diff --git a/build.cmd b/build.cmd
index d3ac370..a9ce1f0 100644
--- a/build.cmd
+++ b/build.cmd
@@ -1,9 +1,15 @@
 @echo off
 setlocal enabledelayedexpansion
 
+set PLATFORM=win32
 set CIABATTA_OPTIONS=-Iinc -g -gcodeview -nodefaultlibs -D_CRT_SECURE_NO_WARNINGS
 
-for /R %%F in (*.c) do (
+for /R code %%F in (*.c) do (
+	echo %%F
+	clang -c -o build\%%~nF.obj %%F %CIABATTA_OPTIONS%
+)
+for /R platform\%PLATFORM% %%F in (*.c) do (
+	echo %%F
 	clang -c -o build\%%~nF.obj %%F %CIABATTA_OPTIONS%
 )
 llvm-ar rc ciabatta.lib build\*.obj
diff --git a/code/stdlib/conv.c b/code/stdlib/conv.c
new file mode 100644
index 0000000..f40392d
--- /dev/null
+++ b/code/stdlib/conv.c
@@ -0,0 +1,160 @@
+
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <limits.h>
+#include <errno.h>
+
+// TODO: strto*: locale-based parsing for integers
+// TODO: i made a function that parses longs and i'm fucken
+// tired. someone make float parsing :kekw:
+
+#define inrange(start, c, end) ((start) <= (c) && (c) <= (end))
+
+static bool isbase(int c, int base) {
+    int val;
+    if(isdigit(c)) {
+        val = c-'0';
+    }
+    else if(islower(c)) {
+        val = c-'a'+10;
+    }
+    else if(isupper(c)) {
+        val = c-'A'+10;
+    }
+    else {
+        return false;
+    }
+    return val < base;
+}
+
+// Called only when isbase(c, base) for some base in range
+static long todigitl(int c) {
+    int val;
+    if(isdigit(c)) {
+        val = c-'0';
+    }
+    else if(islower(c)) {
+        val = c-'a'+10;
+    }
+    else if(isupper(c)) {
+        val = c-'A'+10;
+    }
+    return val;
+}
+
+long
+strtol(const char *restrict nptr, char **restrict endptr, int inbase) {
+    if(!inrange(0, inbase, 36)) {
+        *endptr = NULL;
+        return 0;
+    }
+    // Skip space on the beginning
+    while(isspace(*nptr)) {
+        ++nptr;
+    }
+    // Parse sign
+    long coef = 1;
+    if(*nptr == '-') {
+        coef = -1;
+        ++nptr;
+    }
+    if(*nptr == '+') {
+        ++nptr;
+    }
+    unsigned long base = (unsigned long)inbase;
+    unsigned long value = 0;
+    // See if we need to parse base in C-like format
+    if(*nptr == '0' && *(nptr+1) == 'x') {
+        ++nptr;
+        if(base == 16 || base == 0) {
+            ++nptr;
+            base = 16;
+        }
+        else {
+            value = 0;
+            goto end;
+        }
+    }
+    else if(*nptr == '0') {
+        ++nptr;
+        if(base == 8 || base == 0) {
+            base = 8;
+        }
+    }
+    while(isbase(*nptr, (int)base)) {
+        unsigned long digit = (unsigned long)todigitl(*nptr);
+        if(value > (ULONG_MAX - digit)/base) {
+            errno = ERANGE;
+            value = 0;
+            goto end;
+        }
+        value = base*value + digit;
+        ++nptr;
+    }
+    unsigned long max_modulo = (unsigned long)LONG_MAX+1;
+    if(value > max_modulo) {
+        errno = ERANGE;
+        value = 0;
+        goto end;
+    }
+    if(value == max_modulo) {
+        if(coef == 1) {
+            errno = ERANGE;
+            value = 0;
+            goto end;
+        }
+        else {
+            value = LONG_MIN;
+            coef = 1;
+        }
+    }
+end:
+    if(endptr != NULL) {
+        *endptr = (char *)nptr;
+    }
+    return coef*(long)value;
+}
+
+long long
+strtoll(const char *restrict nptr, char **restrict endptr, int base) {
+    return 0;
+}
+
+unsigned long
+strtoul(const char *restrict nptr, char **restrict endptr, int base) {
+    return 0;
+}
+
+unsigned long long
+strtoull(const char *restrict nptr, char **restrict endptr, int base) {
+    return 0;
+}
+
+double atof(const char *nptr) {
+    return strtod(nptr, (char **)NULL);
+}
+
+int atoi(const char *nptr) {
+    return (int)strtol(nptr, (char **)NULL, 10);
+}
+
+long int atol(const char *nptr) {
+    return strtol(nptr, (char **)NULL, 10);
+}
+
+long long int atoll(const char *nptr) {
+    return strtoll(nptr, (char **)NULL, 10);
+}
+
+double strtod(const char *restrict nptr, char **restrict endptr) {
+    return 0;
+}
+
+float strtof(const char *restrict nptr, char **restrict endptr) {
+    return 0;
+}
+
+long double strtold(const char *restrict nptr, char **restrict endptr) {
+    return 0;
+}
diff --git a/code/stdlib/rand.c b/code/stdlib/rand.c
new file mode 100644
index 0000000..f9305a2
--- /dev/null
+++ b/code/stdlib/rand.c
@@ -0,0 +1,18 @@
+
+#include <stddef.h>
+#include <stdlib.h>
+
+// TODO: the code for rand/srand was shamelessly copied
+// from C11 standard's example and is a simple LCG.
+// gotta implement a better random function, or no idc
+
+static int last_random_number;
+
+int rand(void) {
+    last_random_number = last_random_number * 1103515245 + 12345;
+    return (unsigned int)(last_random_number/65536) % RAND_MAX;
+}
+
+void srand(unsigned int seed) {
+    last_random_number = seed;
+}
diff --git a/inc/_platform.h b/inc/_platform.h
index ad2ab2a..a0742a0 100644
--- a/inc/_platform.h
+++ b/inc/_platform.h
@@ -51,3 +51,4 @@
 	typedef int errno_t;
 	typedef size_t rsize_t;
 #endif
+
diff --git a/inc/errno.h b/inc/errno.h
index a294129..a1783de 100644
--- a/inc/errno.h
+++ b/inc/errno.h
@@ -4,5 +4,5 @@
 #define EILSEQ 2
 #define ERANGE 3
 
