Some syscalls and userspace stuff

sorry for the worse-getting commit messages...

14 files changed, 587 insertions, 34 deletions

diff --git a/src/kernel/graphics/vesa.c b/src/kernel/graphics/vesa.c
index 1b759e4..d673bde 100644
--- a/src/kernel/graphics/vesa.c
+++ b/src/kernel/graphics/vesa.c
@@ -194,6 +194,9 @@ void set_optimal_resolution()
         paging_map((uint32_t) fb + z, (uint32_t) fb + z, PT_PRESENT | PT_RW | PT_USED);
         paging_map((uint32_t) cursor_buffer + z, (uint32_t) cursor_buffer + z, PT_PRESENT | PT_RW | PT_USED);
     }
+    paging_set_user((uint32_t) fb, fb_size);
+    serial_write_hex((int) &fb);
+    serial_write("\n");
 
     if (vbe_height > 1440) vesa_set_font(32);
     else if (vbe_height > 720) vesa_set_font(24);
diff --git a/src/kernel/lib/stdlib/liballoc.c b/src/kernel/lib/stdlib/liballoc.c
index 41c55e1..04dc450 100644
--- a/src/kernel/lib/stdlib/liballoc.c
+++ b/src/kernel/lib/stdlib/liballoc.c
@@ -454,4 +454,4 @@ void *PREFIX(realloc)(void *p, size_t size)
     PREFIX(free)(p);
 
     return ptr;
-}
+}
\ No newline at end of file
diff --git a/src/kernel/net/rtl8139.c b/src/kernel/net/rtl8139.c
index a233004..de68700 100644
--- a/src/kernel/net/rtl8139.c
+++ b/src/kernel/net/rtl8139.c
@@ -59,7 +59,7 @@ int rtl8139_init(void)
         // Get mac address
         for (int i = 0; i < 6; ++i)
             mac[i] = inb(rtl_iobase + 0x00 + i);
-        info("Mac address: %2x:%2x:%2x:%2x:%2x:%2x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+        debug("Mac address: %2x:%2x:%2x:%2x:%2x:%2x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 
         // Activate (turn on)
         outb(rtl_iobase + 0x52, 0x0);
diff --git a/src/kernel/syscall/actions/sys_paging_alloc.c b/src/kernel/syscall/actions/sys_paging_alloc.c
new file mode 100644
index 0000000..fb4e415
--- /dev/null
+++ b/src/kernel/syscall/actions/sys_paging_alloc.c
@@ -0,0 +1,10 @@
+#include <stdint.h>
+#include <kernel/paging/paging.h>
+#include <kernel/io/io.h>
+
+uint32_t sys_paging_alloc(uint32_t count)
+{
+    uint32_t ptr = paging_alloc_pages((uint32_t) count);
+    paging_set_user(ptr, count);
+    return ptr;
+}
\ No newline at end of file
diff --git a/src/kernel/syscall/actions/sys_paging_free.c b/src/kernel/syscall/actions/sys_paging_free.c
new file mode 100644
index 0000000..cdf7bb1
--- /dev/null
+++ b/src/kernel/syscall/actions/sys_paging_free.c
@@ -0,0 +1,8 @@
+#include <stdint.h>
+#include <kernel/paging/paging.h>
+
+uint32_t sys_paging_free(uint32_t virt, uint32_t count)
+{
+    paging_set_free(virt, count);
+    return count;
+}
\ No newline at end of file
diff --git a/src/kernel/syscall/actions/sys_read.c b/src/kernel/syscall/actions/sys_read.c
index f04f3ef..02960f6 100644
--- a/src/kernel/syscall/actions/sys_read.c
+++ b/src/kernel/syscall/actions/sys_read.c
@@ -3,6 +3,7 @@
 #include <kernel/input/input.h>
 #include <kernel/lib/lib.h>
 #include <kernel/lib/string.h>
+#include <kernel/io/io.h>
 
 uint32_t sys_read(char *buf)
 {
@@ -15,7 +16,10 @@ uint32_t sys_read(char *buf)
     return strlen(buf);
 }
 
