--- /dev/null
+/* bigint_asm.S */
+/*
+ This file is part of the ARM-Crypto-Lib.
+ Copyright (C) 2006-2010 Daniel Otte (daniel.otte@rub.de)
+
+ 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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "avr-asm-macros.S"
+#include "bigint_adjust.S"
+#include "bigint_add_u.S"
+
+
+/******************************************************************************/
+/*
+void bigint_add_scale_u(bigint_t* dest, const bigint_t* a, uint16_t scale){
+ uint16_t i,j=0;
+ uint16_t t=0;
+ if(scale>dest->length_B)
+ memset(dest->wordv+dest->length_B, 0, scale-dest->length_B);
+ for(i=scale; i<a->length_B+scale; ++i,++j){
+ t = a->wordv[j] + t;
+ if(dest->length_B>i){
+ t += dest->wordv[i];
+ }
+ dest->wordv[i] = (uint8_t)t;
+ t>>=8;
+ }
+ while(t){
+ if(dest->length_B>i){
+ t = dest->wordv[i] + t;
+ }
+ dest->wordv[i] = (uint8_t)t;
+ t>>=8;
+ ++i;
+ }
+ if(dest->length_B < i){
+ dest->length_B = i;
+ }
+ bigint_adjust(dest);
+}
+*/
+
+DST_SIZE_0 = 22
+DST_SIZE_1 = 23
+SRC_SIZE_0 = 20
+SRC_SIZE_1 = 23
+SCALE_0 = 18
+SCALE_1 = 19
+DST_CTX_0 = 6
+DST_CTX_1 = 7
+SRC_CTX_0 = 8
+SRC_CTX_1 = 9
+TMP_0 = 10
+TMP_1 = 11
+
+.global bigint_add_scale_u
+#if 0
+bigint_add_scale_u:
+ push_range 6, 11
+ movw r30, r24 /* dest ptr */
+ movw r26, r22 /* src ptr */
+ movw r24, r20 /* scale */
+ movw DST_CTX_0, r30
+ movw SRC_CTX_0, r26
+ movw SCALE_0, r24
+ /* pad dst with zeros if scale > dst_length */
+ ld DST_SIZE_0, Z+
+ ld DST_SIZE_1, Z+
+ sub r24, DST_SIZE_0
+ sbc r25, DST_SIZE_1
+ ldd TMP_0, Z+1 /* load tmp with DST_WORDV */
+ ldd TMP_1, Z+2
+ movw r30, TMP_0
+ brmi 20f /* branch if DST_SIZE > scale */
+ add r30, DST_SIZE_0
+ adc r31, DST_SIZE_1
+10:
+ sbiw r24, 1
+ brmi 25f
+ st Z+, r1
+ rjmp 10b
+20:
+ add r30, r20 /* add scale to DST_WORDV */
+ adc r31, r21
+ /* add src to dest until one of the two ends */
+25:
+ ld SRC_SIZE_0, X+
+ ld SRC_SIZE_1, X+
+ adiw r26, 1
+ ld TMP_0, X+ /* load tmp with SRC_WORDV */
+ ld TMP_1, X
+ movw r26, TMP_0
+ movw r24, SRC_SIZE_0
+ add r24, SCALE_0
+ adc r25, SCALE_1
+ clt
+ cp r24, DST_SIZE_0
+ cpc r25, DST_SIZE_1
+ brlo 30f
+ set
+ movw r24, DST_SIZE_0
+30:
+ adiw r24, 0
+ breq 35f
+ inc r25
+ clc
+31:
+ ld TMP_0, X+
+ ld TMP_1, Z
+ adc TMP_1, TMP_0
+ st Z+, TMP_1
+ dec r24
+ brne 31b
+ dec r25
+ brne 31b
+35:
+ rol TMP_1
+ brts 40f
+ /* dst is longer than src+scale */
+ ror TMP_1
+38:
+ ld TMP_0, Z
+ adc TMP_0, r1
+ st Z+, TMP_0
+ brcs 38b
+ rjmp 90f
+40:
+ /* dst is shorter than src+scale */
+ movw r24, SRC_SIZE_0
+ sub r24, DST_SIZE_0
+ sbc r25, DST_SIZE_1
+ add r24, SCALE_0
+ adc r25, SCALE_1
+ adiw r24, 0
+ breq 90f
+ inc r25
+ ror TMP_1
+45:
+ ld TMP_0, X+
+ adc TMP_0, r1
+ st Z+, TMP_0
+ dec r24
+ brne 45b
+ dec r25
+ brne 45b
+
+90:
+ movw r24, DST_CTX_0
+ pop_range 6, 11
+ rjmp bigint_adjust
+
+#endif
+
+/******************************************************************************/
+/******************************************************************************/
