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Emulate SRAM bank boundaries in PI read/write

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Christopher Bonhage 2021-11-30 10:44:14 -05:00 committed by Simon Eriksson
parent 6b7c2af8d4
commit 9f264b3208
1 changed files with 6 additions and 2 deletions
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8
pi/controller.c
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@ -65,7 +65,9 @@ static int pi_dma_read(struct pi_controller *pi) {
uint32_t sram_bank = (dest >> 18) & 3;
// SRAM bank capacity is 256Kbits (0x8000 bytes)
uint32_t sram_offset = (sram_bank * 0x8000) + (dest & 0x7FFF);
if (sram_offset + length <= pi->sram->size)
// Check SRAM address boundaries to prevent contiguous access across banks
uint32_t sram_bank_end = (sram_offset + length - 1) / 0x8000;
if (sram_bank == sram_bank_end && sram_offset + length <= pi->sram->size)
memcpy((uint8_t *) (pi->sram->ptr) + sram_offset, pi->bus->ri->ram + source, length);
}
// FlashRAM: Save the RDRAM destination address. Writing happens
@ -122,7 +124,9 @@ static int pi_dma_write(struct pi_controller *pi) {
uint32_t sram_bank = (source >> 18) & 3;
// SRAM bank capacity is 256Kbits (0x8000 bytes)
uint32_t sram_offset = (sram_bank * 0x8000) + (source & 0x7FFF);
if (sram_offset + length <= pi->sram->size)
// Check SRAM address boundaries to prevent contiguous access across banks
uint32_t sram_bank_end = (sram_offset + length - 1) / 0x8000;
if (sram_bank == sram_bank_end && sram_offset + length <= pi->sram->size)
memcpy(pi->bus->ri->ram + dest, (const uint8_t *) (pi->sram->ptr) + sram_offset, length);
}
// FlashRAM