-uint32_t sys_readc()
+uint32_t sys_readc(char *ch)
 {
-    return getch();
+    char buf = getch();
+    ch = &buf;
+    serial_put(*ch);
+    return (uint32_t) ch;
 }
\ No newline at end of file
diff --git a/src/kernel/syscall/actions/sys_write.c b/src/kernel/syscall/actions/sys_write.c
index 554ac5f..8531e85 100644
--- a/src/kernel/syscall/actions/sys_write.c
+++ b/src/kernel/syscall/actions/sys_write.c
@@ -9,12 +9,10 @@ uint32_t sys_write(char *buf)
     return strlen((const char *) buf);
 }
 
-uint32_t sys_writec(char ch)
+uint32_t sys_writec(char *ch)
 {
-    serial_write_hex(ch);
-    serial_write("\n");
-    serial_put(ch);
+    serial_write_hex(*ch);
     serial_write("\n\n");
-    writec(ch);
+    writec((char) *ch);
     return 0;
 }
\ No newline at end of file
diff --git a/src/kernel/syscall/syscall.c b/src/kernel/syscall/syscall.c
index 89b70eb..3a1b011 100644
--- a/src/kernel/syscall/syscall.c
+++ b/src/kernel/syscall/syscall.c
@@ -2,14 +2,19 @@
 #include <kernel/syscall/syscall.h>
 #include <kernel/interrupts/interrupts.h>
 #include <kernel/io/io.h>
+#include <kernel/paging/paging.h>
+#include <kernel/system.h>
 
 typedef uint32_t (*syscall_func)(unsigned int, ...);
 
 uint32_t (*syscalls[])() = {
+        [0] = (uint32_t (*)()) halt_loop, // DEBUG!
         [1] = sys_write,
         [2] = sys_read,
-        [3] = (uint32_t (*)()) sys_writec,
-        [4] = sys_readc
+        [3] = sys_writec,
+        [4] = sys_readc,
+        [5] = sys_paging_alloc,
+        [6] = sys_paging_free
 };
 
 void syscall_handler(struct regs *r)
diff --git a/src/kernel/syscall/syscall.h b/src/kernel/syscall/syscall.h
index 046d702..a037d7f 100644
--- a/src/kernel/syscall/syscall.h
+++ b/src/kernel/syscall/syscall.h
@@ -7,10 +7,14 @@ void syscalls_install();
 
 uint32_t sys_write(char *buf);
 
-uint32_t sys_writec(char ch);
+uint32_t sys_writec(char *ch);
 
 uint32_t sys_read(char *buf);
 
-uint32_t sys_readc();
+uint32_t sys_readc(char *ch);
+
+uint32_t sys_paging_alloc(uint32_t count);
+
+uint32_t sys_paging_free(uint32_t virt, uint32_t count);
 
 #endif
\ No newline at end of file
diff --git a/src/userspace/main.c b/src/userspace/main.c
index 64077eb..4e036c5 100644
--- a/src/userspace/main.c
+++ b/src/userspace/main.c
@@ -1,12 +1,43 @@
 #include <syscall.h>
 
+char *fb;
+int vbe_bpl = 3;
+int vbe_pitch = 3000;
+int vbe_height = 1080;
+int vbe_width = 2560;
+
+void vesa_draw_rectangle(int x1, int y1, int x2, int y2, const uint32_t color[3])
+{
+    int pos1 = x1 * vbe_bpl + y1 * vbe_pitch;
+    char *draw = (char *) &fb[pos1];
+    for (int i = 0; i <= y2 - y1; i++) {
+        for (int j = 0; j <= x2 - x1; j++) {
+            draw[vbe_bpl * j] = color[2];
+            draw[vbe_bpl * j + 1] = color[1];
+            draw[vbe_bpl * j + 2] = color[0];
+        }
+        draw += vbe_pitch;
+    }
+}
+
+void vesa_clear()
+{
+    vesa_draw_rectangle(0, 0, vbe_width - 1, vbe_height - 1, 0);
+}
+
 void user_main()
 {
     char hello[] = "> Successfully switched to usermode!\n";
     syscall_write(hello);
 
