feat: split syscalls into files, change max process ceiling

kernel/src/Api/Random.hpp

@@ -0,0 +1,39 @@
+/*
+    * Random.hpp
+    * SYS_GETRANDOM syscall
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#pragma once
+#include <cstdint>
+
+namespace Zenith {
+
+    // ---- Random number generation ----
+    // Uses RDTSC mixed with xorshift64* PRNG for entropy.
+    // RDRAND is intentionally avoided: some firmware disables the RDRAND
+    // hardware unit while CPUID still advertises support (bit 30 of ECX),
+    // causing #UD on real hardware. RDTSC-based entropy is sufficient for
+    // seeding BearSSL's PRNG for TLS session keys.
+
+    static int64_t Sys_GetRandom(uint8_t* buf, uint64_t len) {
+        uint64_t tsc;
+        asm volatile("rdtsc; shl $32, %%rdx; or %%rdx, %%rax" : "=a"(tsc) :: "rdx");
+        uint64_t state = tsc;
+
+        for (uint64_t i = 0; i < len; i += 8) {
+            asm volatile("rdtsc; shl $32, %%rdx; or %%rdx, %%rax" : "=a"(tsc) :: "rdx");
+            state ^= tsc;
+            state ^= state >> 12;
+            state ^= state << 25;
+            state ^= state >> 27;
+            uint64_t val = state * 0x2545F4914F6CDD1DULL;
+
+            uint64_t remaining = len - i;
+            uint64_t toCopy = remaining < 8 ? remaining : 8;
+            for (uint64_t j = 0; j < toCopy; j++)
+                buf[i + j] = (uint8_t)(val >> (j * 8));
+        }
+        return (int64_t)len;
+    }
+};