uboot 2009（iMX25 处理器）上的慢散列（sha256）

Question

以下计算是在 iMX25 处理器上使用 uboot（2009 旧版本）完成的。我在uboot下运行ning sha256_process()函数(sha256.c)处理50Mbytes的数据得到hash。完成计算需要 100 多秒。如果运行在 Ubuntu（同一处理器）下使用 openssl，则相同的散列不需要时间。

交叉编译器： arm-none-linux-gnueabi-gcc 4.4.1.

需要一些关于可能是什么问题的意见。

尝试了另一个改进的 arm 工具链，但仍然不如预期。

---sha256编码。

static void sha256_process(sha256_context *ctx, const uint8_t data[64])
{
    uint32_t temp1, temp2;
    uint32_t W[64];
    uint32_t A, B, C, D, E, F, G, H;

    GET_UINT32_BE(W[0], data, 0);
    GET_UINT32_BE(W[1], data, 4);
    GET_UINT32_BE(W[2], data, 8);
    GET_UINT32_BE(W[3], data, 12);
    GET_UINT32_BE(W[4], data, 16);
    GET_UINT32_BE(W[5], data, 20);
    GET_UINT32_BE(W[6], data, 24);
    GET_UINT32_BE(W[7], data, 28);
    GET_UINT32_BE(W[8], data, 32);
    GET_UINT32_BE(W[9], data, 36);
    GET_UINT32_BE(W[10], data, 40);
    GET_UINT32_BE(W[11], data, 44);
    GET_UINT32_BE(W[12], data, 48);
    GET_UINT32_BE(W[13], data, 52);
    GET_UINT32_BE(W[14], data, 56);
    GET_UINT32_BE(W[15], data, 60);

#define SHR(x,n) ((x & 0xFFFFFFFF) >> n)
#define ROTR(x,n) (SHR(x,n) | (x << (32 - n)))

#define S0(x) (ROTR(x, 7) ^ ROTR(x,18) ^ SHR(x, 3))
#define S1(x) (ROTR(x,17) ^ ROTR(x,19) ^ SHR(x,10))

#define S2(x) (ROTR(x, 2) ^ ROTR(x,13) ^ ROTR(x,22))
#define S3(x) (ROTR(x, 6) ^ ROTR(x,11) ^ ROTR(x,25))

#define F0(x,y,z) ((x & y) | (z & (x | y)))
#define F1(x,y,z) (z ^ (x & (y ^ z)))

#define R(t)                    \
(                       \
    W[t] = S1(W[t - 2]) + W[t - 7] +    \
        S0(W[t - 15]) + W[t - 16]   \
)

#define P(a,b,c,d,e,f,g,h,x,K) {        \
    temp1 = h + S3(e) + F1(e,f,g) + K + x;  \
    temp2 = S2(a) + F0(a,b,c);      \
    d += temp1; h = temp1 + temp2;      \
}

    A = ctx->state[0];
    B = ctx->state[1];
    C = ctx->state[2];
    D = ctx->state[3];
    E = ctx->state[4];
    F = ctx->state[5];
    G = ctx->state[6];
    H = ctx->state[7];

