minor additions to the kernel heap and adding acpi

kernel/acpi.c

@@ -0,0 +1,53 @@
+#include "acpi.h"
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+
+// Function to find the RSDP (Root System Description Pointer)
+acpi_rsdp_t* acpi_find_rsdp() {
+    // Search memory from 0x000E0000 to 0x00100000 (BIOS)
+    for (uint32_t addr = 0x000E0000; addr < 0x00100000; addr += 16) {
+        acpi_rsdp_t* rsdp = (acpi_rsdp_t*)addr;
+        if (memcmp(rsdp->signature, "RSD PTR ", 8) == 0) {
+            uint8_t checksum = 0;
+            for (int i = 0; i < sizeof(acpi_rsdp_t); i++) {
+                checksum += ((uint8_t*)rsdp)[i];
+            }
+            if (checksum == 0) {
+                return rsdp;  // Valid RSDP found
+            }
+        }
+    }
+    return NULL;  // RSDP not found
+}
+
+// Function to get the RSDT or XSDT based on the RSDP revision
+void* acpi_get_rsdt_or_xsdt(acpi_rsdp_t* rsdp) {
+    if (rsdp->revision >= 2) {
+        return (void*)rsdp->xsdt_addr;  // ACPI 2.0+ uses XSDT
+    } else {
+        return (void*)rsdp->rsdt_addr;  // ACPI 1.0 uses RSDT
+    }
+}
+
+// Function to find the FADT table within the RSDT or XSDT
+acpi_fadt_t* acpi_find_fadt(void* rsdt_or_xsdt) {
+    acpi_rsdt_t* rsdt = (acpi_rsdt_t*)rsdt_or_xsdt;
+    uint32_t num_tables = (rsdt->length - sizeof(acpi_rsdt_t)) / sizeof(uint32_t);
+
+    for (uint32_t i = 0; i < num_tables; i++) {
+        uint32_t table_addr = rsdt->tables[i];
+        acpi_fadt_t* fadt = (acpi_fadt_t*)table_addr;
+        if (fadt->signature == 0x50434146) { // "FACP" in ASCII
+            uint8_t checksum = 0;
+            for (int j = 0; j < fadt->length; j++) {
+                checksum += ((uint8_t*)fadt)[j];
+            }
+            if (checksum == 0) {
+                return fadt;  // Valid FADT found
+            }
+        }
+    }
+    return NULL;  // FADT not found
+}

kernel/acpi.h

@@ -0,0 +1,47 @@
+#ifndef ACPI_H
+#define ACPI_H
+
+#include <stdint.h>
+
+// ACPI base address (replace with actual value)
+#define ACPI_BASE 0xE0000000
+
+#ifndef NULL
+#define NULL ((void*)0)
+#endif
+
+// ACPI RSDP Structure (Root System Description Pointer)
+typedef struct {
+    uint8_t signature[8];      // Should be "RSD PTR "
+    uint8_t checksum;          // Checksum for the RSDP structure
+    uint8_t oem_id[6];         // OEM ID string
+    uint8_t revision;          // ACPI revision
+    uint32_t rsdt_addr;        // 32-bit RSDT address (ACPI 1.0)
+    uint32_t xsdt_addr;        // 64-bit XSDT address (ACPI 2.0+)
+} __attribute__((packed)) acpi_rsdp_t;
+
+// ACPI RSDT Structure (Root System Description Table)
+typedef struct {
+    uint32_t signature;    // Should be "RSDT"
+    uint32_t length;       // Length of the table
+    uint8_t revision;      // Revision of the RSDT table
+    uint8_t checksum;      // Checksum for the RSDT table
+    uint32_t tables[];     // Array of pointers to other tables (RSDT/XSDT entries)
+} __attribute__((packed)) acpi_rsdt_t;
+
+// ACPI FADT Structure (Fixed ACPI Description Table)
+typedef struct {
+    uint32_t signature;         // Should be "FACP"
+    uint32_t length;            // Length of the table
+    uint8_t revision;           // Revision of the FADT table
+    uint8_t checksum;           // Checksum for the FADT table
+    uint32_t pm_tmr_address;    // Power Management Timer Address
+    // ... other FADT fields
+} __attribute__((packed)) acpi_fadt_t;
+
+// Function prototypes
+acpi_rsdp_t* acpi_find_rsdp();
+void* acpi_get_rsdt_or_xsdt(acpi_rsdp_t* rsdp);
+acpi_fadt_t* acpi_find_fadt(void* rsdt_or_xsdt);
+
+#endif /* ACPI_H */

