Allow mapping the PCI Config so Yellowstone can map it.

This is a temp system call. Evemtually we should probably supply the
root process with all of the system physical memory objects.

zion/include/zcall.h

@@ -32,6 +32,8 @@
 
 #define Z_MEMORY_OBJECT_CREATE 0x30
 
+#define Z_TEMP_PCIE_CONFIG_OBJECT_CREATE 0x3F
+
 #define Z_INIT_BOOT_VMMO 0x31
 
 // IPC Calls
@@ -65,6 +67,8 @@ void ZThreadExit();
 [[nodiscard]] z_err_t ZAddressSpaceMap(uint64_t vmas_cap, uint64_t vmas_offset,
                                        uint64_t vmmo_cap, uint64_t* vaddr);
 [[nodiscard]] z_err_t ZMemoryObjectCreate(uint64_t size, uint64_t* vmmo_cap);
+[[nodiscard]] z_err_t ZTempPcieConfigObjectCreate(uint64_t* vmmo_cap,
+                                                  uint64_t* vmmo_size);
 
 [[nodiscard]] z_err_t ZChannelCreate(uint64_t* channel1, uint64_t* channel2);
 [[nodiscard]] z_err_t ZChannelSend(uint64_t chan_cap, uint64_t type,

zion/object/memory_object.h

@@ -20,11 +20,28 @@ class MemoryObject : public KernelObject {
 
   void CopyBytesToObject(uint64_t source, uint64_t length);
 
+ protected:
+  // Hacky to avoid linked_list creation.
+  MemoryObject(uint64_t size, bool) : size_(size) {}
+
  private:
   // Always stores the full page-aligned size.
   uint64_t size_;
 
-  uint64_t PageNumberToPhysAddr(uint64_t page_num);
+  virtual uint64_t PageNumberToPhysAddr(uint64_t page_num);
 
   LinkedList<uint64_t> phys_page_list_;
 };
+
+class FixedMemoryObject : public MemoryObject {
+ public:
+  FixedMemoryObject(uint64_t physical_addr, uint64_t size)
+      : MemoryObject(size, true), physical_addr_(physical_addr) {}
+
+ private:
+  uint64_t physical_addr_;
+
+  uint64_t PageNumberToPhysAddr(uint64_t page_num) override {
+    return physical_addr_ + (0x1000 * page_num);
+  }
+};

zion/syscall/syscall.cpp

@@ -2,6 +2,7 @@
 
 #include <stdint.h>
 
+#include "boot/acpi.h"
 #include "common/msr.h"
 #include "debug/debug.h"
 #include "include/zcall.h"
@@ -129,6 +130,20 @@ z_err_t MemoryObjectCreate(ZMemoryObjectCreateReq* req,
   return Z_OK;
 }
 
+z_err_t TempPcieConfigObjectCreate(ZTempPcieConfigObjectCreateResp* resp) {
+  auto& curr_proc = gScheduler->CurrentProcess();
+  uint64_t pci_base, pci_size;
+  dbgln("Getting config");
+  RET_ERR(GetPciExtendedConfiguration(&pci_base, &pci_size));
+  dbgln("Making obj");
+  auto vmmo_ref = MakeRefCounted<FixedMemoryObject>(pci_base, pci_size);
+  dbgln("Adding cap");
+  resp->vmmo_cap =
+      curr_proc.AddCapability(StaticCastRefPtr<MemoryObject>(vmmo_ref));
+  resp->vmmo_size = pci_size;
+  return Z_OK;
+}
+
 z_err_t ChannelCreate(ZChannelCreateResp* resp) {
   auto& proc = gScheduler->CurrentProcess();
   auto chan_pair = Channel::CreateChannelPair();
@@ -186,6 +201,9 @@ extern "C" z_err_t SyscallHandler(uint64_t call_id, void* req, void* resp) {
       return MemoryObjectCreate(
           reinterpret_cast<ZMemoryObjectCreateReq*>(req),
           reinterpret_cast<ZMemoryObjectCreateResp*>(resp));
+    case Z_TEMP_PCIE_CONFIG_OBJECT_CREATE:
+      return TempPcieConfigObjectCreate(
+          reinterpret_cast<ZTempPcieConfigObjectCreateResp*>(resp));
     case Z_CHANNEL_CREATE:
       return ChannelCreate(reinterpret_cast<ZChannelCreateResp*>(resp));
     case Z_CHANNEL_SEND:

zion/usr/zcall.cpp

@@ -83,6 +83,14 @@ z_err_t ZMemoryObjectCreate(uint64_t size, uint64_t* vmmo_cap) {
   return ret;
 }
 
+z_err_t ZTempPcieConfigObjectCreate(uint64_t* vmmo_cap, uint64_t* vmmo_size) {
+  ZTempPcieConfigObjectCreateResp resp;
+  z_err_t ret = SysCall2(Z_TEMP_PCIE_CONFIG_OBJECT_CREATE, 0, &resp);
+  *vmmo_cap = resp.vmmo_cap;
+  *vmmo_size = resp.vmmo_size;
+  return ret;
+}
+
 z_err_t ZChannelCreate(uint64_t* channel1, uint64_t* channel2) {
   ZChannelCreateResp resp;
   z_err_t ret = SysCall2(Z_CHANNEL_CREATE, 0, &resp);

zion/usr/zcall_internal.h

@@ -46,6 +46,11 @@ struct ZMemoryObjectCreateResp {
   uint64_t vmmo_cap;
 };
 
+struct ZTempPcieConfigObjectCreateResp {
+  uint64_t vmmo_cap;
+  uint64_t vmmo_size;
+};
+
 struct ZChannelCreateResp {
   uint64_t chan_cap1;
   uint64_t chan_cap2;