maybe fix colors in kmalloc

improve type clarity

kernel/include/errno.h

@@ -13,23 +13,24 @@
 // TODO: Add correct errno.h numbers
 enum {
 	SUCCESS = 0,
-	ENOMEM,		// Cannot allocate memory
-	EPERM,		// Operation not permitted
-	ENOENT,		// No entry (no such file or directory)
-	EIO,		// Input/Output error
-	ENXIO,		// No such device or address
-	EAGAIN,		// Resource temporarly busy
-	EACCES,		// Permission denied
-	EFAULT,		// Bad address
-	ENODEV,		// No such device
-	EINVAL,		// Invalid argument
-	EDOM,		// Numerical argument out of domain
-	ERANGE,		// Numerical result out of range
-	ENOSYS,		// Function not implemented
-	ENOTSUP,	// Not supported
-	EILLSEQ,	// Illegal byte sequence
-	EOVERFLOW,	// 
-	EALIGN,		// Not aligned
+	ENOMEM,	   // Cannot allocate memory
+	EPERM,	   // Operation not permitted
+	ENOENT,	   // No entry (no such file or directory)
+	EIO,	   // Input/Output error
+	ENXIO,	   // No such device or address
+	EAGAIN,	   // Resource temporarly busy
+	EACCES,	   // Permission denied
+	EFAULT,	   // Bad address
+	ENODEV,	   // No such device
+	EINVAL,	   // Invalid argument
+	EDOM,	   // Numerical argument out of domain
+	ERANGE,	   // Numerical result out of range
+	ENOSYS,	   // Function not implemented
+	ENOTSUP,   // Not supported
+	EILLSEQ,   // Illegal byte sequence
+	EOVERFLOW, //
+	EALIGN,	   // Not aligned
+	EEXIST,	   // already exists
 };
 
 #endif

kernel/include/kmalloc.h

@@ -19,45 +19,54 @@ void* kcalloc(size_t count, size_t size);
 #define KMALLOC_MAX_SIZE 17
 #define LOWEST_POWER 3
 
-union per_cpu_freelist_cache {
-	void** freelists[KMALLOC_MAX_SIZE];
+struct freelist {
+	struct freelist* nextnode;
+};
+
+struct partialy_freelist {
+	struct freelist* freelist_nextnode;
+	struct partialy_freelist* partialy_freelist_nextnode;
+};
+
+union freelists_list {
+	struct freelist* freelists[KMALLOC_MAX_SIZE];
 	struct {
-		void** kmalloc_8;
-		void** kmalloc_16;
-		void** kmalloc_32;
-		void** kmalloc_64;
-		void** kmalloc_128;
-		void** kmalloc_256;
-		void** kmalloc_512;
-		void** kmalloc_1024;
-		void** kmalloc_2048;
-		void** kmalloc_4096;
-		void** kmalloc_8192;
-		void** kmalloc_16384;
-		void** kmalloc_32768;
-		void** kmalloc_65536;
-		void** kmalloc_131072;
+		struct freelist* kmalloc_8;
+		struct freelist* kmalloc_16;
+		struct freelist* kmalloc_32;
+		struct freelist* kmalloc_64;
+		struct freelist* kmalloc_128;
+		struct freelist* kmalloc_256;
+		struct freelist* kmalloc_512;
+		struct freelist* kmalloc_1024;
+		struct freelist* kmalloc_2048;
+		struct freelist* kmalloc_4096;
+		struct freelist* kmalloc_8192;
+		struct freelist* kmalloc_16384;
+		struct freelist* kmalloc_32768;
+		struct freelist* kmalloc_65536;
+		struct freelist* kmalloc_131072;
 	};
 };
 
-union partial_list {
-	void** freelists[KMALLOC_MAX_SIZE];
+union partialy_freelists_list {
+	struct partialy_freelist* partialy_freelists[KMALLOC_MAX_SIZE];
 	struct {
-		void** kmalloc_8;
-		void** kmalloc_16;
-		void** kmalloc_32;
-		void** kmalloc_64;
-		void** kmalloc_128;
-		void** kmalloc_256;
-		void** kmalloc_512;
-		void** kmalloc_1024;
-		void** kmalloc_2048;
-		void** kmalloc_4096;
-		void** kmalloc_8192;
-		void** kmalloc_16384;
-		void** kmalloc_32768;
-		void** kmalloc_65536;
-		void** kmalloc_131072;
+		struct partialy_freelist* kmalloc_8;
+		struct partialy_freelist* kmalloc_16;
+		struct partialy_freelist* kmalloc_32;
+		struct partialy_freelist* kmalloc_64;
+		struct partialy_freelist* kmalloc_128;
+		struct partialy_freelist* kmalloc_256;
+		struct partialy_freelist* kmalloc_512;
+		struct partialy_freelist* kmalloc_1024;
+		struct partialy_freelist* kmalloc_2048;
+		struct partialy_freelist* kmalloc_4096;
+		struct partialy_freelist* kmalloc_8192;
+		struct partialy_freelist* kmalloc_16384;
+		struct partialy_freelist* kmalloc_32768;
+		struct partialy_freelist* kmalloc_65536;
+		struct partialy_freelist* kmalloc_131072;
 	};
 };
 

