kheap info

src/mem/gdt.c

@@ -1,107 +0,0 @@
-/*
- * @author  xamidev <xamidev@riseup.net>
- * @brief   Global Descriptor Table (for legacy reasons)
- * @license GPL-3.0-only
- */
-
-#include <mem/gdt.h>
-#include <stdint.h>
-#include <io/serial/serial.h>
-#include <kernel.h>
-
-// Descriptors are 8-byte wide (64bits)
-// So the selectors will be (in bytes): 0x0, 0x8, 0x10, 0x18, etc..
-uint64_t gdt_entries[NUM_GDT_ENTRIES];
-struct GDTR gdtr;
-
-/*
- * gdt_load - Loads Global Descriptor Table
- */
-static void gdt_load()
-{
-    asm("lgdt %0" : : "m"(gdtr));
-}
-
-/*
- * gdt_flush - Flushes the Global Descriptor Table
- *
- * This function loads new Segment Selectors to make
- * the GDT changes take effect
- */
-static void gdt_flush()
-{
-    // Here, 0x8 is the kernel code selector
-    // and 0x10 is the kernel data selector
-    asm volatile (
-        "mov $0x10, %%ax \n" // Reload segments with kernel data selector
-        "mov %%ax, %%ds \n"
-        "mov %%ax, %%es \n"
-        "mov %%ax, %%fs \n"
-        "mov %%ax, %%gs \n"
-        "mov %%ax, %%ss \n"
-
-        "pushq $0x8      \n"   // CS reload
-        "lea 1f(%%rip), %%rax \n"
-        "push %%rax     \n"
-        "lretq          \n"
-        "1:             \n" // Execution continues here after CS reload
-        :
-        :
-        : "rax", "memory"
-    );
-}
-
-/*
- * gdt_init - Global Descriptor Table initialization 
- *
- * This function loads a new GDT in the CPU.
- * It contains a null descriptor, kernel code and data
- * segments, and user code and data segments.
- * However, we do not use segmentation to manage memory on
- * 64-bit x86, as it's deprecated. Instead, we use paging. 
- */
-void gdt_init()
-{
-    // Null descriptor (required)
-    gdt_entries[0] = 0;
-
-    // Kernel code segment
-    uint64_t kernel_code = 0;
-    kernel_code |= 0b1101 << 8; // Selector type: accessed, read-enable, no conforming
-    kernel_code |= 1 << 12; // not a system descriptor
-    kernel_code |= 0 << 13; // DPL field = 0
-    kernel_code |= 1 << 15; // Present
-    kernel_code |= 1 << 21; // Long mode
-
-    // Left shift 32 bits so we place our stuff in the upper 32 bits of the descriptor.
-    // The lower 32 bits contain limit and part of base and therefore are ignored in Long Mode
-    // (because we'll use paging; segmentation is used only for legacy)
-    gdt_entries[1] = kernel_code << 32;
-
-    uint64_t kernel_data = 0;
-    kernel_data |= 0b0011 << 8;
-    kernel_data |= 1 << 12;
-    kernel_data |= 0 << 13;
-    kernel_data |= 1 << 15;
-    kernel_data |= 1 << 21;
-
-    gdt_entries[2] = kernel_data << 32;
-
-    // We re-use the kernel descriptors here, and just update their DPL fields
-    // (Descriptor privilege level) from ring 0 -> to ring 3 (userspace)
-    uint64_t user_code = kernel_code | (3 << 13);
-    gdt_entries[3] = user_code;
-
-    uint64_t user_data = kernel_data | (3 << 13);
-    gdt_entries[4] = user_data;
-
-    // The -1 subtraction is some wizardry explained in the OSDev wiki -> GDT
-    gdtr.limit = NUM_GDT_ENTRIES * sizeof(uint64_t) - 1;
-    gdtr.address = (uint64_t)gdt_entries;
-
-    // Load the GDT we created, flush the old one
-    gdt_load();
-    gdt_flush();
-
-    DEBUG("GDT initialized");
-}

src/mem/kheap.c

@@ -157,4 +157,33 @@ void* kalloc_stack()
 {
     uint8_t* ptr = kmalloc(PROCESS_STACK_SIZE); // As it's out of kmalloc, stack is already mapped into kernel space
     return ptr ? ptr+PROCESS_STACK_SIZE : NULL;
+}
+
+/*
+ * kheap_info - Display heap info
+ *
+ * This function writes the size of the heap (total),
+ * the number of allocated bytes, and the number of
+ * free bytes to the standard output.
+ */
+void kheap_info()
+{
+    uint64_t free_bytes = 0;
+    struct heap_block_t* curr = (struct heap_block_t*)kheap_start;
+
+    while (curr) {
+        if (curr->free == true) {
+            free_bytes += curr->size;
+        }
+        curr = curr->next;
+    }
+
+    uint64_t total = end-kheap_start;
+
+    printf("total=% 8u bytes (%u kB)\r\n"
+                "alloc=% 8u bytes (%u kB)\r\n"
+                " free=% 8u bytes (%u kB)\r\n",
+                total, (total)/1000,
+                total-free_bytes, (total-free_bytes)/1000,
+                free_bytes, free_bytes/1000);
 }