feat: split syscalls into files, change max process ceiling

kernel/src/Api/Filesystem.hpp

@@ -0,0 +1,75 @@
+/*
+    * Filesystem.hpp
+    * SYS_OPEN, SYS_READ, SYS_GETSIZE, SYS_CLOSE, SYS_READDIR,
+    * SYS_FWRITE, SYS_FCREATE syscalls
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#pragma once
+#include <Fs/Vfs.hpp>
+#include <Sched/Scheduler.hpp>
+#include <Memory/PageFrameAllocator.hpp>
+#include <Memory/HHDM.hpp>
+#include <Memory/Paging.hpp>
+#include <Libraries/Memory.hpp>
+
+namespace Zenith {
+    static int Sys_Open(const char* path) {
+        return Fs::Vfs::VfsOpen(path);
+    }
+
+    static int Sys_Read(int handle, uint8_t* buffer, uint64_t offset, uint64_t size) {
+        return Fs::Vfs::VfsRead(handle, buffer, offset, size);
+    }
+
+    static uint64_t Sys_GetSize(int handle) {
+        return Fs::Vfs::VfsGetSize(handle);
+    }
+
+    static void Sys_Close(int handle) {
+        Fs::Vfs::VfsClose(handle);
+    }
+
+    static int Sys_ReadDir(const char* path, const char** outNames, int maxEntries) {
+        // Get entries from VFS into a kernel-local array
+        const char* kernelNames[64];
+        int max = maxEntries;
+        if (max > 64) max = 64;
+        int count = Fs::Vfs::VfsReadDir(path, kernelNames, max);
+        if (count <= 0) return count;
+
+        // Allocate a user-accessible page for string data via process heap
+        auto* proc = Sched::GetCurrentProcessPtr();
+        if (proc == nullptr) return -1;
+
+        void* page = Memory::g_pfa->AllocateZeroed();
+        if (page == nullptr) return -1;
+        uint64_t physAddr = Memory::SubHHDM((uint64_t)page);
+        uint64_t userVa = proc->heapNext;
+        proc->heapNext += 0x1000;
+        Memory::VMM::Paging::MapUserIn(proc->pml4Phys, physAddr, userVa);
+
+        // Copy strings into the user page and write pointers to outNames
+        uint64_t offset = 0;
+        uint8_t* pageBuf = (uint8_t*)Memory::HHDM(physAddr);
+        int copied = 0;
+        for (int i = 0; i < count; i++) {
+            int len = Lib::strlen(kernelNames[i]) + 1;
+            if (offset + len > 0x1000) break;
+            memcpy(pageBuf + offset, kernelNames[i], len);
+            outNames[i] = (const char*)(userVa + offset);
+            offset += len;
+            copied++;
+        }
+
+        return copied;
+    }
+
+    static int Sys_FWrite(int handle, const uint8_t* data, uint64_t offset, uint64_t size) {
+        return Fs::Vfs::VfsWrite(handle, data, offset, size);
+    }
+
+    static int Sys_FCreate(const char* path) {
+        return Fs::Vfs::VfsCreate(path);
+    }
+};