| /* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */ |
| |
| #ifndef _UECC_ASM_AVR_H_ |
| #define _UECC_ASM_AVR_H_ |
| |
| #if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1) |
| #define uECC_MIN_WORDS 32 |
| #endif |
| #if uECC_SUPPORTS_secp224r1 |
| #undef uECC_MIN_WORDS |
| #define uECC_MIN_WORDS 28 |
| #endif |
| #if uECC_SUPPORTS_secp192r1 |
| #undef uECC_MIN_WORDS |
| #define uECC_MIN_WORDS 24 |
| #endif |
| #if uECC_SUPPORTS_secp160r1 |
| #undef uECC_MIN_WORDS |
| #define uECC_MIN_WORDS 20 |
| #endif |
| |
| #if __AVR_HAVE_EIJMP_EICALL__ |
| #define IJMP "eijmp \n\t" |
| #else |
| #define IJMP "ijmp \n\t" |
| #endif |
| |
| #if (uECC_OPTIMIZATION_LEVEL >= 2) |
| |
| uECC_VLI_API void uECC_vli_clear(uECC_word_t *vli, wordcount_t num_words) { |
| volatile uECC_word_t *v = vli; |
| __asm__ volatile ( |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| "ldi r30, pm_lo8(1f) \n\t" |
| "ldi r31, pm_hi8(1f) \n\t" |
| "sub r30, %[num] \n\t" |
| "sbc r31, __zero_reg__ \n\t" |
| IJMP |
| #endif |
| |
| REPEAT(uECC_MAX_WORDS, "st x+, __zero_reg__ \n\t") |
| "1: \n\t" |
| : "+x" (v) |
| : [num] "r" (num_words) |
| : |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| "r30", "r31", "cc" |
| #endif |
| ); |
| } |
| #define asm_clear 1 |
| |
| uECC_VLI_API void uECC_vli_set(uECC_word_t *dest, const uECC_word_t *src, wordcount_t num_words) { |
| volatile uECC_word_t *d = dest; |
| __asm__ volatile ( |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| "ldi r30, pm_lo8(1f) \n\t" |
| "ldi r31, pm_hi8(1f) \n\t" |
| "sub r30, %[num] \n\t" |
| "sbc r31, __zero_reg__ \n\t" |
| IJMP |
| #endif |
| |
| REPEAT(uECC_MAX_WORDS, |
| "ld r0, y+ \n\t" |
| "st x+, r0 \n\t") |
| "1: \n\t" |
| : "+x" (d), "+y" (src) |
| : [num] "r" ((uint8_t)(num_words * 2)) |
| : "r0", |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| "r30", "r31", "cc" |
| #endif |
| ); |
| } |
| #define asm_set 1 |
| |
| uECC_VLI_API void uECC_vli_rshift1(uECC_word_t *vli, wordcount_t num_words) { |
| volatile uECC_word_t *v = vli; |
| __asm__ volatile ( |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| "ldi r30, pm_lo8(1f) \n\t" |
| "ldi r31, pm_hi8(1f) \n\t" |
| "sub r30, %[jump] \n\t" |
| "sbc r31, __zero_reg__ \n\t" |
| #endif |
| |
| "add r26, %[num] \n\t" |
| "adc r27, __zero_reg__ \n\t" |
| "ld r0, -x \n\t" |
| "lsr r0 \n\t" |
| "st x, r0 \n\t" |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| IJMP |
| #endif |
| |
| REPEAT(DEC(uECC_MAX_WORDS), |
| "ld r0, -x \n\t" |
| "ror r0 \n\t" |
| "st x, r0 \n\t") |
| "1: \n\t" |
| : "+x" (v) |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| : [num] "r" (num_words), [jump] "r" ((uint8_t)(3 * (num_words - 1))) |
| : "r0", "r30", "r31", "cc" |
| #else |
| : [num] "r" (num_words) |
| : "r0", "cc" |
| #endif |
| ); |
| } |
| #define asm_rshift1 1 |
| |
| #define ADD_RJPM_TABLE(N) \ |
| "movw r30, %A[result] \n\t" \ |
| "rjmp add_%=_" #N " \n\t" |
| |
| #define ADD_RJPM_DEST(N) \ |
| "add_%=_" #N ":" \ |
| "ld %[clb], x+ \n\t" \ |
| "ld %[rb], y+ \n\t" \ |
| "adc %[clb], %[rb] \n\t" \ |
| "st z+, %[clb] \n\t" |
| |
| uECC_VLI_API uECC_word_t uECC_vli_add(uECC_word_t *result, |
| const uECC_word_t *left, |
| const uECC_word_t *right, |
| wordcount_t num_words) { |
| volatile uECC_word_t *r = result; |
| uint8_t carry; |
| uint8_t right_byte; |
| |
| __asm__ volatile ( |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| "ldi r30, pm_lo8(add_%=_" STR(uECC_MAX_WORDS) ") \n\t" |
| "ldi r31, pm_hi8(add_%=_" STR(uECC_MAX_WORDS) ") \n\t" |
| "sub r30, %[num] \n\t" |
| "sbc r31, __zero_reg__ \n\t" |
