feat: add 'vol' command

programs/include/Api/Syscall.hpp

@@ -262,6 +262,9 @@ namespace montauk::abi {
     // The caller's own capability masks.
     static constexpr uint64_t SYS_GETCAPS              = 189;  // (SpawnCapabilities*) -> 0, -1 bad pointer
 
+    /* Storage.hpp */
+    static constexpr uint64_t SYS_VOLINFO              = 190;  // (VolInfo*, maxCount) -> count, -1 bad pointer
+
     /* Kernel-owned process capabilities. User identities may namespace
        per-user resources, but never participate in authorization decisions. */
     static constexpr uint64_t CAP_PROCESS_ADMIN = 1ULL << 0;
@@ -603,6 +606,28 @@ namespace montauk::abi {
         char     typeName[24];    // human-readable type name
     };
 
+    // One mounted volume (returned by SYS_VOLINFO). A volume is a single
+    // mounted filesystem, which is what a drive number names: one physical
+    // disk with three partitions occupies three drive numbers.
+    //
+    // A volume with no backing partition -- the boot ramdisk -- reports
+    // blockDev and partIndex as -1 and leaves the geometry fields zero.
+    struct VolInfo {
+        int32_t  drive;           // VFS drive number ("N:/")
+        int32_t  blockDev;        // backing block device index, -1 if none
+        int32_t  partIndex;       // global GPT partition index, -1 if none
+        uint32_t kind;            // BlockDeviceKind: 0=none/ramdisk, 1=SATA, 2=SATAPI, 3=NVMe, 4=USB MSC
+        uint64_t startLba;        // partition start LBA, 0 if none
+        uint64_t sectorCount;     // partition length in sectors, 0 if none
+        uint32_t sectorSize;      // logical sector size in bytes, 0 if none
+        uint32_t _pad0;
+        char     label[36];       // filesystem volume label, "" if unset
+        char     fsType[12];      // "ext2", "FAT32", "ramdisk", "" if unknown
+        char     partName[72];    // GPT partition name, "" if none
+        char     model[41];       // backing disk model, "" if none
+        char     _pad1[3];
+    };
+
     struct GptAddParams {
         int32_t  blockDev;
         uint32_t _pad0;