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#include "devices.h"
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);
}
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