| #endif |
| |
| "clc \n\t" |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| IJMP |
| REPEATM(uECC_MAX_WORDS, ADD_RJPM_TABLE) |
| #endif |
| |
| REPEATM(uECC_MAX_WORDS, ADD_RJPM_DEST) |
| |
| "mov %[clb], __zero_reg__ \n\t" |
| "adc %[clb], %[clb] \n\t" /* Store carry bit. */ |
| |
| : "+x" (left), "+y" (right), |
| [clb] "=&r" (carry), [rb] "=&r" (right_byte) |
| : [result] "r" (r), [num] "r" ((uint8_t)(num_words * 2)) |
| : "r30", "r31", "cc" |
| ); |
| return carry; |
| } |
| #define asm_add 1 |
| |
| #define SUB_RJPM_TABLE(N) \ |
| "movw r30, %A[result] \n\t" \ |
| "rjmp sub_%=_" #N " \n\t" |
| |
| #define SUB_RJPM_DEST(N) \ |
| "sub_%=_" #N ":" \ |
| "ld %[clb], x+ \n\t" \ |
| "ld %[rb], y+ \n\t" \ |
| "sbc %[clb], %[rb] \n\t" \ |
| "st z+, %[clb] \n\t" |
| |
| uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result, |
| const uECC_word_t *left, |
| const uECC_word_t *right, |
| wordcount_t num_words) { |
| volatile uECC_word_t *r = result; |
| uint8_t carry; |
| uint8_t right_byte; |
| |
| __asm__ volatile ( |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| "ldi r30, pm_lo8(sub_%=_" STR(uECC_MAX_WORDS) ") \n\t" |
| "ldi r31, pm_hi8(sub_%=_" STR(uECC_MAX_WORDS) ") \n\t" |
| "sub r30, %[num] \n\t" |
| "sbc r31, __zero_reg__ \n\t" |
| #endif |
| |
| "clc \n\t" |
| #if (uECC_MAX_WORDS != uECC_MIN_WORDS) |
| IJMP |
| REPEATM(uECC_MAX_WORDS, SUB_RJPM_TABLE) |
| #endif |
| |
| REPEATM(uECC_MAX_WORDS, SUB_RJPM_DEST) |
| |
| "mov %[clb], __zero_reg__ \n\t" |
| "adc %[clb], %[clb] \n\t" /* Store carry bit. */ |
| |
| : "+x" (left), "+y" (right), |
| [clb] "=&r" (carry), [rb] "=&r" (right_byte) |
| : [result] "r" (r), [num] "r" ((uint8_t)(num_words * 2)) |
| : "r30", "r31", "cc" |
| ); |
| return carry; |
| } |
| #define asm_sub 1 |
| |
| #if (uECC_OPTIMIZATION_LEVEL >= 3) |
| |
| #include "asm_avr_mult_square.inc" |
| |
| __attribute((noinline)) |
| uECC_VLI_API void uECC_vli_mult(uECC_word_t *result, |
| const uECC_word_t *left, |
| const uECC_word_t *right, |
| wordcount_t num_words) { |
| /* num_words should already be in r18. */ |
| register wordcount_t r18 __asm__("r18") = num_words; |
| |
| __asm__ volatile ( |
| "push r18 \n\t" |
| #if (uECC_MIN_WORDS == 20) |
| FAST_MULT_ASM_20 |
| "pop r18 \n\t" |
| #if (uECC_MAX_WORDS > 20) |
| FAST_MULT_ASM_20_TO_24 |
| #endif |
| #if (uECC_MAX_WORDS > 24) |
| FAST_MULT_ASM_24_TO_28 |
| #endif |
| #if (uECC_MAX_WORDS > 28) |
| FAST_MULT_ASM_28_TO_32 |
| #endif |
| #elif (uECC_MIN_WORDS == 24) |
| FAST_MULT_ASM_24 |
| "pop r18 \n\t" |
| #if (uECC_MAX_WORDS > 24) |
| FAST_MULT_ASM_24_TO_28 |
| #endif |
| #if (uECC_MAX_WORDS > 28) |
| FAST_MULT_ASM_28_TO_32 |
| #endif |
| #elif (uECC_MIN_WORDS == 28) |
| FAST_MULT_ASM_28 |
| "pop r18 \n\t" |
| #if (uECC_MAX_WORDS > 28) |
| FAST_MULT_ASM_28_TO_32 |
| #endif |
| #elif (uECC_MIN_WORDS == 32) |
| FAST_MULT_ASM_32 |
| "pop r18 \n\t" |
| #endif |
| "2: \n\t" |
| "eor r1, r1 \n\t" |
| : "+x" (left), "+y" (right), "+z" (result) |
| : "r" (r18) |
| : "r0", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", |
| "r11", "r12", "r13", "r14", "r15", "r16", "r17", "r19", "r20", |
| "r21", "r22", "r23", "r24", "r25", "cc" |
| ); |
| } |
| #define asm_mult 1 |
| |
| #if uECC_SQUARE_FUNC |
| __attribute((noinline)) |
| uECC_VLI_API void uECC_vli_square(uECC_word_t *result, |
| const uECC_word_t *left, |
| wordcount_t num_words) { |
| /* num_words should already be in r20. */ |
| register wordcount_t r20 __asm__("r20") = num_words; |
| |
| __asm__ volatile ( |
| "push r20 \n\t" |
| #if (uECC_MIN_WORDS == 20) |
| FAST_SQUARE_ASM_20 |