-    while (1) {
-        char ch = (char) syscall_readc();
-        syscall_writec(ch);
-    };
+    // fb = (char *) 0x110048;
+    // vesa_clear();
+
+    while (1) {};
+
+    /*while (1) {
+        char *key = malloc(1);
+        syscall_readc(key);
+        syscall_writec(key);
+    };*/
 }
\ No newline at end of file
diff --git a/src/userspace/mlibc/stdlib/liballoc.c b/src/userspace/mlibc/stdlib/liballoc.c
new file mode 100644
index 0000000..ceb87f6
--- /dev/null
+++ b/src/userspace/mlibc/stdlib/liballoc.c
@@ -0,0 +1,454 @@
+#include <stddef.h>
+#include <stdint.h>
+#include <syscall.h>
+
+int liballoc_lock()
+{
+    return 0;
+}
+
+int liballoc_unlock()
+{
+    return 0;
+}
+
+void *liballoc_alloc(size_t p)
+{
+    uint32_t ptr = syscall_paging_alloc((uint32_t) p);
+    return (void *) ptr;
+}
+
+int liballoc_free(void *ptr, size_t p)
+{
+    syscall_paging_free((uint32_t) ptr, (uint32_t) p);
+    return 0;
+}
+
+#define ALIGNMENT 16ul
+#define ALIGN_TYPE char
+#define ALIGN_INFO sizeof(ALIGN_TYPE) * 16
+#define USE_CASE1
+#define USE_CASE2
+#define USE_CASE3
+#define USE_CASE4
+#define USE_CASE5
+
+#define ALIGN(ptr) \
+        if ( ALIGNMENT > 1 ) { \
+            uintptr_t diff; \
+            ptr = (void*) ((uintptr_t) ptr + ALIGN_INFO); \
+            diff = (uintptr_t) ptr & (ALIGNMENT - 1); \
+            if (diff != 0) { \
+                diff = ALIGNMENT - diff; \
+                ptr = (void*) ((uintptr_t) ptr + diff); \
+            } \
+            *((ALIGN_TYPE*) ((uintptr_t) ptr - ALIGN_INFO)) = diff + ALIGN_INFO; \
+        }
+
+#define UNALIGN(ptr) \
+        if (ALIGNMENT > 1) { \
+            uintptr_t diff = *((ALIGN_TYPE*) ((uintptr_t) ptr - ALIGN_INFO)); \
+            if (diff < (ALIGNMENT + ALIGN_INFO)) { \
+                ptr = (void*) ((uintptr_t) ptr - diff); \
+            } \
+        }
+
+#define LIBALLOC_MAGIC 0x900df00d
+#define LIBALLOC_DEAD 0xbaadf00d
+
+struct liballoc_major {
+    struct liballoc_major *prev;
+    struct liballoc_major *next;
+    unsigned int pages;
+    unsigned int size;
+    unsigned int usage;
+    struct liballoc_minor *first;
+};
+
+struct liballoc_minor {
+    struct liballoc_minor *prev;
+    struct liballoc_minor *next;
+    struct liballoc_major *block;
+    unsigned int magic;
+    unsigned int size;
+    unsigned int req_size;
+};
+
+static struct liballoc_major *l_memRoot = NULL;
+static struct liballoc_major *l_bestBet = NULL;
+
+static unsigned int l_pageSize = 4096;
+static unsigned int l_pageCount = 16;
+static unsigned long long l_allocated = 0;
+static unsigned long long l_inuse = 0;
+
+static long long l_warningCount = 0;
+static long long l_errorCount = 0;
+static long long l_possibleOverruns = 0;
+
+static void *liballoc_memset(void *s, int c, size_t n)
+{
+    unsigned int i;
+    for (i = 0; i < n; i++)
+        ((char *) s)[i] = c;
+
+    return s;
+}
+
+static void *liballoc_memcpy(void *s1, const void *s2, size_t n)
+{
+    char *cdest;
+    char *csrc;
+    unsigned int *ldest = (unsigned int *) s1;
+    unsigned int *lsrc = (unsigned int *) s2;
+
+    while (n >= sizeof(unsigned int)) {
+        *ldest++ = *lsrc++;
+        n -= sizeof(unsigned int);
+    }
+
+    cdest = (char *) ldest;
+    csrc = (char *) lsrc;
+
+    while (n > 0) {
+        *cdest++ = *csrc++;
+        n -= 1;
+    }
+    return s1;
+}
+
+static struct liballoc_major *allocate_new_page(unsigned int size)
+{
+    unsigned int st;
+    struct liballoc_major *maj;
+
+    st = size + sizeof(struct liballoc_major);
