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Merge 2302c5130d into 0454e023cd

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Joachim Strömbergson 2024-04-26 15:30:20 +02:00 committed by GitHub
parent 0454e023cd 2302c5130d
commit c3fe96ab88
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GPG Key ID: B5690EEEBB952194
1 changed files with 17 additions and 7 deletions
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24
hw/application_fpga/fw/tk1/main.c
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@ -363,24 +363,34 @@ static void run(const struct context *ctx)
__builtin_unreachable();
}
uint32_t xorwow(uint32_t state, uint32_t acc)
{
state ^= state << 13;
state ^= state >> 17;
state ^= state << 5;
state += acc;
return state;
}
static void scramble_ram(void)
{
uint32_t *ram = (uint32_t *)(TK1_RAM_BASE);
uint32_t rnd = rnd_word();
uint32_t rnd_incr = rnd_word();
// Set RAM address and data scrambling values
*ram_rand = rnd_word();
*ram_scramble = rnd_word();
// Fill RAM with random data (FW does not use RAM, has its stack in
// FW_RAM)
// Get random state and accumulator seeds.
uint32_t data_state = rnd_word();
uint32_t data_acc = rnd_word();
for (uint32_t w = 0; w < TK1_RAM_SIZE / 4; w++) {
ram[w] = rnd;
rnd += rnd_incr;
data_state = xorwow(data_state, data_acc);
ram[w] = data_state;
}
// Set new scrambling values, for all use of RAM by app
// Set new address and RAM scrambling values,
// for all use of RAM by app.
*ram_rand = rnd_word();
*ram_scramble = rnd_word();
}