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Diffstat (limited to 'contrib/loaders/flash/pic32mx.s')
-rw-r--r-- | contrib/loaders/flash/pic32mx.s | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/contrib/loaders/flash/pic32mx.s b/contrib/loaders/flash/pic32mx.s new file mode 100644 index 00000000..b26ff611 --- /dev/null +++ b/contrib/loaders/flash/pic32mx.s @@ -0,0 +1,131 @@ +/*************************************************************************** + * Copyright (C) 2010 by Spencer Oliver * + * spen@spen-soft.co.uk * + * * + * 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. * + ***************************************************************************/ + + .text + .set noreorder + .set noat + +/* params: + * $a0 src adr - ram + result + * $a1 dest adr - flash + * $a2 count (32bit words) + * vars + * + * temps: + * $t0, $t1, $t2, $t3, $t4, $t5 + * $s0, $s1, $s3, $s4, $s5 + */ + + .type main, @function + .global main + +.ent main +main: + /* setup constants */ + lui $t0, 0xaa99 + ori $t0, 0x6655 /* NVMKEY1 */ + lui $t1, 0x5566 + ori $t1, 0x99AA /* NVMKEY2 */ + lui $t2, 0xBF80 + ori $t2, 0xF400 /* NVMCON */ + ori $t3, $zero, 0x4003 /* NVMCON row write cmd */ + ori $t4, $zero, 0x8000 /* NVMCON start cmd */ + +write_row: + /* can we perform a row write: 128 32bit words */ + sltiu $s3, $a2, 128 + bne $s3, $zero, write_word + ori $t5, $zero, 0x4000 /* NVMCON clear cmd */ + + /* perform row write 512 bytes */ + sw $a1, 32($t2) /* set NVMADDR with dest addr - real addr */ + sw $a0, 64($t2) /* set NVMSRCADDR with src addr - real addr */ + + bal progflash + addiu $a0, $a0, 512 + addiu $a1, $a1, 512 + beq $zero, $zero, write_row + addiu $a2, $a2, -128 + +write_word: + /* write 32bit words */ + lui $s5, 0xa000 + ori $s5, 0x0000 + or $a0, $a0, $s5 /* convert to virtual addr */ + + beq $zero, $zero, next_word + ori $t3, $zero, 0x4001 /* NVMCON word write cmd */ + +prog_word: + lw $s4, 0($a0) /* load data - from virtual addr */ + sw $s4, 48($t2) /* set NVMDATA with data */ + sw $a1, 32($t2) /* set NVMADDR with dest addr - real addr */ + + bal progflash + addiu $a0, $a0, 4 + addiu $a1, $a1, 4 + addiu $a2, $a2, -1 +next_word: + bne $a2, $zero, prog_word + nop + +done: + beq $zero, $zero, exit + addiu $a0, $zero, 0 + +error: + /* save result to $a0 */ + addiu $a0, $s1, 0 + +exit: + sdbbp +.end main + + .type progflash, @function + .global progflash + +.ent progflash +progflash: + sw $t3, 0($t2) /* set NVMWREN */ + sw $t0, 16($t2) /* write NVMKEY1 */ + sw $t1, 16($t2) /* write NVMKEY2 */ + sw $t4, 8($t2) /* start operation */ + +waitflash: + lw $s0, 0($t2) + and $s0, $s0, $t4 + bne $s0, $zero, waitflash + nop + + /* following is to comply with errata #34 + * 500ns delay required */ + nop + nop + nop + nop + /* check for errors */ + lw $s1, 0($t2) + andi $s1, $zero, 0x3000 + bne $s1, $zero, error + sw $t5, 4($t2) /* clear NVMWREN */ + jr $ra + nop + +.end progflash |