feat: added Files app USB medium detection

kernel/src/Api/Filesystem.hpp

@@ -7,6 +7,8 @@
 
 #pragma once
 #include <Fs/Vfs.hpp>
+#include <Fs/FsProbe.hpp>
+#include <Drivers/Storage/BlockDevice.hpp>
 #include <Sched/Scheduler.hpp>
 #include <Memory/PageFrameAllocator.hpp>
 #include <Memory/HHDM.hpp>
@@ -126,4 +128,11 @@ namespace Montauk {
     static int Sys_DriveLabel(int driveNumber, char* outLabel, int maxLen) {
         return Fs::Vfs::VfsDriveLabel(driveNumber, outLabel, maxLen);
     }
+
+    static int Sys_DriveKind(int driveNumber) {
+        int blockDev = Fs::FsProbe::GetBlockDeviceForDrive(driveNumber);
+        if (blockDev < 0) return 0;
+        auto* dev = Drivers::Storage::GetBlockDevice(blockDev);
+        return dev ? (int)dev->Kind : 0;
+    }
 };

kernel/src/Api/Syscall.cpp

@@ -217,6 +217,8 @@ namespace Montauk {
                 if ((int64_t)frame->arg3 <= 0) return -1;
                 if (!UserMemory::Range(frame->arg2, frame->arg3, true)) return -1;
                 return (int64_t)Sys_DriveLabel((int)frame->arg1, (char*)frame->arg2, (int)frame->arg3);
+            case SYS_DRIVEKIND:
+                return (int64_t)Sys_DriveKind((int)frame->arg1);
             case SYS_TERMSCALE:
                 return Sys_TermScale(frame->arg1, frame->arg2);
             case SYS_RESOLVE:

kernel/src/Api/Syscall.hpp

@@ -225,6 +225,7 @@ namespace Montauk {
 
     /* Filesystem.hpp */
     static constexpr uint64_t SYS_DRIVELABEL          = 124;
+    static constexpr uint64_t SYS_DRIVEKIND           = 127;
 
     /* Net.hpp */
     static constexpr uint64_t SYS_NETSTATUS           = 125;

kernel/src/Fs/FsProbe.cpp

@@ -142,6 +142,18 @@ namespace Fs::FsProbe {
         return -1;
     }
 
+    int GetBlockDeviceForDrive(int driveNum) {
+        if (driveNum < 0) return -1;
+        int partCount = Drivers::Storage::Gpt::GetPartitionCount();
+        for (int i = 0; i < partCount && i < Drivers::Storage::Gpt::MaxPartitions; i++) {
+            if (g_mounted[i] && g_driveForPart[i] == driveNum) {
+                auto* part = Drivers::Storage::Gpt::GetPartition(i);
+                if (part) return part->BlockDevIndex;
+            }
+        }
+        return -1;
+    }
+
     int UnmountPartitionsForBlockDevice(int blockDevIndex) {
         int partCount = Drivers::Storage::Gpt::GetPartitionCount();
         int unmounted = 0;

kernel/src/Fs/FsProbe.hpp

@@ -34,4 +34,8 @@ namespace Fs::FsProbe {
     // mount bookkeeping to match Gpt::RemovePartitionsForBlockDevice().
     int UnmountPartitionsForBlockDevice(int blockDevIndex);
 
+    // Return the block-device index backing a mounted VFS drive, or -1 if the
+    // drive isn't backed by a partition (e.g. ramdisk).
+    int GetBlockDeviceForDrive(int driveNum);
+
 };