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Implement external PIF RAM read/write.

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This commit is contained in:
Tyler Stachecki 2014-04-18 14:15:18 -04:00
parent 80fdac1231
commit b3e5d94811
2 changed files with 28 additions and 4 deletions
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30
si/controller.c
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@ -33,6 +33,20 @@ int si_init(struct si_controller *si,
// Reads a word from PIF RAM.
int read_pif_ram(void *opaque, uint32_t address, uint32_t *word) {
struct si_controller *si = (struct si_controller *) opaque;
unsigned offset = (address - PIF_RAM_BASE_ADDRESS) & 0x3F;
if (offset == 0x24)
si->pif_status = 0x80;
else if (offset == 0x3C)
*word = si->pif_status;
else {
memcpy(&word, si->ram + offset, sizeof(word));
*word = byteswap_32(*word);
}
return 0;
}
@ -58,16 +72,24 @@ int read_si_regs(void *opaque, uint32_t address, uint32_t *word) {
// Writes a word to PIF RAM.
int write_pif_ram(void *opaque, uint32_t address, uint32_t word, uint32_t dqm) {
assert(0 && "Attempt to write to PIF RAM.");
struct si_controller *si = (struct si_controller *) opaque;
unsigned offset = (address - PIF_RAM_BASE_ADDRESS) & 0x3F;
uint32_t orig_word;
return -1;
memcpy(&orig_word, si->ram + offset, sizeof(orig_word));
orig_word = byteswap_32(orig_word) & ~dqm;
word = byteswap_32(orig_word | word);
memcpy(si->ram + offset, &word, sizeof(word));
// TODO/FIXME: Raise exception.
si->regs[SI_STATUS_REG] |= 0x1000;
return 0;
}
// Writes a word to PIF ROM.
int write_pif_rom(void *opaque, uint32_t address, uint32_t word, uint32_t dqm) {
assert(0 && "Attempt to write to PIF ROM.");
return -1;
return 0;
}
// Writes a word to the SI MMIO register space.

2
si/controller.h
View file

@ -28,8 +28,10 @@ extern const char *si_register_mnemonics[NUM_SI_REGISTERS];
struct si_controller {
struct bus_controller *bus;
const uint8_t *rom;
uint8_t ram[64];
uint32_t regs[NUM_SI_REGISTERS];
uint32_t pif_status;
};
int si_init(struct si_controller *si,