-// TODO:
-//_Thread_local int errno;
+// TODO: make it thread-local
+int errno;
diff --git a/inc/stdlib.h b/inc/stdlib.h
index 9f4bb3b..97d960d 100644
--- a/inc/stdlib.h
+++ b/inc/stdlib.h
@@ -1,4 +1,9 @@
-#include "_platform.h"
+
+#pragma once
+
+#if !defined(NULL)
+#define NULL ((void *)0)
+#endif
 
 // typedef struct div_t {
 //     int quot;
@@ -18,27 +23,31 @@
 // #define EXIT_FAILURE 1
 // #define EXIT_SUCCESS 0
 
-// #define RAND_MAX 65536
+#define RAND_MAX 65536
 // #define MB_CUR_MAX 5
-	
-// double atof(const char *nptr);
-// int atoi(const char *nptr);
-// long int atol(const char *nptr);
-// long long int atoll(const char *nptr);
-// double strtod(const char * restrict nptr, char ** restrict endptr);
-// float strtof(const char * restrict nptr, char ** restrict endptr);
-// long double strtold(const char * restrict nptr, char ** restrict endptr);
-// long int strtol(const char * restrict nptr, char ** restrict endptr, int base);
-// long long int strtoll(const char * restrict nptr, char ** restrict endptr, int base);
-// unsigned long int strtoul(const char * restrict nptr, char ** restrict endptr, int base);
-// unsigned long long int strtoull(const char * restrict nptr, char ** restrict endptr, int base);
-// int rand(void);
-// void srand(unsigned int seed);
-// void *aligned_alloc(size_t alignment, size_t size);
-// void *calloc(size_t nmemb, size_t size);
-// void free(void *ptr);
-// void *malloc(size_t size);
-// void *realloc(void *ptr, size_t size);
+
+double atof(const char *nptr);
+int atoi(const char *nptr);
+long int atol(const char *nptr);
+long long int atoll(const char *nptr);
+double strtod(const char * restrict nptr, char ** restrict endptr);
+float strtof(const char * restrict nptr, char ** restrict endptr);
+long double strtold(const char * restrict nptr, char ** restrict endptr);
+long int strtol(const char *restrict nptr, char **restrict endptr, int base);
+long long int strtoll(const char *restrict nptr, char **restrict endptr, int base);
+unsigned long int strtoul(const char *restrict nptr, char **restrict endptr, int base);
+unsigned long long int strtoull(const char *restrict nptr, char **restrict endptr, int base);
+int rand(void);
+void srand(unsigned int seed);
+
+typedef struct _os_heap _os_heap;
+void _heap_setup(_os_heap *heap);
+void *aligned_alloc(size_t alignment, size_t size);
+void *calloc(size_t nmemb, size_t size);
+void free(void *ptr);
+void *malloc(size_t size);
+void *realloc(void *ptr, size_t size);
+
 // _Noreturn void abort(void);
 // int atexit(void (*func)(void));
 // int at_quick_exit(void (*func)(void));
diff --git a/code/entry_windows.c b/platform/win32/entry.c
similarity index 85%
rename from code/entry_windows.c
rename to platform/win32/entry.c
index a4ae96e..447cb88 100644
--- a/code/entry_windows.c
+++ b/platform/win32/entry.c
@@ -1,9 +1,9 @@
-#include <_platform.h>
+
 #include <locale.h>
 #include <stdbool.h>
+#include <stdlib.h>
 
