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#include "devices.h"
#include "mmu.h"
#include <stdexcept>
mmio_device_map_t& mmio_device_map()
{
static mmio_device_map_t device_map;
return device_map;
}
void bus_t::add_device(reg_t addr, abstract_device_t* dev)
{
// Searching devices via lower_bound/upper_bound
// implicitly relies on the underlying std::map
// container to sort the keys and provide ordered
// iteration over this sort, which it does. (python's
// SortedDict is a good analogy)
devices[addr] = dev;
}
bool bus_t::load(reg_t addr, size_t len, uint8_t* bytes)
{
// Find the device with the base address closest to but
// less than addr (price-is-right search)
auto it = devices.upper_bound(addr);
if (devices.empty() || it == devices.begin()) {
// Either the bus is empty, or there weren't
// any items with a base address <= addr
return false;
}
// Found at least one item with base address <= addr
// The iterator points to the device after this, so
// go back by one item.
it--;
return it->second->load(addr - it->first, len, bytes);
}
bool bus_t::store(reg_t addr, size_t len, const uint8_t* bytes)
{
// See comments in bus_t::load
auto it = devices.upper_bound(addr);
if (devices.empty() || it == devices.begin()) {
return false;
}
it--;
return it->second->store(addr - it->first, len, bytes);
}
std::pair<reg_t, abstract_device_t*> bus_t::find_device(reg_t addr)
{
// See comments in bus_t::load
auto it = devices.upper_bound(addr);
if (devices.empty() || it == devices.begin()) {
return std::make_pair((reg_t)0, (abstract_device_t*)NULL);
}
it--;
return std::make_pair(it->first, it->second);
}
mem_t::mem_t(reg_t size)
: sz(size)
{
if (size == 0 || size % PGSIZE != 0)
throw std::runtime_error("memory size must be a positive multiple of 4 KiB");
}
mem_t::~mem_t()
{
for (auto& entry : sparse_memory_map)
free(entry.second);
}
bool mem_t::load_store(reg_t addr, size_t len, uint8_t* bytes, bool store)
{
if (addr + len < addr || addr + len > sz)
return false;
while (len > 0) {
auto n = std::min(PGSIZE - (addr % PGSIZE), reg_t(len));
if (store)
memcpy(this->contents(addr), bytes, n);
else
memcpy(bytes, this->contents(addr), n);
addr += n;
bytes += n;
len -= n;
}
return true;
}
char* mem_t::contents(reg_t addr) {
reg_t ppn = addr >> PGSHIFT, pgoff = addr % PGSIZE;
auto search = sparse_memory_map.find(ppn);
if (search == sparse_memory_map.end()) {
auto res = (char*)calloc(PGSIZE, 1);
if (res == nullptr)
throw std::bad_alloc();
sparse_memory_map[ppn] = res;
return res + pgoff;
}
return search->second + pgoff;
}
void mem_t::dump(std::ostream& o) {
const char empty[PGSIZE] = {0};
for (reg_t i = 0; i < sz; i += PGSIZE) {
reg_t ppn = i >> PGSHIFT;
auto search = sparse_memory_map.find(ppn);
if (search == sparse_memory_map.end()) {
o.write(empty, PGSIZE);
} else {
o.write(sparse_memory_map[ppn], PGSIZE);
}
}
}
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