+    st += sizeof(struct liballoc_minor);
+
+    if ((st % l_pageSize) == 0)
+        st = st / (l_pageSize);
+    else
+        st = st / (l_pageSize) + 1;
+
+    if (st < l_pageCount) st = l_pageCount;
+
+    maj = (struct liballoc_major *) liballoc_alloc(st);
+
+    if (maj == NULL) {
+        l_warningCount += 1;
+        return NULL;
+    }
+
+    maj->prev = NULL;
+    maj->next = NULL;
+    maj->pages = st;
+    maj->size = st * l_pageSize;
+    maj->usage = sizeof(struct liballoc_major);
+    maj->first = NULL;
+
+    l_allocated += maj->size;
+
+    return maj;
+}
+
+void *malloc(size_t req_size)
+{
+    int startedBet = 0;
+    unsigned long long bestSize = 0;
+    void *p = NULL;
+    uintptr_t diff;
+    struct liballoc_major *maj;
+    struct liballoc_minor *min;
+    struct liballoc_minor *new_min;
+    unsigned long size = req_size;
+
+    if (ALIGNMENT > 1) {
+        size += ALIGNMENT + ALIGN_INFO;
+    }
+
+    liballoc_lock();
+
+    if (size == 0) {
+        l_warningCount += 1;
+        liballoc_unlock();
+        // return malloc(1);
+    }
+
+    if (l_memRoot == NULL) {
+        l_memRoot = allocate_new_page(size);
+        if (l_memRoot == NULL) {
+            liballoc_unlock();
+            return NULL;
+        }
+    }
+
+    maj = l_memRoot;
+    startedBet = 0;
+
+    if (l_bestBet != NULL) {
+        bestSize = l_bestBet->size - l_bestBet->usage;
+
+        if (bestSize > (size + sizeof(struct liballoc_minor))) {
+            maj = l_bestBet;
+            startedBet = 1;
+        }
+    }
+
+    while (maj != NULL) {
+        diff = maj->size - maj->usage;
+        if (bestSize < diff) {
+            l_bestBet = maj;
+            bestSize = diff;
+        }
+
+#ifdef USE_CASE1
+        if (diff < (size + sizeof(struct liballoc_minor))) {
+            if (maj->next != NULL) {
+                maj = maj->next;
+                continue;
+            }
+
+            if (startedBet == 1) {
+                maj = l_memRoot;
+                startedBet = 0;
+                continue;
+            }
+
+            maj->next = allocate_new_page(size);
+            if (maj->next == NULL) break;
+            maj->next->prev = maj;
+            maj = maj->next;
+        }
+#endif
+
+#ifdef USE_CASE2
+        if (maj->first == NULL) {
+            maj->first = (struct liballoc_minor *) ((uintptr_t) maj + sizeof(struct liballoc_major));
+
+            maj->first->magic = LIBALLOC_MAGIC;
+            maj->first->prev = NULL;
+            maj->first->next = NULL;
+            maj->first->block = maj;
+            maj->first->size = size;
+            maj->first->req_size = req_size;
+            maj->usage += size + sizeof(struct liballoc_minor);
+            l_inuse += size;
+            p = (void *) ((uintptr_t) (maj->first) + sizeof(struct liballoc_minor));
+            ALIGN(p);
+            liballoc_unlock();
+            return p;
+        }
+#endif
+
+#ifdef USE_CASE3
+        diff = (uintptr_t) (maj->first);
+        diff -= (uintptr_t) maj;
+        diff -= sizeof(struct liballoc_major);
+
+        if (diff >= (size + sizeof(struct liballoc_minor))) {
+            maj->first->prev = (struct liballoc_minor *) ((uintptr_t) maj + sizeof(struct liballoc_major));
+            maj->first->prev->next = maj->first;
+            maj->first = maj->first->prev;
+            maj->first->magic = LIBALLOC_MAGIC;
+            maj->first->prev = NULL;
+            maj->first->block = maj;
+            maj->first->size = size;
+            maj->first->req_size = req_size;