| "pop r20 \n\t" |
| #if (uECC_MAX_WORDS > 20) |
| FAST_SQUARE_ASM_20_TO_24 |
| #endif |
| #if (uECC_MAX_WORDS > 24) |
| FAST_SQUARE_ASM_24_TO_28 |
| #endif |
| #if (uECC_MAX_WORDS > 28) |
| FAST_SQUARE_ASM_28_TO_32 |
| #endif |
| #elif (uECC_MIN_WORDS == 24) |
| FAST_SQUARE_ASM_24 |
| "pop r20 \n\t" |
| #if (uECC_MAX_WORDS > 24) |
| FAST_SQUARE_ASM_24_TO_28 |
| #endif |
| #if (uECC_MAX_WORDS > 28) |
| FAST_SQUARE_ASM_28_TO_32 |
| #endif |
| #elif (uECC_MIN_WORDS == 28) |
| FAST_SQUARE_ASM_28 |
| "pop r20 \n\t" |
| #if (uECC_MAX_WORDS > 28) |
| FAST_SQUARE_ASM_28_TO_32 |
| #endif |
| #elif (uECC_MIN_WORDS == 32) |
| FAST_SQUARE_ASM_32 |
| "pop r20 \n\t" |
| #endif |
| "2: \n\t" |
| "eor r1, r1 \n\t" |
| : "+x" (left), "+z" (result) |
| : "r" (r20) |
| : "r0", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", |
| "r11", "r12", "r13", "r14", "r15", "r16", "r17", "r18", "r19", |
| "r21", "r22", "r23", "r24", "r25", "r28", "r29", "cc" |
| ); |
| } |
| #define asm_square 1 |
| #endif /* uECC_SQUARE_FUNC */ |
| |
| #endif /* (uECC_OPTIMIZATION_LEVEL >= 3) */ |
| |
| #if uECC_SUPPORTS_secp160r1 |
| static const struct uECC_Curve_t curve_secp160r1; |
| static void vli_mmod_fast_secp160r1(uECC_word_t *result, uECC_word_t *product) { |
| uint8_t carry = 0; |
| __asm__ volatile ( |
| "in r30, __SP_L__ \n\t" |
| "in r31, __SP_H__ \n\t" |
| "sbiw r30, 24 \n\t" |
| "in r0, __SREG__ \n\t" |
| "cli \n\t" |
| "out __SP_H__, r31 \n\t" |
| "out __SREG__, r0 \n\t" |
| "out __SP_L__, r30 \n\t" |
| |
| "adiw r30, 25 \n\t" /* we are shifting by 31 bits, so shift over 4 bytes |
| (+ 1 since z initially points below the stack) */ |
| "adiw r26, 40 \n\t" /* end of product */ |
| "ld r18, -x \n\t" /* Load word. */ |
| "lsr r18 \n\t" /* Shift. */ |
| "st -z, r18 \n\t" /* Store the first result word. */ |
| |
| /* Now we just do the remaining words with the carry bit (using ROR) */ |
| REPEAT(19, |
| "ld r18, -x \n\t" |
| "ror r18 \n\t" |
| "st -z, r18 \n\t") |
| |
| "eor r18, r18 \n\t" /* r18 = 0 */ |
| "ror r18 \n\t" /* get last bit */ |
| "st -z, r18 \n\t" /* store it */ |
| |
| "sbiw r30, 3 \n\t" /* move z back to point at tmp */ |
| /* now we add right */ |
| "ld r18, x+ \n\t" |
| "st z+, r18 \n\t" /* the first 3 bytes do not need to be added */ |
| "ld r18, x+ \n\t" |
| "st z+, r18 \n\t" |
| "ld r18, x+ \n\t" |
| "st z+, r18 \n\t" |
| |
| "ld r18, x+ \n\t" |
| "ld r19, z \n\t" |
| "add r18, r19 \n\t" |
| "st z+, r18 \n\t" |
| |
| /* Now we just do the remaining words with the carry bit (using ADC) */ |
| REPEAT(16, |
| "ld r18, x+ \n\t" |
| "ld r19, z \n\t" |
| "adc r18, r19 \n\t" |
| "st z+, r18 \n\t") |
| |
| /* Propagate over the remaining bytes of result */ |
| "ld r18, z \n\t" |
| "adc r18, r1 \n\t" |
| "st z+, r18 \n\t" |
| |
| "ld r18, z \n\t" |
| "adc r18, r1 \n\t" |
| "st z+, r18 \n\t" |
| |
| "ld r18, z \n\t" |
| "adc r18, r1 \n\t" |
| "st z+, r18 \n\t" |
| |
| "ld r18, z \n\t" |
| "adc r18, r1 \n\t" |
| "st z+, r18 \n\t" |
| |
| "sbiw r30, 24 \n\t" /* move z back to point at tmp */ |
| "sbiw r26, 40 \n\t" /* move x back to point at product */ |
| |
| /* add low bytes of tmp to product, storing in result */ |
| "ld r18, z+ \n\t" |
| "ld r19, x+ \n\t" |
| "add r18, r19 \n\t" |
| "st y+, r18 \n\t" |
| REPEAT(19, |
| "ld r18, z+ \n\t" |
| "ld r19, x+ \n\t" |
| "adc r18, r19 \n\t" |
| "st y+, r18 \n\t") |
| "adc %[carry], __zero_reg__ \n\t" /* Store carry bit (carry flag is cleared). */ |
| /* at this point x is at the end of product, y is at the end of result, |
| z is 20 bytes into tmp */ |
| "sbiw r28, 20 \n\t" /* move y back to point at result */ |