kernel/include/limits.h

@@ -1,5 +1,31 @@
 #ifndef _LIMIT_H
 #define _LIMIT_H
+
 #define CHAR_BIT 8
 
-#endif
+#define INT8_WIDTH 8
+#define INT16_WIDTH 16
+#define INT32_WIDTH 32
+#define INT64_WIDTH 64
+
+#define UINT8_WIDTH 8
+#define UINT16_WIDTH 16
+#define UINT32_WIDTH 32
+#define UINT64_WIDTH 64
+
+#define INT8_MAX 127
+#define INT16_MAX 32767
+#define INT32_MAX 2147483647
+#define INT64_MAX 9223372036854775807LL
+
+#define INT8_MIN (-128)
+#define INT16_MIN (-32768)
+#define INT32_MIN (-2147483647 - 1)
+#define INT64_MIN (-9223372036854775807LL - 1LL)
+
+#define UINT8_MAX 255U
+#define UINT16_MAX 65535U
+#define UINT32_MAX 4294967295U
+#define UINT64_MAX 18446744073709551615ULL
+
+#endif

kernel/include/random.h

@@ -0,0 +1,8 @@
+#ifndef _RANDOM_H
+#define _RANDOM_H
+
+#include <types.h>
+void rand_init();
+
+extern uint64_t (*get_random_number)();
+#endif

kernel/src/kmain.c

@@ -2,6 +2,7 @@
 #include <kernel.h>
 #include <paging.h>
 #include <serial.h>
+#include <random.h>
 #include <splash.h>
 #include <system.h>
 #include <gdt.h>
@@ -32,6 +33,15 @@ void _start(void) {
 	if ((err = pmm_init()) < 0) panic(NULL, "Failed to initalize Physical Memory Manager. (%d)", err);
 	if ((err = pag_init()) < 0) panic(NULL, "Failed to initalize Paging. (%d)", err);
 
+	// random number generation
+	rand_init();
+	// test random number generation
+	printk("Random number generation test:\n");
+	for (uint8_t i = 0; i <= 16; i++) {
+		printk("%d: %lu\n",i,get_random_number());
+	}
+
+
 	// The most important function in the world.
 	splash();
 

kernel/src/kmalloc.c

@@ -6,7 +6,8 @@
 // this file contains SLUB inspired HEAP allocator
 
 // TODO this will be an allocated array later when we have APIC MADT
-union per_cpu_freelist_cache freelists_all_cpus[1];
+union freelists_list freelists_all_cpus[1];
+union partialy_freelists_list partial_free_lists[1];
 
 void* kcalloc(size_t count, size_t size) {
 	size_t size_to_alloc;
@@ -54,26 +55,76 @@ void* kmalloc(size_t size) {
 	size_t alloc_index;
 	{
 		uint8_t leading_zeros = __builtin_clzll(size);
-		if (__builtin_popcountll(size) == 1) {
+		if (/*__builtin_popcountll(size) == */1) {
 			alloc_index = leading_zeros;
 		} else {
 			alloc_index = sizeof(size) * CHAR_BIT - leading_zeros;
 		}
 		if (alloc_index > KMALLOC_MAX_SIZE) {
 			// NOT IMPLEMENTED
-			printk("Cannot allocate [%lu] bytes: \e[1MNOT "
-			       "IMPLEMENTED!\e[8M\n",
+			printk("Cannot allocate [%lu] bytes: \e[1mNOT "
+			       "IMPLEMENTED!\e[0m\n",
 			       size);
 			return NULL;
 		}
 		alloc_index -= LOWEST_POWER;
 	}
-	void** selected_freelist =
+	struct freelist* selected_freelist =
 	    freelists_all_cpus[core_id].freelists[alloc_index];
 	if (selected_freelist != NULL) {
 		// fast path
-		void** second_item_in_list = *selected_freelist;
+		if (selected_freelist->nextnode == NULL) {
+			freelists_all_cpus[core_id].freelists[alloc_index] =
+			    NULL;
+		} else {
+			freelists_all_cpus[core_id].freelists[alloc_index] =
+			    selected_freelist->nextnode;
+		}
+		return selected_freelist;
+
 	} else {
 		// slower path
+		if (partial_free_lists[core_id]
+			.partialy_freelists[alloc_index] != NULL) {
+			// partialy freelist available
+			struct partialy_freelist* selected_partialy_freelist =
+			    partial_free_lists[core_id]
+				.partialy_freelists[alloc_index];
+
+			if (selected_partialy_freelist->freelist_nextnode ==
+			    NULL) {
+				// only one free object available
+				if (selected_partialy_freelist
+					->partialy_freelist_nextnode != NULL) {
+					// next partialy free list available
+					partial_free_lists[core_id]
+					    .partialy_freelists[alloc_index] =
+					    selected_partialy_freelist
+						->partialy_freelist_nextnode;
+
+				} else {
+					// no other partialy free list available
+					partial_free_lists[core_id]
+					    .partialy_freelists[alloc_index] =
+					    NULL;
+				}
+
+			} else {
+				// multiple free objects available
+				partial_free_lists[core_id]
+				    .partialy_freelists[alloc_index] =
+				    selected_partialy_freelist
+					->partialy_freelist_nextnode;
+
+				freelists_all_cpus[core_id]
+				    .freelists[alloc_index] =
+				    selected_partialy_freelist
+					->freelist_nextnode;
+			}
+			return selected_partialy_freelist;
+
+		} else {
+			// slowest path
+		}
 	}
 }