+            maj->usage += size + sizeof(struct liballoc_minor);
+            l_inuse += size;
+            p = (void *) ((uintptr_t) (maj->first) + sizeof(struct liballoc_minor));
+            ALIGN(p);
+            liballoc_unlock();
+            return p;
+        }
+#endif
+
+#ifdef USE_CASE4
+        min = maj->first;
+
+        while (min != NULL) {
+            if (min->next == NULL) {
+                diff = (uintptr_t) (maj) + maj->size;
+                diff -= (uintptr_t) min;
+                diff -= sizeof(struct liballoc_minor);
+                diff -= min->size;
+                if (diff >= (size + sizeof(struct liballoc_minor))) {
+                    min->next = (struct liballoc_minor *) ((uintptr_t) min + sizeof(struct liballoc_minor) + min->size);
+                    min->next->prev = min;
+                    min = min->next;
+                    min->next = NULL;
+                    min->magic = LIBALLOC_MAGIC;
+                    min->block = maj;
+                    min->size = size;
+                    min->req_size = req_size;
+                    maj->usage += size + sizeof(struct liballoc_minor);
+                    l_inuse += size;
+                    p = (void *) ((uintptr_t) min + sizeof(struct liballoc_minor));
+                    ALIGN(p);
+                    liballoc_unlock();
+                    return p;
+                }
+            }
+
+            if (min->next != NULL) {
+                diff = (uintptr_t) (min->next);
+                diff -= (uintptr_t) min;
+                diff -= sizeof(struct liballoc_minor);
+                diff -= min->size;
+
+                if (diff >= (size + sizeof(struct liballoc_minor))) {
+                    new_min = (struct liballoc_minor *) ((uintptr_t) min + sizeof(struct liballoc_minor) + min->size);
+                    new_min->magic = LIBALLOC_MAGIC;
+                    new_min->next = min->next;
+                    new_min->prev = min;
+                    new_min->size = size;
+                    new_min->req_size = req_size;
+                    new_min->block = maj;
+                    min->next->prev = new_min;
+                    min->next = new_min;
+                    maj->usage += size + sizeof(struct liballoc_minor);
+                    l_inuse += size;
+                    p = (void *) ((uintptr_t) new_min + sizeof(struct liballoc_minor));
+                    ALIGN(p);
+                    liballoc_unlock();
+                    return p;
+                }
+            }
+
+            min = min->next;
+        }
+#endif
+
+#ifdef USE_CASE5
+        if (maj->next == NULL) {
+            if (startedBet == 1) {
+                maj = l_memRoot;
+                startedBet = 0;
+                continue;
+            }
+            maj->next = allocate_new_page(size);
+            if (maj->next == NULL) break;
+            maj->next->prev = maj;
+        }
+#endif
+        maj = maj->next;
+    }
+
+    liballoc_unlock();
+
+    return NULL;
+}
+
+void free(void *ptr)
+{
+    struct liballoc_minor *min;
+    struct liballoc_major *maj;
+
+    if (ptr == NULL) {
+        l_warningCount += 1;
+        return;
+    }
+
+    UNALIGN(ptr);
+    liballoc_lock();
+
+    min = (struct liballoc_minor *) ((uintptr_t) ptr - sizeof(struct liballoc_minor));
+
+    if (min->magic != LIBALLOC_MAGIC) {
+        l_errorCount += 1;
+
+        if (((min->magic & 0xFFFFFF) == (LIBALLOC_MAGIC & 0xFFFFFF)) ||
+            ((min->magic & 0xFFFF) == (LIBALLOC_MAGIC & 0xFFFF)) ||
+            ((min->magic & 0xFF) == (LIBALLOC_MAGIC & 0xFF))) {