| "adiw r30, 4 \n\t" /* move z to point to the end of tmp */ |
| |
| /* do omega_mult again with the 4 relevant bytes */ |
| /* z points to the end of tmp, x points to the end of product */ |
| "ld r18, -z \n\t" /* Load word. */ |
| "lsr r18 \n\t" /* Shift. */ |
| "st -x, r18 \n\t" /* Store the first result word. */ |
| |
| "ld r18, -z \n\t" |
| "ror r18 \n\t" |
| "st -x, r18 \n\t" |
| "ld r18, -z \n\t" |
| "ror r18 \n\t" |
| "st -x, r18 \n\t" |
| "ld r18, -z \n\t" |
| "ror r18 \n\t" |
| "st -x, r18 \n\t" |
| |
| "eor r18, r18 \n\t" /* r18 = 0 */ |
| "ror r18 \n\t" /* get last bit */ |
| "st -x, r18 \n\t" /* store it */ |
| |
| "sbiw r26, 3 \n\t" /* move x back to point at beginning */ |
| /* now we add a copy of the 4 bytes */ |
| "ld r18, z+ \n\t" |
| "st x+, r18 \n\t" /* the first 3 bytes do not need to be added */ |
| "ld r18, z+ \n\t" |
| "st x+, r18 \n\t" |
| "ld r18, z+ \n\t" |
| "st x+, r18 \n\t" |
| |
| "ld r18, z+ \n\t" |
| "ld r19, x \n\t" |
| "add r18, r19 \n\t" |
| "st x+, r18 \n\t" |
| |
| /* Propagate over the remaining bytes */ |
| "ld r18, x \n\t" |
| "adc r18, r1 \n\t" |
| "st x+, r18 \n\t" |
| |
| "ld r18, x \n\t" |
| "adc r18, r1 \n\t" |
| "st x+, r18 \n\t" |
| |
| "ld r18, x \n\t" |
| "adc r18, r1 \n\t" |
| "st x+, r18 \n\t" |
| |
| "ld r18, x \n\t" |
| "adc r18, r1 \n\t" |
| "st x+, r18 \n\t" |
| |
| /* now z points to the end of tmp, x points to the end of product |
| (y still points at result) */ |
| "sbiw r26, 8 \n\t" /* move x back to point at beginning of actual data */ |
| /* add into result */ |
| "ld r18, x+ \n\t" |
| "ld r19, y \n\t" |
| "add r18, r19 \n\t" |
| "st y+, r18 \n\t" |
| REPEAT(7, |
| "ld r18, x+ \n\t" |
| "ld r19, y \n\t" |
| "adc r18, r19 \n\t" |
| "st y+, r18 \n\t") |
| |
| /* Done adding, now propagate carry bit */ |
| REPEAT(12, |
| "ld r18, y \n\t" |
| "adc r18, __zero_reg__ \n\t" |
| "st y+, r18 \n\t") |
| |
| "adc %[carry], __zero_reg__ \n\t" /* Store carry bit (carry flag is cleared). */ |
| "sbiw r28, 20 \n\t" /* move y back to point at result */ |
| |
| "sbiw r30, 1 \n\t" /* fix stack pointer */ |
| "in r0, __SREG__ \n\t" |
| "cli \n\t" |
| "out __SP_H__, r31 \n\t" |
| "out __SREG__, r0 \n\t" |
| "out __SP_L__, r30 \n\t" |
| |
| : "+x" (product), [carry] "+r" (carry) |
| : "y" (result) |
| : "r0", "r18", "r19", "r30", "r31", "cc" |
| ); |
| |
| if (carry > 0) { |
| --carry; |
| uECC_vli_sub(result, result, curve_secp160r1.p, 20); |
| } |
| if (carry > 0) { |
| uECC_vli_sub(result, result, curve_secp160r1.p, 20); |
| } |
| if (uECC_vli_cmp_unsafe(result, curve_secp160r1.p, 20) > 0) { |
| uECC_vli_sub(result, result, curve_secp160r1.p, 20); |
| } |
| } |
| #define asm_mmod_fast_secp160r1 1 |
| #endif /* uECC_SUPPORTS_secp160r1 */ |
| |
| #if uECC_SUPPORTS_secp256k1 |
| static const struct uECC_Curve_t curve_secp256k1; |
| static void vli_mmod_fast_secp256k1(uECC_word_t *result, uECC_word_t *product) { |
| uint8_t carry = 0; |
| __asm__ volatile ( |
| "in r30, __SP_L__ \n\t" |
| "in r31, __SP_H__ \n\t" |
| "sbiw r30, 37 \n\t" |
| "in r0, __SREG__ \n\t" |
| "cli \n\t" |
| "out __SP_H__, r31 \n\t" |
| "out __SREG__, r0 \n\t" |
| "out __SP_L__, r30 \n\t" |
| |
| "adiw r30, 1 \n\t" /* add 1 since z initially points below the stack */ |
| "adiw r26, 32 \n\t" /* product + uECC_WORDS */ |
| "ldi r25, 0x03 \n\t" |
| "ldi r24, 0xD1 \n\t" |
| "ld r18, x+ \n\t" |
| "ld r19, x+ \n\t" |
| "ld r20, x+ \n\t" |
| "ld r21, x+ \n\t" |
| |
| "mul r24, r18 \n\t" |
| "st z+, r0 \n\t" |
| "mov r22, r1 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "mul r24, r19 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" /* can't overflow */ |
