr /* Return to calling function */ + + +/**************************************************** + ******** test for address ghosting in dram ******** + ***************************************************/ + +Ghost_Buster: + /* save the return info on stack */ + mflr r0 /* Get link register */ + stwu r1, -36(r1) /* Save back chain and move SP */ + stw r0, +40(r1) /* Save link register */ + stmw r25, 8(r1) /* save r25 - r31 on stack */ + /* r31 = scratch register */ + /* r30 is main referance loop counter, + 0 to 23 */ + /* r29 is ghost loop count, 0 to 22 */ + /* r28 is referance address */ + /* r27 is ghost address */ + /* r26 is log2 (mem size) = + number of byte addr bits */ + /* r25 is mem size */ + + /* save the log2(mem size) and mem size */ + addi r26, r3, 0 /* r26 is number of byte addr bits */ + addi r25, r4, 0 /* r25 is mem size in bytes */ + + /* set the leds for address ghost test */ + addi r3, 0, ERR_ADDG + bl set_led + + /* first fill memory with zeros */ + srwi r31, r25, 2 /* convert bytes to longs */ + mtctr r31 /* setup byte counter */ + addi r28, 0, 0 /* start at address at 0 */ + addi r31, 0, 0 /* data value = 0 */ +clr_loop: + stw r31, 0(r28) /* Store zero value */ + addi r28, r28, 4 /* Increment to next word */ + andi. r27, r28, 0xffff /* check for 2^16 loops */ + bne clr_skip /* if not there, then skip */ + WATCHDOG_RESET /* kick the dog every now and then */ +clr_skip: + bdnz clr_loop /* Round and round... */ + + /* now do main test */ + addi r30, 0, 0 /* start referance counter at 0 */ +outside: + /* + * Calculate the referance address + * the referance address is calculated by setting the (r30-1) + * bit of the base address + * when r30=0, the referance address is the base address. + * thus the sequence 0,1,2,4,8,..,2^(n-1) + * setting the bit is done with the following shift functions. + */ + WATCHDOG_RESET /* Reset the watchdog */ + + addi r31, 0, 1 /* r31 = 1 */ + slw r28, r31, r30 /* set bit coresponding to loop cnt */ + srwi r28, r28, 1 /* then shift it right one so */ + /* we start at location 0 */ + /* fill referance address with Fs */ + addi r31, 0, 0x00ff /* r31 = one byte of set bits */ + stb r31,0(r28) /* save ff in referance address */ + + /* ghost (inner) loop, now check all posible ghosted addresses */ + addi r29, 0, 0 /* start ghosted loop counter at 0 */ +inside: + /* + * Calculate the ghost address by flipping one + * bit of referance address. This gives the + * sequence 1,2,4,8,...,2^(n-1) + */ + addi r31, 0, 1 /* r31 = 1 */ + slw r27, r31, r29 /* set bit coresponding to loop cnt */ + xor r27, r28, r27 /* ghost address = ref addr with + bit flipped*/ + + /* now check for ghosting */ + lbz r31,0(r27) /* get content of ghost addr */ + cmpwi r31, 0 /* compare read value to 0 */ + bne Casper /* we found a ghost! */ + + /* now close ghost ( inner ) loop */ + addi r29, r29, 1 /* increment inner loop counter */ + cmpw r29, r26 /* check for last inner loop */ + blt inside /* do more inner loops */ + + /* now close referance ( outer ) loop */ + addi r31, 0, 0 /* r31 = zero */ + stb r31, 0(28) /* zero out the altered address loc. */ + /* + * Increment and check for end, count is zero based. + * With the ble, this gives us one more loops than + * address bits for sequence 0,1,2,4,8,...2^(n-1) + */ + addi r30, r30, 1 /* increment outer loop counter */ + cmpw r30, r26 /* check for last inner loop */ + ble outside /* do more outer loops */ + + /* were done, lets go home */ + b gb_done +Casper: /* we found a ghost !! */ + addi r3, 0, ERR_ADDF /* get indexed error message */ + bl log_err /* log error led error code */ +gb_done: /* pack your bags, and go home */ + lmw r25, 8(r1) /* restore r25 - r31 from stack */ + lwz r0, +40(r1) /* Get saved link register */ + addi r1, r1, +36 /* Remove frame from stack */ + mtlr r0 /* Restore link register */ + blr /* Return to calling function */ + +/**************************************************** + ******** SDRAM data fill tests ********** + ***************************************************/ +Bit_Buster: + /* called with mem size in r3 */ + /* 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 r4, +8(r1) /* save R4 */ + stw r5, +12(r1) /* save r5 */ + + addis r5, r3, 0 /* save mem size */ + + /* Test 55555555 */ + addi r3, 0, ERR_R55G /* set up error code in case we fail */ + bl log_stat /* store test value */ + addis r4, 0, 0x5555 + ori r4, r4, 0x5555 + bl fill_test + + /* Test aaaaaaaa */ + addi r3, 0, ERR_RAAG /* set up error code in case we fail */ + bl log_stat /* store test value */ + addis r4, 0, 0xAAAA + ori r4, r4, 0xAAAA + bl fill_test + + /* Test 00000000 */ + addi r3, 0, ERR_R00G /* set up error code in case we fail */ + bl log_stat /* store test value */ + addis r4, 0, 0 + ori r4, r4, 0 + bl fill_test + + /* restore stack and return */ + lwz r5, +12(r1) /* restore r4 */ + lwz r4, +8(r1) /* restore r4 */ + 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 */ + + + +/**************************************************** + ******** 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 */ + |