+/******************************************************************************/
+
+DST_LEN_0 = 22
+DST_LEN_1 = 23
+SRC_LEN_0 = 20
+SRC_LEN_1 = 21
+SCALE_0 = 18
+SCALE_1 = 19
+DST_CTX_0 = 6
+DST_CTX_1 = 7
+SRC_CTX_0 = 8
+SRC_CTX_1 = 9
+TMP_0 = 10
+TMP_1 = 11
+
+bigint_add_scale_u:
+ push_range 6, 11
+ movw r30, r24 /* dest ptr */
+ movw r26, r22 /* src ptr */
+ movw r24, r20 /* scale */
+ movw DST_CTX_0, r30
+ movw SRC_CTX_0, r26
+ movw SCALE_0, r24
+
+ /* pad dest with zeros to length of SRC_LENGTH + scale */
+ ld SRC_LEN_0, X+
+ ld SRC_LEN_1, X+
+ adiw r26, 1
+ ld TMP_0, X+
+ ld TMP_1, X+
+ movw r26, TMP_0 /* move SRC_WORDV to X */
+ ldd DST_LEN_0, Z+0
+ ldd DST_LEN_1, Z+1
+ ldd TMP_0, Z+3
+ ldd TMP_1, Z+4
+ movw r30, TMP_0 /* move DEST_WORDV to Z */
+ movw TMP_0, SCALE_0
+ sub TMP_0, DST_LEN_0
+ sbc TMP_1, DST_LEN_1
+ movw r24, TMP_0
+ brmi 40f /* no padding needed since DST_LEN > scale */
+ add r30, DST_LEN_0 /* add DST_LEN to Z (DEST_WORDV)*/
+ adc r31, DST_LEN_1
+ /* pad and copy src in front of dest */
+10: /* padding loop */
+ sbiw r24, 1
+ brmi 11f
+ st Z+, r1
+ rjmp 10b
+11:
+ /* start of copy */
+
+ movw r24, SRC_LEN_0
+
+12: /* copy loop */
+ sbiw r24, 1
+ brmi 13f
+ ld TMP_0, X+
+ st Z+, TMP_0
+ rjmp 12b
+13:
+ movw TMP_0, SCALE_0
+ add TMP_0, SRC_LEN_0
+ adc TMP_1, SRC_LEN_1
+ movw r30, DST_CTX_0
+ std Z+0, TMP_0
+ std Z+1, TMP_1
+ movw r24, r30
+99:
+ pop_range 6, 11
+ rjmp bigint_adjust
+40:
+ /* TODO */
+ /* Z points at DST_WORDV */
+ /* X points at SRC_WORDV */
+ /* r24:r25 contains scale - DST_LEN (negativ) */
+ /* set T bit if DST_LEN > SCR_LEN + scale */
+ clt
+ add r30, SCALE_0
+ adc r31, SCALE_1
+ add TMP_0, SRC_LEN_0
+ adc TMP_1, SRC_LEN_1
+ brpl 41f
+ set
+ /* DST_LEN > SRC_LEN + scale && DST_LEN > scale */
+ /*
+ +-------+-------+ SRC + scale
+ +------+------------+ DST
+ */
+ movw r24, SRC_LEN_0
+ rjmp 44f
+41:
+ /* DST_LEN <= SRC_LEN + scale && DST_LEN > scale */
+ /*
+ +-------+-------+ SRC + scale
+ +------------+ DST
+ */
+ com r24 /* negate r24:r25 */
+ com r25
+ adiw r24, 1
+44:
+ clc
+45:
+ dec r24
+ brpl 46f
+ dec r25
+ brmi 50f
+46: ld TMP_0, X+
+ ld TMP_1, Z
+ adc TMP_0, TMP_1
+ st Z+, TMP_0
+ rjmp 45b
+
+50:
+ /* do the overhaning part */
+ rol r1
+ movw r24, r30
+ movw r30, DST_CTX_0
+ ldd TMP_0, Z+3
+ ldd TMP_1, Z+4
+ movw r30, TMP_0
+ add r30, DST_LEN_0
+ adc r31, DST_LEN_1
+ adiw r30, 1
+ st Z, r1
+ movw r30, r24
+ ror r1
+ brtc 60f
+51: brcc 53f
+52: ld TMP_0, Z
+ adc TMP_0, r1
+ st Z+, TMP_0
+ brcs 52b
+53:
+ /* TODO */
+ movw r24, r30
+ movw r30, DST_CTX_0
+ ldd TMP_0, Z+3
+ ldd TMP_1, Z+4
+ sub r24, TMP_0
+ sbc r25, TMP_1
+ std Z+0, r24
+ std Z+1, r25
+ movw r24, r30
+ rjmp 99b
+
+60: rol r1 /* backup carry */
+ movw r24, SRC_LEN_0
+ add r24, SCALE_0
+ adc r25, SCALE_1
+ sub r24, DST_LEN_0
+ sbc r25, DST_LEN_1
+ ror r1 /* restore carry */
+
+61: dec r24
+ brpl 62f
+ dec r25
+ brmi 63f
+62: ld TMP_0, X+
+ adc TMP_0, r1
+ st Z+, TMP_0
+ rjmp 61b
+63:
+ brcc 53b
+ ldi r24, 1
+ st Z+, r24
+ rjmp 53b
projects / avr-crypto-lib.git / blobdiff