| "mul r25, r18 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" /* can't overflow */ |
| "st z+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| "mul r24, r20 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "mul r25, r19 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st z+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "mul r24, r21 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "mul r25, r20 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "st z+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| /* now we start adding the 2^32 part as well */ |
| "add r23, r18 \n\t" // 28 |
| "adc r22, r22 \n\t" |
| "ld r18, x+ \n\t" |
| "mul r24, r18 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "mul r25, r21 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st z+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "add r22, r19 \n\t" // 27 |
| "adc r23, r23 \n\t" |
| "ld r19, x+ \n\t" |
| "mul r24, r19 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "mul r25, r18 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "st z+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| REPEAT(6, // 26 - 3 |
| "add r23, r20 \n\t" |
| "adc r22, r22 \n\t" |
| "ld r20, x+ \n\t" |
| "mul r24, r20 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "mul r25, r19 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st z+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "add r22, r21 \n\t" |
| "adc r23, r23 \n\t" |
| "ld r21, x+ \n\t" |
| "mul r24, r21 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "mul r25, r20 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "st z+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| "add r23, r18 \n\t" |
| "adc r22, r22 \n\t" |
| "ld r18, x+ \n\t" |
| "mul r24, r18 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "mul r25, r21 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st z+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "add r22, r19 \n\t" |
| "adc r23, r23 \n\t" |
| "ld r19, x+ \n\t" |
| "mul r24, r19 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "mul r25, r18 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "st z+, r22 \n\t" |
| "ldi r22, 0 \n\t") |
| |
| "add r23, r20 \n\t" // 2 |
| "adc r22, r22 \n\t" |
| "ld r20, x+ \n\t" |
| "mul r24, r20 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "mul r25, r19 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st z+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "add r22, r21 \n\t" // 1 |
| "adc r23, r23 \n\t" |
| "ld r21, x+ \n\t" |
| "mul r24, r21 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "mul r25, r20 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "st z+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| /* Now finish the carries etc */ |
| "add r23, r18 \n\t" |
| "adc r22, r22 \n\t" |
| "mul r25, r21 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st z+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "add r22, r19 \n\t" |
| "adc r23, r23 \n\t" |
| "st z+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| "add r23, r20 \n\t" |
| "adc r22, r22 \n\t" |
| "st z+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "add r22, r21 \n\t" |
| "adc r23, r23 \n\t" |
| "st z+, r22 \n\t" |
| "st z+, r23 \n\t" |
| "eor r1, r1 \n\t" /* make r1 be 0 again */ |
| |
| "sbiw r30, 37 \n\t" /* move z back to point at tmp */ |
| "subi r26, 64 \n\t" /* move x back to point at product */ |
| "sbc r27, __zero_reg__ \n\t" |
| |
| /* add low bytes of tmp to product, storing in result */ |
