npc: wip, cannot build

npc/csrc/devices/CMakeLists.txt

@@ -0,0 +1,3 @@
+add_library(devices serial.cpp rtc.cpp)
+
+target_include_directories(devices PUBLIC include)

npc/csrc/devices/include/devices.hpp

@@ -0,0 +1,85 @@
+#include <array>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+#include <initializer_list>
+#include <iostream>
+#include <iterator>
+#include <map>
+#include <memory>
+#include <unordered_map>
+#include <utility>
+
+namespace Devices {
+class Device {
+public:
+  uint8_t *p_buf;
+  uint64_t addr;
+  size_t len;
+  Device(uint64_t addr, size_t len, uint8_t buf[])
+      : addr(addr), len(len), p_buf(buf) {}
+  virtual ~Device(){};
+  virtual void io_handler(uint32_t offset, size_t len, bool is_write) = 0;
+  void transfer(uint8_t *src, size_t len, bool is_write) {
+    if (is_write) {
+      memmove(p_buf, src, len);
+    } else {
+      memmove(src, p_buf, len);
+    }
+  };
+};
+
+class Serial : public Device {
+  uint8_t buf[1];
+
+public:
+  Serial(uint64_t addr, size_t len);
+  ~Serial() override{};
+  void io_handler(uint32_t offset, size_t len, bool is_write) override;
+  // void transfer(uint8_t *src, size_t len, bool is_write) override;
+};
+
+class RTC : public Device {
+  uint8_t buf[8];
+  uint64_t boot_time;
+  uint64_t get_time_internal();
+  uint64_t get_time();
+
+public:
+  RTC(uint64_t addr, size_t len);
+  ~RTC() override{};
+  void io_handler(uint32_t offset, size_t len, bool is_write) override;
+  // void transfer(uint8_t *src, size_t len, bool is_write) override;
+};
+
+class DeviceMap {
+  std::map<uint64_t, Device *> addr_to_device;
+
+public:
+  DeviceMap(std::initializer_list<Device *> devices) {
+    for (auto device : devices) {
+      addr_to_device.insert(std::make_pair(device->addr, device));
+    }
+  }
+  bool handle(uint64_t addr, uint8_t *data, size_t len, bool is_write) {
+    auto it = addr_to_device.upper_bound(addr);
+    if (it == addr_to_device.begin() ||
+        (--it)->second->addr + it->second->len <= addr) {
+      std::cerr << "Use of a unintialized device at memory addr: 0x" << std::hex
+                << addr << std::dec << std::endl;
+      return false;
+    }
+    auto &device = it->second;
+    uint32_t offset = addr - device->addr;
+    if (is_write) {
+      device->transfer(data, len, is_write);
+      device->io_handler(offset, len, is_write);
+    } else {
+      device->io_handler(offset, len, is_write);
+      device->transfer(data, len, is_write);
+    }
+    return true;
+  }
+};
+} // namespace Devices

npc/csrc/devices/rtc.cpp

@@ -0,0 +1,49 @@
+#include <cstdint>
+#include <devices.hpp>
+
+namespace Devices {
+uint64_t RTC::get_time_internal() {
+#if defined(CONFIG_TARGET_AM)
+  uint64_t us = io_read(AM_TIMER_UPTIME).us;
+#elif defined(CONFIG_TIMER_GETTIMEOFDAY)
+  struct timeval now;
+  gettimeofday(&now, NULL);
+  uint64_t us = now.tv_sec * 1000000 + now.tv_usec;
+#else
+  struct timespec now;
+  clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
+  uint64_t us = now.tv_sec * 1000000 + now.tv_nsec / 1000;
+#endif
+  return us;
+}
+
+uint64_t RTC::get_time() {
+  if (boot_time == 0)
+    boot_time = get_time_internal();
+  uint64_t now = get_time_internal();
+  return now - boot_time;
+}
+
+RTC::RTC(uint64_t addr, size_t len) : Device(addr, len, buf) {
+  *(uint64_t *)buf = 0;
+};
+
+void RTC::io_handler(uint32_t offset, size_t len, bool is_write) {
+  assert(offset == 0 || offset == 4);
+  if (!is_write && offset == 4) {
+    uint64_t us = get_time();
+    buf[0] = (uint32_t)us;
+    buf[1] = us >> 32;
+  }
+}
+
+// void RTC::transfer(uint8_t *src, size_t len, bool is_write) {
+//   if (is_write) {
+//     for (size_t i = 0; i < len; i++)
+//       buf[i] = src[i];
+//   } else {
+//     for (size_t i = 0; i < len; i++)
+//       src[i] = buf[i];
+//   }
+// }
+} // namespace Devices

npc/csrc/devices/serial.cpp

@@ -0,0 +1,22 @@
+#include <devices.hpp>
+#include <iostream>
+
+namespace Devices {
+Serial::Serial(uint64_t addr, size_t len) : Device(addr, len, buf) {
+  buf[0] = 0;
+};
+void Serial::io_handler(uint32_t offset, size_t len, bool is_write) {
+  if (is_write) {
+    std::cout << (char)buf[0];
+  }
+}
+// void Serial::transfer(uint8_t *src, size_t len, bool is_write) {
+//   if (is_write) {
+//     for (size_t i = 0; i < len; i++)
+//       buf[i] = src[i];
+//   } else {
+//     for (size_t i = 0; i < len; i++)
+//       src[i] = buf[i];
+//   }
+// }
+} // namespace Devices