+            l_possibleOverruns += 1;
+        }
+
+        liballoc_unlock();
+        return;
+    }
+
+    maj = min->block;
+    l_inuse -= min->size;
+    maj->usage -= (min->size + sizeof(struct liballoc_minor));
+    min->magic = LIBALLOC_DEAD;
+
+    if (min->next != NULL) min->next->prev = min->prev;
+    if (min->prev != NULL) min->prev->next = min->next;
+    if (min->prev == NULL) maj->first = min->next;
+    if (maj->first == NULL) {
+        if (l_memRoot == maj) l_memRoot = maj->next;
+        if (l_bestBet == maj) l_bestBet = NULL;
+        if (maj->prev != NULL) maj->prev->next = maj->next;
+        if (maj->next != NULL) maj->next->prev = maj->prev;
+        l_allocated -= maj->size;
+        liballoc_free(maj, maj->pages);
+    } else {
+        if (l_bestBet != NULL) {
+            int bestSize = l_bestBet->size - l_bestBet->usage;
+            int majSize = maj->size - maj->usage;
+            if (majSize > bestSize) l_bestBet = maj;
+        }
+    }
+    liballoc_unlock();
+}
+
+void *calloc(size_t nobj, size_t size)
+{
+    int real_size;
+    void *p;
+
+    real_size = nobj * size;
+
+    p = malloc(real_size);
+
+    liballoc_memset(p, 0, real_size);
+
+    return p;
+}
+
+void *realloc(void *p, size_t size)
+{
+    void *ptr;
+    struct liballoc_minor *min;
+    unsigned int real_size;
+
+    if (size == 0) {
+        free(p);
+        return NULL;
+    }
+
+    if (p == NULL) return malloc(size);
+
+    ptr = p;
+    UNALIGN(ptr);
+    liballoc_lock();
+    min = (struct liballoc_minor *) ((uintptr_t) ptr - sizeof(struct liballoc_minor));
+
+    if (min->magic != LIBALLOC_MAGIC) {
+        l_errorCount += 1;
+        if (((min->magic & 0xFFFFFF) == (LIBALLOC_MAGIC & 0xFFFFFF)) ||
+            ((min->magic & 0xFFFF) == (LIBALLOC_MAGIC & 0xFFFF)) ||
+            ((min->magic & 0xFF) == (LIBALLOC_MAGIC & 0xFF))) {
+            l_possibleOverruns += 1;
+        }
+
+        liballoc_unlock();
+        return NULL;
+    }
+
+    real_size = min->req_size;
+
+    if (real_size >= size) {
+        min->req_size = size;
+        liballoc_unlock();
+        return p;
+    }
+
+    liballoc_unlock();
+
+    ptr = malloc(size);
+    liballoc_memcpy(ptr, p, real_size);
+    free(p);
+
+    return ptr;
+}
diff --git a/src/userspace/mlibc/stdlib/liballoc.h b/src/userspace/mlibc/stdlib/liballoc.h
new file mode 100644
index 0000000..d21aeb4
--- /dev/null
+++ b/src/userspace/mlibc/stdlib/liballoc.h
@@ -0,0 +1,22 @@
+#ifndef MELVIX_ALLOC_H
+#define MELVIX_ALLOC_H
+
+#include <stddef.h>
+
+int liballoc_lock();
+
+int liballoc_unlock();
+
+void *liballoc_alloc(size_t);
+
+int liballoc_free(void *, size_t);
+
+void *malloc(size_t);
+
+void *realloc(void *, size_t);
+
+void *calloc(size_t, size_t);
+
+void free(void *);
+
+#endif
diff --git a/src/userspace/syscall.c b/src/userspace/syscall.c
new file mode 100644
index 0000000..a6bdc80
--- /dev/null
+++ b/src/userspace/syscall.c
@@ -0,0 +1,18 @@
+#include <syscall.h>
+
+/**
+ * DEFINITIONS
+ */
+DEFN_SYSCALL0(halt, 0);
+
+DEFN_SYSCALL1(write, 1, char *);
+
+DEFN_SYSCALL1(read, 2, char *);
+
+DEFN_SYSCALL1(writec, 3, char *);
+
+DEFN_SYSCALL1(readc, 4, char *);
+
+DEFN_SYSCALL1(paging_alloc, 5, uint32_t);
+
+DEFN_SYSCALL2(paging_free, 6, uint32_t, uint32_t);
\ No newline at end of file
diff --git a/src/userspace/syscall.h b/src/userspace/syscall.h
index 4ddd9d2..5de717e 100644
--- a/src/userspace/syscall.h
+++ b/src/userspace/syscall.h
@@ -1,6 +1,8 @@
 #ifndef MELVIX_SYSCALL_H
 #define MELVIX_SYSCALL_H
 