| "ld r18, z+ \n\t" |
| "ld r19, x+ \n\t" |
| "add r18, r19 \n\t" |
| "st y+, r18 \n\t" |
| REPEAT(31, |
| "ld r18, z+ \n\t" |
| "ld r19, x+ \n\t" |
| "adc r18, r19 \n\t" |
| "st y+, r18 \n\t") |
| |
| "adc %[carry], __zero_reg__ \n\t" /* Store carry bit (carry flag is cleared). */ |
| /* at this point x is at the end of product, y is at the end of result, |
| z is 32 bytes into tmp */ |
| "sbiw r28, 32 \n\t" /* move y back to point at result */ |
| |
| /* do omega_mult again with the 5 relevant bytes */ |
| /* z points to tmp + uECC_WORDS, x points to the end of product */ |
| "sbiw r26, 32 \n\t" /* shift x back to point into the product buffer |
| (we can overwrite it now) */ |
| "ld r18, z+ \n\t" |
| "ld r19, z+ \n\t" |
| "ld r20, z+ \n\t" |
| "ld r21, z+ \n\t" |
| |
| "mul r24, r18 \n\t" |
| "st x+, r0 \n\t" |
| "mov r22, r1 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "mul r24, r19 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" /* can't overflow */ |
| "mul r25, r18 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" /* can't overflow */ |
| "st x+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| "mul r24, r20 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "mul r25, r19 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st x+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "mul r24, r21 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "mul r25, r20 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "st x+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| "add r23, r18 \n\t" |
| "adc r22, r22 \n\t" |
| "ld r18, z+ \n\t" |
| "mul r24, r18 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "mul r25, r21 \n\t" |
| "add r23, r0 \n\t" |
| "adc r22, r1 \n\t" |
| "st x+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| /* Now finish the carries etc */ |
| "add r22, r19 \n\t" |
| "adc r23, r23 \n\t" |
| "mul r25, r18 \n\t" |
| "add r22, r0 \n\t" |
| "adc r23, r1 \n\t" |
| "st x+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| "add r23, r20 \n\t" |
| "adc r22, r22 \n\t" |
| "st x+, r23 \n\t" |
| "ldi r23, 0 \n\t" |
| |
| "add r22, r21 \n\t" |
| "adc r23, r23 \n\t" |
| "st x+, r22 \n\t" |
| "ldi r22, 0 \n\t" |
| |
| "add r23, r18 \n\t" |
| "adc r22, r22 \n\t" |
| "st x+, r23 \n\t" |
| "st x+, r22 \n\t" |
| "eor r1, r1 \n\t" /* make r1 be 0 again */ |
| |
| /* now z points to the end of tmp, x points to the end of product |
| (y still points at result) */ |
| "sbiw r26, 10 \n\t" /* move x back to point at beginning of actual data */ |
| /* add into result */ |
| "ld r18, x+ \n\t" |
| "ld r19, y \n\t" |
| "add r18, r19 \n\t" |
| "st y+, r18 \n\t" |
| REPEAT(9, |
| "ld r18, x+ \n\t" |
| "ld r19, y \n\t" |
| "adc r18, r19 \n\t" |
| "st y+, r18 \n\t") |
| |
| /* Done adding, now propagate carry bit */ |
| REPEAT(22, |
| "ld r18, y \n\t" |
| "adc r18, __zero_reg__ \n\t" |
| "st y+, r18 \n\t") |
| |
| "adc %[carry], __zero_reg__ \n\t" /* Store carry bit (carry flag is cleared). */ |
| "sbiw r28, 32 \n\t" /* move y back to point at result */ |
| |
| "sbiw r30, 1 \n\t" /* fix stack pointer */ |
| "in r0, __SREG__ \n\t" |
| "cli \n\t" |
| "out __SP_H__, r31 \n\t" |
| "out __SREG__, r0 \n\t" |
| "out __SP_L__, r30 \n\t" |
| |
| : "+x" (product), [carry] "+r" (carry) |
| : "y" (result) |
| : "r0", "r18", "r19", "r20", "r21", "r22", "r23", "r24", "r25", "r30", "r31", "cc" |
| ); |
| |
| if (carry > 0) { |
| --carry; |
| uECC_vli_sub(result, result, curve_secp256k1.p, 32); |
| } |
| if (carry > 0) { |
| uECC_vli_sub(result, result, curve_secp256k1.p, 32); |
| } |
