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.

sys/yellowstone/CMakeLists.txt

@@ -1,5 +1,9 @@
 add_executable(yellowstone
-  yellowstone.cpp)
+  hw/pcie.cpp
+  yellowstone.cpp
+  )
+ target_include_directories(yellowstone
+   PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 
 target_link_libraries(yellowstone
   cxx

sys/yellowstone/hw/pcie.cpp

@@ -0,0 +1,61 @@
+#include "hw/pcie.h"
+
+#include <mammoth/debug.h>
+#include <zcall.h>
+
+namespace {
+
+struct PciDeviceHeader {
+  uint16_t vendor_id;
+  uint16_t device_id;
+  uint16_t command_reg;
+  uint16_t status_reg;
+  uint8_t revision;
+  uint8_t prog_interface;
+  uint8_t subclass;
+  uint8_t class_code;
+  uint8_t cache_line_size;
+  uint8_t latency_timer;
+  uint8_t header_type;
+  uint8_t bist;
+} __attribute__((packed));
+
+void DumpFn(uint64_t fn_start, uint64_t bus, uint64_t dev, uint64_t fun) {
+  PciDeviceHeader* hdr = reinterpret_cast<PciDeviceHeader*>(fn_start);
+  if (hdr->vendor_id == 0xFFFF) {
+    return;
+  }
+  dbgln(
+      "[%u.%u.%u] (Vendor, Device): (%x, %x), (Type, Class, Sub, PIF): (%u, "
+      "%x, %x, %x)",
+      bus, dev, fun, hdr->vendor_id, hdr->device_id, hdr->header_type,
+      hdr->class_code, hdr->subclass, hdr->prog_interface);
+}
+
+void PciDump(uint64_t base, uint64_t size) {
+  for (uint64_t b = 0; b <= 0xFF; b++) {
+    for (uint64_t d = 0; d <= 0x1F; d++) {
+      for (uint64_t f = 0; f < 8; f++) {
+        uint64_t fn_base = base + (b << 20) + (d << 15) + (f << 12);
+        DumpFn(fn_base, b, d, f);
+      }
+    }
+  }
+}
+
+}  // namespace
+
+void DumpPciEDevices() {
+  dbgln("Creating PCI obj");
+  uint64_t vmmo_cap, vmmo_size;
+  check(ZTempPcieConfigObjectCreate(&vmmo_cap, &vmmo_size));
+
+  dbgln("Creating addr space");
+  uint64_t vaddr;
+  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+  dbgln("Addr %x", vaddr);
+
+  dbgln("Dumping PCI");
+  PciDump(vaddr, vmmo_size);
+  dbgln("Done");
+}

sys/yellowstone/hw/pcie.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void DumpPciEDevices();

sys/yellowstone/yellowstone.cpp

@@ -2,12 +2,16 @@
 #include <mammoth/process.h>
 #include <zcall.h>
 
+#include "hw/pcie.h"
+
 uint64_t main() {
   dbgln("Yellowstone Initializing.");
   uint64_t vaddr;
   check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, Z_INIT_BOOT_VMMO, &vaddr));
   check(SpawnProcessFromElfRegion(vaddr));
 
+  DumpPciEDevices();
+
   dbgln("Yellowstone Finished Successfully.");
   return 0;
 }