+#include <stdint.h>
+
 #define DECL_SYSCALL0(fn) int syscall_##fn()
 #define DECL_SYSCALL1(fn, p1) int syscall_##fn(p1)
 #define DECL_SYSCALL2(fn, p1, p2) int syscall_##fn(p1,p2)
@@ -16,7 +18,7 @@
 
 #define DEFN_SYSCALL1(fn, num, P1) \
     int syscall_##fn(P1 p1) { \
-        int __res; __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
+        int __res; __asm__ __volatile__("int $0x80" \
                 : "=a" (__res) \
                 : "0" (num), "b" ((int)(p1)) \
                 : "memory"); \
@@ -25,7 +27,7 @@
 
 #define DEFN_SYSCALL2(fn, num, P1, P2) \
     int syscall_##fn(P1 p1, P2 p2) { \
-        int __res; __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
+        int __res; __asm__ __volatile__("int $0x80" \
                 : "=a" (__res) \
                 : "0" (num), "b" ((int)(p1)), "c"((int)(p2)) \
                 : "memory"); \
@@ -34,7 +36,7 @@
 
 #define DEFN_SYSCALL3(fn, num, P1, P2, P3) \
     int syscall_##fn(P1 p1, P2 p2, P3 p3) { \
-        int __res; __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
+        int __res; __asm__ __volatile__("int $0x80" \
                 : "=a" (__res) \
                 : "0" (num), "b" ((int)(p1)), "c"((p2)), "d"((int)(p3)) \
                 : "memory"); \
@@ -43,7 +45,7 @@
 
 #define DEFN_SYSCALL4(fn, num, P1, P2, P3, P4) \
     int syscall_##fn(P1 p1, P2 p2, P3 p3, P4 p4) { \
-        int __res; __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
+        int __res; __asm__ __volatile__("int $0x80" \
                 : "=a" (__res) \
                 : "0" (num), "b" ((int)(p1)), "c"((int)(p2)), "d"((int)(p3)), "S"((int)(p4)) \
                 : "memory"); \
@@ -52,7 +54,7 @@
 
 #define DEFN_SYSCALL5(fn, num, P1, P2, P3, P4, P5) \
     int syscall_##fn(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) { \
-        int __res; __asm__ __volatile__("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
+        int __res; __asm__ __volatile__("int $0x80" \
                 : "=a" (__res) \
                 : "0" (num), "b" ((int)(p1)), "c"((int)(p2)), "d"((int)(p3)), "S"((int)(p4)), "D"((int)(p5)) \
                 : "memory"); \
@@ -62,24 +64,18 @@
 /**
  * DECLARATIONS
  */
+DECL_SYSCALL0(halt);
+
 DECL_SYSCALL1(write, char *);
 
 DECL_SYSCALL1(read, char *);
 
-DECL_SYSCALL1(writec, char);
-
-DECL_SYSCALL0(readc);
-
-
-/**
- * DEFINITIONS
- */
-DEFN_SYSCALL1(write, 1, char *);
+DECL_SYSCALL1(writec, char *);
 
-DEFN_SYSCALL1(read, 2, char *);
+DECL_SYSCALL1(readc, char *);
 
-DEFN_SYSCALL1(writec, 3, char);
+DECL_SYSCALL1(paging_alloc, uint32_t);
 
-DEFN_SYSCALL0(readc, 4);
+DECL_SYSCALL2(paging_free, uint32_t, uint32_t);
 
 #endif