kernel/src/random.c

@@ -0,0 +1,52 @@
+#include "kernel.h"
+#include <system.h>
+#include <types.h>
+
+uint64_t (*get_random_number)();
+
+// this starting value it truly random i have thrown a dice few times
+uint64_t LFSR = 61113534451;
+
+// RDSEED may be backdoored by NSA
+extern uint64_t rand_rdrand();
+asm(".intel_syntax noprefix\n"
+    ".global rand_rdrand\n"
+    "rand_rdrand:"
+    "   rdrand rax\n"
+    "   ret\n"
+    ".att_syntax prefix\n");
+
+uint64_t rand_software() {
+	uint64_t lsb = LFSR & 1;
+	LFSR >>= 1;
+	if (lsb) {
+		LFSR ^= 0x800000000000000DULL;
+	}
+	return LFSR;
+}
+
+void rand_init() {
+	uint32_t eax = 1, ebx = 0, ecx = 0, edx = 0;
+	cpuid(&eax, &ebx, &ecx, &edx);
+
+	// check for RDRAND
+	if ((ecx >> 30) & 1) {
+		get_random_number = rand_rdrand;
+	} else {
+		printk("[\e[33mWARNING\e[0m] RDRAND not available falling back "
+		       "to software\n");
+		// check for RDSEED
+		if ((ebx >> 18) & 1) {
+			asm(".intel_syntax noprefix\n"
+			    "rdseed %0\n"
+			    ".att_syntax prefix\n"
+			    : "=r"(LFSR));
+		} else {
+			printk("[\e[\e[33mWARNING\e[0m] RDSEED not available "
+			       "falling back "
+			       "to developers dice trows\n");
+		}
+		get_random_number = rand_software;
+	}
+    printk("[\e[32mINFO\e[0m] RNG initialized!\n");
+}

kernel/src/vmm.c

@@ -0,0 +1,49 @@
+#include "kernel.h"
+#include <errno.h>
+#include <isr.h>
+#include <limits.h>
+#include <paging.h>
+#include <pmm.h>
+#include <types.h>
+
+// allocates set number of pages at address provided
+// if address is NULL address is chosen internaly
+int vmm_alloc(void** vaddr, uint64_t count, uint64_t flags) {
+	if (flags == 0) {
+		flags = PTE_FLAG_PRESENT | PTE_FLAG_WRITE | PTE_FLAG_NOEXEC;
+	}
+
+	uint64_t* pml4 = pag_get_pml4();
+	for (uint64_t i = 0; i < count; i++) {
+		uint64_t* pte = pag_get_pte(pml4, vaddr);
+		if (!IS_ERR(pte) && (*pte & PTE_FLAG_PRESENT)) {
+			// TODO actualy handle conflict
+			return EEXIST;
+		}
+	}
+
+	for (uint64_t i = 0; i < count; i++) {
+		void* paddr = pmm_alloc();
+		int pag_map_ret =
+		    pag_map(pml4, (void*)(((size_t)vaddr) * i * PAGE_SIZE),
+			    paddr, flags);
+		if (pag_map_ret != SUCCESS) {
+			if (i != 0) {
+				for (i -= 1; i != UINT64_MAX; i--) {
+					if (pag_unmap(pml4,
+						      (void*)(((size_t)vaddr) *
+							      i * PAGE_SIZE)) !=
+					    SUCCESS) {
+						panic(NULL,
+						      "failed to unmap "
+						      "previously mapped "
+						      "page. %s:%d",
+						      __FILE_NAME__, __LINE__);
+					}
+				}
+			}
+			return pag_map_ret;
+		}
+	}
+	return SUCCESS;
+}