    P(A, B, C, D, E, F, G, H, W[0], 0x428A2F98);
    P(H, A, B, C, D, E, F, G, W[1], 0x71374491);
    P(G, H, A, B, C, D, E, F, W[2], 0xB5C0FBCF);
    P(F, G, H, A, B, C, D, E, W[3], 0xE9B5DBA5);
    P(E, F, G, H, A, B, C, D, W[4], 0x3956C25B);
    P(D, E, F, G, H, A, B, C, W[5], 0x59F111F1);
    P(C, D, E, F, G, H, A, B, W[6], 0x923F82A4);
    P(B, C, D, E, F, G, H, A, W[7], 0xAB1C5ED5);
    P(A, B, C, D, E, F, G, H, W[8], 0xD807AA98);
    P(H, A, B, C, D, E, F, G, W[9], 0x12835B01);
    P(G, H, A, B, C, D, E, F, W[10], 0x243185BE);
    P(F, G, H, A, B, C, D, E, W[11], 0x550C7DC3);
    P(E, F, G, H, A, B, C, D, W[12], 0x72BE5D74);
    P(D, E, F, G, H, A, B, C, W[13], 0x80DEB1FE);
    P(C, D, E, F, G, H, A, B, W[14], 0x9BDC06A7);
    P(B, C, D, E, F, G, H, A, W[15], 0xC19BF174);
    P(A, B, C, D, E, F, G, H, R(16), 0xE49B69C1);
    P(H, A, B, C, D, E, F, G, R(17), 0xEFBE4786);
    P(G, H, A, B, C, D, E, F, R(18), 0x0FC19DC6);
    P(F, G, H, A, B, C, D, E, R(19), 0x240CA1CC);
    P(E, F, G, H, A, B, C, D, R(20), 0x2DE92C6F);
    P(D, E, F, G, H, A, B, C, R(21), 0x4A7484AA);
    P(C, D, E, F, G, H, A, B, R(22), 0x5CB0A9DC);
    P(B, C, D, E, F, G, H, A, R(23), 0x76F988DA);
    P(A, B, C, D, E, F, G, H, R(24), 0x983E5152);
    P(H, A, B, C, D, E, F, G, R(25), 0xA831C66D);
    P(G, H, A, B, C, D, E, F, R(26), 0xB00327C8);
    P(F, G, H, A, B, C, D, E, R(27), 0xBF597FC7);
    P(E, F, G, H, A, B, C, D, R(28), 0xC6E00BF3);
    P(D, E, F, G, H, A, B, C, R(29), 0xD5A79147);
    P(C, D, E, F, G, H, A, B, R(30), 0x06CA6351);
    P(B, C, D, E, F, G, H, A, R(31), 0x14292967);
    P(A, B, C, D, E, F, G, H, R(32), 0x27B70A85);
    P(H, A, B, C, D, E, F, G, R(33), 0x2E1B2138);
    P(G, H, A, B, C, D, E, F, R(34), 0x4D2C6DFC);
    P(F, G, H, A, B, C, D, E, R(35), 0x53380D13);
    P(E, F, G, H, A, B, C, D, R(36), 0x650A7354);
    P(D, E, F, G, H, A, B, C, R(37), 0x766A0ABB);
    P(C, D, E, F, G, H, A, B, R(38), 0x81C2C92E);
    P(B, C, D, E, F, G, H, A, R(39), 0x92722C85);
    P(A, B, C, D, E, F, G, H, R(40), 0xA2BFE8A1);
    P(H, A, B, C, D, E, F, G, R(41), 0xA81A664B);
    P(G, H, A, B, C, D, E, F, R(42), 0xC24B8B70);
    P(F, G, H, A, B, C, D, E, R(43), 0xC76C51A3);
    P(E, F, G, H, A, B, C, D, R(44), 0xD192E819);
    P(D, E, F, G, H, A, B, C, R(45), 0xD6990624);
    P(C, D, E, F, G, H, A, B, R(46), 0xF40E3585);
    P(B, C, D, E, F, G, H, A, R(47), 0x106AA070);
    P(A, B, C, D, E, F, G, H, R(48), 0x19A4C116);
    P(H, A, B, C, D, E, F, G, R(49), 0x1E376C08);
    P(G, H, A, B, C, D, E, F, R(50), 0x2748774C);
    P(F, G, H, A, B, C, D, E, R(51), 0x34B0BCB5);
    P(E, F, G, H, A, B, C, D, R(52), 0x391C0CB3);
    P(D, E, F, G, H, A, B, C, R(53), 0x4ED8AA4A);
    P(C, D, E, F, G, H, A, B, R(54), 0x5B9CCA4F);
    P(B, C, D, E, F, G, H, A, R(55), 0x682E6FF3);
    P(A, B, C, D, E, F, G, H, R(56), 0x748F82EE);
    P(H, A, B, C, D, E, F, G, R(57), 0x78A5636F);
    P(G, H, A, B, C, D, E, F, R(58), 0x84C87814);
    P(F, G, H, A, B, C, D, E, R(59), 0x8CC70208);
    P(E, F, G, H, A, B, C, D, R(60), 0x90BEFFFA);
    P(D, E, F, G, H, A, B, C, R(61), 0xA4506CEB);
    P(C, D, E, F, G, H, A, B, R(62), 0xBEF9A3F7);
    P(B, C, D, E, F, G, H, A, R(63), 0xC67178F2);

    ctx->state[0] += A;
    ctx->state[1] += B;
    ctx->state[2] += C;
    ctx->state[3] += D;
    ctx->state[4] += E;
    ctx->state[5] += F;
    ctx->state[6] += G;
    ctx->state[7] += H;
}

预计散列时间将在几秒内，而不是 100 秒。

Answer 1

您注意到的性能差异可能是由于 CPU Instructions/Data 缓存之一被禁用造成的。

如果它是使用 icache/dcache 命令编译的，您可以 enable/disable 来自 u-boot 的两个缓存。

如果您的 u-boot 还没有包含 icache/dcache 命令，您可能必须在将以下行添加到配置文件后重新编译它：CONFIG_CMD_CACHE=y.

另一种选择是在开始计算哈希之前以编程方式在您的代码中启用它。

uboot 2009（iMX25 处理器）上的慢散列（sha256）

slow hashing (sha256) on uboot 2009 (iMX25 processor)

hash

u-boot