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
+#include "win32.h"
 
 extern int main(int argc, char** argv);
 
@@ -58,8 +58,18 @@ void mainCRTStartup() {
         convert_wide_chars_to_ansi(args[i], args_wide[i], wide_len);
     }
 
+    _os_heap heap_data = {
+        .handle = heap,
+    };
+    _heap_setup(&heap_data);
+
+    srand(0);
     setlocale(LC_ALL, "C");
     int exit_code = main(arg_count, args);
 
     ExitProcess(exit_code);
 }
+
+// This symbol is required to be present if we're using floating-point
+// numbers
+int _fltused=0;
diff --git a/platform/win32/memory.c b/platform/win32/memory.c
new file mode 100644
index 0000000..746c706
--- /dev/null
+++ b/platform/win32/memory.c
@@ -0,0 +1,74 @@
+
+#include <stdlib.h>
+#include <limits.h>
+#include <stdbool.h>
+
+#include "win32.h"
+
+// TODO: lock the heap before allocation (?)
+
+HANDLE _heap;
+
+static bool is_power_of_two(size_t s) {
+    return (s & (s-1)) == 0;
+}
+
+static intptr_t align_forward(intptr_t p, size_t a) {
+    return (p+a-1)&~(a-1);
+}
+
+void _heap_setup(_os_heap *heap) {
+    _heap = heap->handle;
+}
+
+void *aligned_alloc(size_t alignment, size_t size) {
+    if(size == 0) {
+        return NULL;
+    }
+    if(alignment == 0) {
+        alignment = 8;
+    }
+    if(!is_power_of_two(alignment)) {
+        return NULL;
+    }
+    // HeapAlloc is guaranteed to return 8-byte aligned pointer,
+    // so if our alignment is 8 or less we don't have to overallocate.
+    // otherwise we'll reserve extra `alignment` bytes to later adjust our
+    // memory buffer according to required alignment.
+    size_t min_req_size = size;
+    if(alignment > 8) {
+        min_req_size += alignment;
+    }
+    void *block_start = HeapAlloc(_heap, HEAP_ZERO_MEMORY, size+alignment);
+    intptr_t block_start_i = (intptr_t)block_start;
+    intptr_t aligned_block_start_i = align_forward(block_start_i, alignment);
+    void *aligned_block_start = (void *)aligned_block_start_i;
+    return aligned_block_start;
+}
+
+void *calloc(size_t nmemb, size_t size) {
+    if(nmemb == 0 || size == 0) {
+        return NULL;
+    }
+    if(nmemb > SIZE_MAX/size) {
+        return NULL;
+    }
+    void *block_start = HeapAlloc(_heap, HEAP_ZERO_MEMORY, size*nmemb);
+    return block_start;
+}
+
+void free(void *ptr) {
+    if(ptr == NULL) {
+        return;
+    }
+    HeapFree(_heap, 0, ptr);
+}
+
+void *malloc(size_t size) {
+    return aligned_alloc(8, size);
+}
+
+void *realloc(void *ptr, size_t size) {
+    void *buffer = HeapReAlloc(_heap, 0, ptr, size);
+    return buffer;
+}
diff --git a/platform/win32/win32.h b/platform/win32/win32.h
new file mode 100644
index 0000000..1cebe50
--- /dev/null
+++ b/platform/win32/win32.h
@@ -0,0 +1,9 @@
+
+#pragma once
+
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+
+struct _os_heap {
+    HANDLE handle;
+};