major backup 8.24.21

1 files changed, 36 insertions, 0 deletions

diff --git a/src/kernel/random.c b/src/kernel/random.c
new file mode 100644
index 0000000..404223a
--- /dev/null
+++ b/src/kernel/random.c
@@ -0,0 +1,36 @@
+#include <stdbool.h>
+#include <cpuid.h>
+#include <printf.h>
+#include <stdint.h>
+
+static bool hw_random = false;
+static unsigned long int seed = -1;
+
+void randinit() {
+  unsigned int unused, eax, ecx;
+  eax = 0;
+  ecx = 0;
+  __get_cpuid(1, &eax, &unused, &ecx, &unused); 
+  hw_random = (ecx >> 30) & 1;
+  printf("Kernel random source: %s.\n", (hw_random) ? "rdrand" : "pseudo");
+}
+
+//As of now, this function isn't nessesarily meant to be fast.
+unsigned int randint() {
+  uint64_t random_long = 0;
+  if(hw_random) {
+    asm("rand:\n"
+        "rdrand %0\n"
+        "jc finished\n"
+        "pause\n"
+        "jmp rand\n"
+        "finished:" :"=r"(random_long)::"rax" );
+  }
+  else {
+    //TODO FUCKING ENTROPY!!!!!!!111
+    seed = 1103515245 * seed + 12345;
+    return(unsigned int)(seed / 65536) % 32768;
+  }
+  return 0;
+}
+