Add a yellowstone stub and partially migrate denali

sys/yellowstone/CMakeLists.txt

@@ -4,7 +4,8 @@ add_executable(yellowstone
   yellowstone.cpp
   yellowstone_server.cpp
   )
- target_include_directories(yellowstone
+
+target_include_directories(yellowstone
    PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 
 target_link_libraries(yellowstone
@@ -27,6 +28,10 @@ target_include_directories(yellowstone_stub
    PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
    PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/include")
 
+target_link_libraries(yellowstone_stub
+  mammoth
+  )
+
 set_target_properties(yellowstone_stub PROPERTIES
   COMPILE_FLAGS "${CMAKE_CXX_FLAGS} ${BASE_COMPILE_FLAGS}"
   LINK_FLAGS "${CMAKE_EXE_LINK_FLAGS} ${BASE_LINK_FLAGS}"

sys/yellowstone/include/yellowstone_stub.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <mammoth/endpoint_client.h>
+#include <mammoth/memory_region.h>
+#include <ztypes.h>
+
+class YellowstoneStub {
+ public:
+  explicit YellowstoneStub(z_cap_t yellowstone_cap);
+
+  glcr::ErrorOr<MappedMemoryRegion> GetAhciConfig();
+
+ private:
+  glcr::UniquePtr<EndpointClient> yellowstone_stub_;
+};

sys/yellowstone/stub/yellowstone_stub.cpp

@@ -1,3 +1,23 @@
-// PLACEHOLDER
-#include <stdint.h>
-uint64_t a = 0;
+#include "include/yellowstone_stub.h"
+
+#include "include/yellowstone.h"
+
+namespace {
+
+const uint64_t kPciSize = 0x1000;
+
+}  // namespace
+
+YellowstoneStub::YellowstoneStub(z_cap_t yellowstone_cap)
+    : yellowstone_stub_(EndpointClient::AdoptEndpoint(yellowstone_cap)) {}
+
+glcr::ErrorOr<MappedMemoryRegion> YellowstoneStub::GetAhciConfig() {
+  YellowstoneGetReq req{
+      .type = kYellowstoneGetAhci,
+  };
+  ASSIGN_OR_RETURN(
+      YellowstoneGetAhciResp resp,
+      (yellowstone_stub_
+           ->CallEndpoint<YellowstoneGetReq, YellowstoneGetAhciResp>(req)));
+  return MappedMemoryRegion::DirectPhysical(resp.ahci_phys_offset, kPciSize);
+}