Expose storedevs to the outside world via dev interface

kernel/randcrypto/randcrypto.c

@@ -0,0 +1,6 @@
+#include "randcrypto.h"
+#include "uniqid.h"
+
+void randcrypto_init(void) {
+  randcrypto_uniqid_init();
+}

kernel/randcrypto/randcrypto.h

@@ -0,0 +1,6 @@
+#ifndef RANDCRYPTO_RANDCRYPTO_H_
+#define RANDCRYPTO_RANDCRYPTO_H_
+
+void randcrypto_init(void);
+
+#endif // RANDCRYPTO_RANDCRYPTO_H_

kernel/randcrypto/uniqid.c

@@ -0,0 +1,51 @@
+#include <stdint.h>
+#include <stddef.h>
+#include "uniqid.h"
+#include "atomic.h"
+#include "spinlock/spinlock.h"
+
+static const char *base62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+static uint32_t uniqstate = 0u;
+SpinLock uniqstate_spinlock;
+
+void randcrypto_uniqid_init(void) {
+  spinlock_init(&uniqstate_spinlock);
+}
+
+uint32_t uniqmix32(uint32_t x) {
+  x ^= x >> 16;
+  x *= 0x85ebca6bU;
+  x ^= x >> 13;
+  x *= 0xc2b2ae35U;
+  x ^= x >> 16;
+  return x;
+}
+
+void randcrypto_gen_uniqid(char *out, size_t n) {
+  if (!out || n == 0) {
+    return;
+  }
+
+  spinlock_acquire(&uniqstate_spinlock);
+
+  if (uniqstate == 0u) {
+    uintptr_t p = (uintptr_t)(void *)&uniqstate;
+    uint32_t seed = (uint32_t)(p ^ (p >> 16));
+    uniqstate = seed ^ 0x9E3779B9u;
+    if (uniqstate == 0u) {
+      uniqstate = 1u;
+    }
+  }
+
+  uniqstate += 0x9E3779B1u;
+  uint32_t v = uniqmix32(uniqstate);
+  
+  spinlock_release(&uniqstate_spinlock);
+
+  for (size_t i = 0; i < n; i++) {
+    v = uniqmix32(v + i * 0x27d4eb2dU);
+    out[i] = base62[v % 62u];
+  }
+  out[n] = '\0';
+}

kernel/randcrypto/uniqid.h

@@ -0,0 +1,10 @@
+#ifndef RANDCRYPTO_UNIQID_H_
+#define RANDCRYPTO_UNIQID_H_
+
+#include <stdint.h>
+#include <stddef.h>
+
+void randcrypto_uniqid_init(void);
+void randcrypto_gen_uniqid(char *out, size_t n);
+
+#endif // RANDCRYPTO_UNIQID_H_