KEK/mmu.cpp
2024-04-25 13:24:32 +02:00

222 lines
5 KiB
C++

#include <cassert>
#include <cstring>
#include "gen.h"
#include "log.h"
#include "mmu.h"
#include "utils.h"
mmu::mmu()
{
}
mmu::~mmu()
{
}
void mmu::reset()
{
memset(pages, 0x00, sizeof pages);
CPUERR = MMR0 = MMR1 = MMR2 = MMR3 = PIR = CSR = 0;
}
uint16_t mmu::read_pdr(const uint32_t a, const int run_mode)
{
int page = (a >> 1) & 7;
bool is_d = a & 16;
uint16_t t = pages[run_mode][is_d][page].pdr;
return t;
}
uint16_t mmu::read_par(const uint32_t a, const int run_mode)
{
int page = (a >> 1) & 7;
bool is_d = a & 16;
uint16_t t = pages[run_mode][is_d][page].par;
return t;
}
void mmu::setMMR0(uint16_t value)
{
value &= ~(3 << 10); // bit 10 & 11 always read as 0
if (value & 1)
value &= ~(7l << 13); // reset error bits
if (MMR0 & 0160000) {
if ((value & 1) == 0)
value &= 254; // bits 7...1 are protected
}
// TODO if bit 15/14/13 are set (either of them), then do not modify bit 1...7
MMR0 = value;
}
void mmu::setMMR0Bit(const int bit)
{
assert(bit != 10 && bit != 11);
assert(bit < 16 && bit >= 0);
MMR0 |= 1 << bit;
}
void mmu::clearMMR0Bit(const int bit)
{
assert(bit != 10 && bit != 11);
assert(bit < 16 && bit >= 0);
MMR0 &= ~(1 << bit);
}
void mmu::setMMR2(const uint16_t value)
{
MMR2 = value;
}
void mmu::setMMR3(const uint16_t value)
{
MMR3 = value;
}
bool mmu::get_use_data_space(const int run_mode) const
{
constexpr const int di_ena_mask[4] = { 4, 2, 0, 1 };
return !!(MMR3 & di_ena_mask[run_mode]);
}
void mmu::clearMMR1()
{
MMR1 = 0;
}
void mmu::addToMMR1(const int8_t delta, const uint8_t reg)
{
assert(reg >= 0 && reg <= 7);
assert(delta >= -2 && delta <= 2);
assert((getMMR0() & 0160000) == 0); // MMR1 should not be locked
#if defined(ESP32)
// if (MMR1 > 255)
// esp_backtrace_print(32);
#else
if (MMR1 > 255) {
extern FILE *lfh;
fflush(lfh);
}
assert(MMR1 < 256);
#endif
MMR1 <<= 8;
MMR1 |= (delta & 31) << 3;
MMR1 |= reg;
}
void mmu::write_pdr(const uint32_t a, const int run_mode, const uint16_t value, const word_mode_t word_mode)
{
bool is_d = a & 16;
int page = (a >> 1) & 7;
if (word_mode == wm_byte) {
assert(a != 0 || value < 256);
update_word(&pages[run_mode][is_d][page].pdr, a & 1, value);
}
else {
pages[run_mode][is_d][page].pdr = value;
}
pages[run_mode][is_d][page].pdr &= ~(32768 + 128 /*A*/ + 64 /*W*/ + 32 + 16); // set bit 4, 5 & 15 to 0 as they are unused and A/W are set to 0 by writes
DOLOG(debug, false, "mmu WRITE-I/O PDR run-mode %d: %c for %d: %o [%d]", run_mode, is_d ? 'D' : 'I', page, value, word_mode);
}
void mmu::write_par(const uint32_t a, const int run_mode, const uint16_t value, const word_mode_t word_mode)
{
bool is_d = a & 16;
int page = (a >> 1) & 7;
if (word_mode == wm_byte)
update_word(&pages[run_mode][is_d][page].par, a & 1, value);
else
pages[run_mode][is_d][page].par = value;
pages[run_mode][is_d][page].pdr &= ~(128 /*A*/ + 64 /*W*/); // reset PDR A/W when PAR is written to
DOLOG(debug, false, "mmu WRITE-I/O PAR run-mode %d: %c for %d: %o (%07o)", run_mode, is_d ? 'D' : 'I', page, word_mode == wm_byte ? value & 0xff : value, pages[run_mode][is_d][page].par * 64);
}
uint16_t mmu::readWord(const uint16_t a)
{
uint16_t v = 0;
if (a >= ADDR_PDR_SV_START && a < ADDR_PDR_SV_END)
v = read_pdr(a, 1);
else if (a >= ADDR_PAR_SV_START && a < ADDR_PAR_SV_END)
v = read_par(a, 1);
else if (a >= ADDR_PDR_K_START && a < ADDR_PDR_K_END)
v = read_pdr(a, 0);
else if (a >= ADDR_PAR_K_START && a < ADDR_PAR_K_END)
v = read_par(a, 0);
else if (a >= ADDR_PDR_U_START && a < ADDR_PDR_U_END)
v = read_pdr(a, 3);
else if (a >= ADDR_PAR_U_START && a < ADDR_PAR_U_END)
v = read_par(a, 3);
return v;
}
uint8_t mmu::readByte(const uint16_t addr)
{
uint16_t v = readWord(addr);
if (addr & 1)
return v >> 8;
return v;
}
void mmu::writeWord(const uint16_t a, const uint16_t value)
{
// supervisor
if (a >= ADDR_PDR_SV_START && a < ADDR_PDR_SV_END)
write_pdr(a, 1, value, wm_word);
else if (a >= ADDR_PAR_SV_START && a < ADDR_PAR_SV_END)
write_par(a, 1, value, wm_word);
// kernel
else if (a >= ADDR_PDR_K_START && a < ADDR_PDR_K_END)
write_pdr(a, 0, value, wm_word);
else if (a >= ADDR_PAR_K_START && a < ADDR_PAR_K_END)
write_par(a, 0, value, wm_word);
// user
else if (a >= ADDR_PDR_U_START && a < ADDR_PDR_U_END)
write_pdr(a, 3, value, wm_word);
else if (a >= ADDR_PAR_U_START && a < ADDR_PAR_U_END)
write_par(a, 3, value, wm_word);
}
void mmu::writeByte(const uint16_t a, const uint8_t value)
{
// supervisor
if (a >= ADDR_PDR_SV_START && a < ADDR_PDR_SV_END)
write_pdr(a, 1, value, wm_byte);
else if (a >= ADDR_PAR_SV_START && a < ADDR_PAR_SV_END)
write_par(a, 1, value, wm_byte);
// kernel
else if (a >= ADDR_PDR_K_START && a < ADDR_PDR_K_END)
write_pdr(a, 0, value, wm_byte);
else if (a >= ADDR_PAR_K_START && a < ADDR_PAR_K_END)
write_par(a, 0, value, wm_byte);
// user
else if (a >= ADDR_PDR_U_START && a < ADDR_PDR_U_END)
write_pdr(a, 3, value, wm_byte);
else if (a >= ADDR_PAR_U_START && a < ADDR_PAR_U_END)
write_par(a, 3, value, wm_byte);
}