Support more flexible main memory allocation

1 files changed, 23 insertions, 0 deletions

diff --git a/riscv/devices.h b/riscv/devices.h
index f3ecb67..ba344db 100644
--- a/riscv/devices.h
+++ b/riscv/devices.h
@@ -20,6 +20,9 @@ class bus_t : public abstract_device_t {
   bool store(reg_t addr, size_t len, const uint8_t* bytes);
   void add_device(reg_t addr, abstract_device_t* dev);
 
+  struct descriptor { reg_t base; abstract_device_t* device; };
+  descriptor find_device(reg_t addr);
+
  private:
   std::map<reg_t, abstract_device_t*> devices;
 };
@@ -34,6 +37,26 @@ class rom_device_t : public abstract_device_t {
   std::vector<char> data;
 };
 
+class mem_t : public abstract_device_t {
+ public:
+  mem_t(size_t size) : len(size) {
+    data = (char*)calloc(1, size);
+    if (!data)
+      throw std::runtime_error("couldn't allocate " + std::to_string(size) + " bytes of target memory");
+  }
+  mem_t(const mem_t& that) = delete;
+  ~mem_t() { free(data); }
+
+  bool load(reg_t addr, size_t len, uint8_t* bytes) { return false; }
+  bool store(reg_t addr, size_t len, const uint8_t* bytes) { return false; }
+  char* contents() { return data; }
+  size_t size() { return len; }
+
+ private:
+  char* data;
+  size_t len;
+};
+
 class clint_t : public abstract_device_t {
  public:
   clint_t(std::vector<processor_t*>&);