| if (uECC_vli_cmp_unsafe(result, curve_secp256k1.p, 32) > 0) { |
| uECC_vli_sub(result, result, curve_secp256k1.p, 32); |
| } |
| } |
| #define asm_mmod_fast_secp256k1 1 |
| #endif /* uECC_SUPPORTS_secp256k1 */ |
| |
| #endif /* (uECC_OPTIMIZATION_LEVEL >= 2) */ |
| |
| /* ---- "Small" implementations ---- */ |
| |
| #if !asm_add |
| uECC_VLI_API uECC_word_t uECC_vli_add(uECC_word_t *result, |
| const uECC_word_t *left, |
| const uECC_word_t *right, |
| wordcount_t num_words) { |
| volatile uECC_word_t *r = result; |
| uint8_t carry = 0; |
| uint8_t left_byte; |
| uint8_t right_byte; |
| |
| __asm__ volatile ( |
| "clc \n\t" |
| |
| "1: \n\t" |
| "ld %[left], x+ \n\t" /* Load left byte. */ |
| "ld %[right], y+ \n\t" /* Load right byte. */ |
| "adc %[left], %[right] \n\t" /* Add. */ |
| "st z+, %[left] \n\t" /* Store the result. */ |
| "dec %[i] \n\t" |
| "brne 1b \n\t" |
| |
| "adc %[carry], %[carry] \n\t" /* Store carry bit. */ |
| |
| : "+z" (r), "+x" (left), "+y" (right), [i] "+r" (num_words), |
| [carry] "+r" (carry), [left] "=&r" (left_byte), [right] "=&r" (right_byte) |
| : |
| : "cc" |
| ); |
| return carry; |
| } |
| #define asm_add 1 |
| #endif |
| |
| #if !asm_sub |
| uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result, |
| const uECC_word_t *left, |
| const uECC_word_t *right, |
| wordcount_t num_words) { |
| volatile uECC_word_t *r = result; |
| uint8_t borrow = 0; |
| uint8_t left_byte; |
| uint8_t right_byte; |
| |
| __asm__ volatile ( |
| "clc \n\t" |
| |
| "1: \n\t" |
| "ld %[left], x+ \n\t" /* Load left byte. */ |
| "ld %[right], y+ \n\t" /* Load right byte. */ |
| "sbc %[left], %[right] \n\t" /* Subtract. */ |
| "st z+, %[left] \n\t" /* Store the result. */ |
| "dec %[i] \n\t" |
| "brne 1b \n\t" |
| |
| "adc %[borrow], %[borrow] \n\t" /* Store carry bit in borrow. */ |
| |
| : "+z" (r), "+x" (left), "+y" (right), [i] "+r" (i), |
| [borrow] "+r" (borrow), [left] "=&r" (left_byte), [right] "=&r" (right_byte) |
| : |
| : "cc" |
| ); |
| return borrow; |
| } |
| #define asm_sub 1 |
| #endif |
| |
| #if !asm_mult |
| __attribute((noinline)) |
| uECC_VLI_API void uECC_vli_mult(uECC_word_t *result, |
| const uECC_word_t *left, |
| const uECC_word_t *right, |
| wordcount_t num_words) { |
| volatile uECC_word_t *r = result; |
| uint8_t r0 = 0; |
| uint8_t r1 = 0; |
| uint8_t r2 = 0; |
| uint8_t zero = 0; |
| uint8_t k, i; |
| |
| __asm__ volatile ( |
| "ldi %[k], 1 \n\t" /* k = 1; k < num_words; ++k */ |
| |
| "1: \n\t" |
| "ldi %[i], 0 \n\t" /* i = 0; i < k; ++i */ |
| |
| "add r28, %[k] \n\t" /* pre-add right ptr */ |
| "adc r29, %[zero] \n\t" |
| |
| "2: \n\t" |
| "ld r0, x+ \n\t" |
| "ld r1, -y \n\t" |
| "mul r0, r1 \n\t" |
| |
| "add %[r0], r0 \n\t" |
| "adc %[r1], r1 \n\t" |
| "adc %[r2], %[zero] \n\t" |
| |
| "inc %[i] \n\t" |
| "cp %[i], %[k] \n\t" |
| "brlo 2b \n\t" /* loop if i < k */ |
| |
| "sub r26, %[k] \n\t" /* fix up left ptr */ |
| "sbc r27, %[zero] \n\t" |
| |
| "st z+, %[r0] \n\t" /* Store the result. */ |
| "mov %[r0], %[r1] \n\t" |
| "mov %[r1], %[r2] \n\t" |
| "mov %[r2], %[zero] \n\t" |
| |
| "inc %[k] \n\t" |
| "cp %[k], %[num] \n\t" |
| "brlo 1b \n\t" /* loop if k < num_words */ |
| |
| /* second half */ |
| "mov %[k], %[num] \n\t" /* k = num_words; k > 0; --k */ |
| "add r28, %[num] \n\t" /* move right ptr to point at the end of right */ |
| "adc r29, %[zero] \n\t" |
| |
| "1: \n\t" |
| "ldi %[i], 0 \n\t" /* i = 0; i < k; ++i */ |
| |
| "2: \n\t" |
| "ld r0, x+ \n\t" |
| "ld r1, -y \n\t" |
| "mul r0, r1 \n\t" |
| |
| "add %[r0], r0 \n\t" |
| "adc %[r1], r1 \n\t" |
| "adc %[r2], %[zero] \n\t" |
| |
