Kernel/PCI: Expose PCI option ROM data from the sysfs interface

For each exposed PCI device in sysfs, there's a new node called "rom"
and by reading it, it exposes the raw data of a PCI option ROM blob to
a user for examining the blob.

2 files changed, 15 insertions, 0 deletions

diff --git a/Kernel/Bus/PCI/API.cpp b/Kernel/Bus/PCI/API.cpp
index 5ea9b5245a..ff4602acd4 100644
--- a/Kernel/Bus/PCI/API.cpp
+++ b/Kernel/Bus/PCI/API.cpp
@@ -232,6 +232,19 @@ size_t get_BAR_space_size(DeviceIdentifier const& identifier, HeaderType0BaseReg
     return space_size;
 }
 
+size_t get_expansion_rom_space_size(DeviceIdentifier const& identifier)
+{
+    SpinlockLocker locker(identifier.operation_lock());
+    u8 field = to_underlying(PCI::RegisterOffset::EXPANSION_ROM_POINTER);
+    u32 bar_reserved = read32_offsetted(identifier, field);
+    write32_offsetted(identifier, field, 0xFFFFFFFF);
+    u32 space_size = read32_offsetted(identifier, field);
+    write32_offsetted(identifier, field, bar_reserved);
+    space_size &= 0xfffffff0;
+    space_size = (~space_size) + 1;
+    return space_size;
+}
+
 void raw_access(DeviceIdentifier const& identifier, u32 field, size_t access_size, u32 value)
 {
     SpinlockLocker locker(identifier.operation_lock());
diff --git a/Kernel/Bus/PCI/API.h b/Kernel/Bus/PCI/API.h
index 1b7c641c2e..5f9a62ade3 100644
--- a/Kernel/Bus/PCI/API.h
+++ b/Kernel/Bus/PCI/API.h
@@ -35,6 +35,8 @@ u32 get_BAR5(DeviceIdentifier const&);
 u32 get_BAR(DeviceIdentifier const&, HeaderType0BaseRegister);
 size_t get_BAR_space_size(DeviceIdentifier const&, HeaderType0BaseRegister);
 BARSpaceType get_BAR_space_type(u32 pci_bar_value);
+size_t get_expansion_rom_space_size(DeviceIdentifier const&);
+
 void enable_bus_mastering(DeviceIdentifier const&);
 void disable_bus_mastering(DeviceIdentifier const&);
 void enable_io_space(DeviceIdentifier const&);