| "inc %[i] \n\t" |
| "cp %[i], %[k] \n\t" |
| "brlo 2b \n\t" /* loop if i < k */ |
| |
| "add r28, %[k] \n\t" /* fix up right ptr */ |
| "adc r29, %[zero] \n\t" |
| |
| "st z+, %[r0] \n\t" /* Store the result. */ |
| "mov %[r0], %[r1] \n\t" |
| "mov %[r1], %[r2] \n\t" |
| "mov %[r2], %[zero] \n\t" |
| |
| "dec %[k] \n\t" |
| "sub r26, %[k] \n\t" /* fix up left ptr (after k is decremented, so next time |
| we start 1 higher) */ |
| "sbc r27, %[zero] \n\t" |
| |
| "cp %[k], %[zero] \n\t" |
| "brne 1b \n\t" /* loop if k > 0 */ |
| |
| "st z+, %[r0] \n\t" /* Store last result byte. */ |
| "eor r1, r1 \n\t" /* fix r1 to be 0 again */ |
| |
| : "+z" (result), "+x" (left), "+y" (right), |
| [r0] "+r" (r0), [r1] "+r" (r1), [r2] "+r" (r2), |
| [zero] "+r" (zero), [num] "+r" (num_words), |
| [k] "=&r" (k), [i] "=&r" (i) |
| : |
| : "r0", "cc" |
| ); |
| } |
| #define asm_mult 1 |
| #endif |
| |
| #if (uECC_SQUARE_FUNC && !asm_square) |
| uECC_VLI_API void uECC_vli_square(uECC_word_t *result, |
| const uECC_word_t *left, |
| wordcount_t num_words) { |
| volatile uECC_word_t *r = result; |
| uint8_t r0 = 0; |
| uint8_t r1 = 0; |
| uint8_t r2 = 0; |
| uint8_t zero = 0; |
| uint8_t k; |
| |
| __asm__ volatile ( |
| "ldi %[k], 1 \n\t" /* k = 1; k < num_words * 2; ++k */ |
| |
| "1: \n\t" |
| |
| "movw r26, %[orig] \n\t" /* copy orig ptr to 'left' ptr */ |
| "movw r30, %[orig] \n\t" /* copy orig ptr to 'right' ptr */ |
| "cp %[k], %[num] \n\t" |
| "brlo 2f \n\t" |
| "breq 2f \n\t" |
| |
| /* when k > num_words, we start from (k - num_words) on the 'left' ptr */ |
| "add r26, %[k] \n\t" |
| "adc r27, %[zero] \n\t" |
| "sub r26, %[num] \n\t" |
| "sbc r27, %[zero] \n\t" |
| "add r30, %[num] \n\t" /* move right ptr to point at the end */ |
| "adc r31, %[zero] \n\t" |
| "rjmp 3f \n\t" |
| |
| "2: \n\t" /* when k <= num_words, we add k to the 'right' ptr */ |
| "add r30, %[k] \n\t" /* pre-add 'right' ptr */ |
| "adc r31, %[zero] \n\t" |
| |
| "3: \n\t" |
| "ld r0, x+ \n\t" |
| "cp r26, r30 \n\t" /* if left == right here, then we are done after this mult |
| (and we don't need to double) */ |
| "breq 4f \n\t" |
| "ld r1, -z \n\t" |
| "mul r0, r1 \n\t" |
| |
| /* add twice since it costs the same as doubling */ |
| "add %[r0], r0 \n\t" |
| "adc %[r1], r1 \n\t" |
| "adc %[r2], %[zero] \n\t" |
| "add %[r0], r0 \n\t" |
| "adc %[r1], r1 \n\t" |
| "adc %[r2], %[zero] \n\t" |
| |
| "cpse r26, r30 \n\t" /* if left == right here, then we are done */ |
| "rjmp 3b \n\t" |
| "rjmp 5f \n\t" /* skip code for non-doubled mult */ |
| |
| "4: \n\t" |
| "ld r1, -z \n\t" |
| "mul r0, r1 \n\t" |
| "add %[r0], r0 \n\t" |
| "adc %[r1], r1 \n\t" |
| "adc %[r2], %[zero] \n\t" |
| |
| "5: \n\t" |
| "movw r30, %[result] \n\t" /* make z point to result */ |
| "st z+, %[r0] \n\t" /* Store the result. */ |
| "movw %[result], r30 \n\t" /* update result ptr*/ |
| "mov %[r0], %[r1] \n\t" |
| "mov %[r1], %[r2] \n\t" |
| "mov %[r2], %[zero] \n\t" |
| |
| "inc %[k] \n\t" |
| "cp %[k], %[max] \n\t" |
| "brlo 1b \n\t" /* loop if k < num_words * 2 */ |
| |
| "movw r30, %[result] \n\t" /* make z point to result */ |
| "st z+, %[r0] \n\t" /* Store last result byte. */ |
| "eor r1, r1 \n\t" /* fix r1 to be 0 again */ |
| |
| : [result] "+r" (r), |
| [r0] "+r" (r0), [r1] "+r" (r1), [r2] "+r" (r2), [zero] "+r" (zero), |
| [k] "=&a" (k) |
| : [orig] "r" (left), [max] "r" ((uint8_t)(2 * num_words)), |
| [num] "r" (num_words) |
| : "r0", "r26", "r27", "r30", "r31", "cc" |
| ); |
| } |
| #define asm_square 1 |
| #endif /* uECC_SQUARE_FUNC && !asm_square */ |
| |
| #endif /* _UECC_ASM_AVR_H_ */ |