kernel/elf.c

@@ -0,0 +1,50 @@
+#include "elf.h"
+#include <stddef.h>
+#include <string.h>
+
+// This assumes that the elf is ELF32 and little-endian Intel X86 architecture.
+
+// Check if a binary is a valid ELF executable.
+int elf_validate(const void* data) {
+    const Elf32_Ehdr* header = (const Elf32_Ehdr*)data;
+
+    if (*(uint32_t*)header->e_ident != ELF_MAGIC)
+        return 0;
+
+    if (header->e_type != ET_EXEC && header->e_type != ET_DYN)
+        return 0;
+
+    if (header->e_machine != EM_386)
+        return 0;
+
+    return 1;
+}
+
+// Load an ELF executable into memory.
+int elf_load(const void* data, void (*load_segment)(uint32_t vaddr, const void* src, uint32_t size)) {
+    const Elf32_Ehdr* header = (const Elf32_Ehdr*)data;
+    const Elf32_Phdr* ph = (const Elf32_Phdr*)((uint8_t*)data + header->e_phoff);
+
+    for (int i = 0; i < header->e_phnum; i++) {
+        if (ph[i].p_type != PT_LOAD)
+            continue;
+
+        const void* src = (uint8_t*)data + ph[i].p_offset;
+        uint32_t vaddr = ph[i].p_vaddr;
+        uint32_t filesz = ph[i].p_filesz;
+        uint32_t memsz = ph[i].p_memsz;
+
+        // Copy data segment
+        load_segment(vaddr, src, filesz);
+
+        // Zero remaining BSS (if any)
+        if (memsz > filesz) {
+            uint8_t* bss_start = (uint8_t*)(vaddr + filesz);
+            for (uint32_t j = 0; j < memsz - filesz; j++) {
+                bss_start[j] = 0;
+            }
+        }
+    }
+
+    return header->e_entry;
+}

kernel/elf.h

@@ -0,0 +1,52 @@
+#ifndef ELF_H
+#define ELF_H
+
+#include <stdint.h>
+
+#define ELF_MAGIC 0x464C457F  // "\x7FELF" in little-endian
+
+// ELF Types
+#define ET_EXEC 2
+#define ET_DYN  3
+
+// ELF Machine
+#define EM_386  3
+
+// ELF Ident indexes
+#define EI_NIDENT 16
+
+// Program header types
+#define PT_NULL    0
+#define PT_LOAD    1
+
+// ELF Header (32-bit)
+typedef struct {
+    uint8_t  e_ident[EI_NIDENT];
+    uint16_t e_type;
+    uint16_t e_machine;
+    uint32_t e_version;
+    uint32_t e_entry;     // Entry point
+    uint32_t e_phoff;     // Program header table offset
+    uint32_t e_shoff;     // Section header table offset
+    uint32_t e_flags;
+    uint16_t e_ehsize;
+    uint16_t e_phentsize;
+    uint16_t e_phnum;
+    uint16_t e_shentsize;
+    uint16_t e_shnum;
+    uint16_t e_shstrndx;
+} __attribute__((packed)) Elf32_Ehdr;
+
+// Program Header (32-bit)
+typedef struct {
+    uint32_t p_type;
+    uint32_t p_offset;
+    uint32_t p_vaddr;
+    uint32_t p_paddr;
+    uint32_t p_filesz;
+    uint32_t p_memsz;
+    uint32_t p_flags;
+    uint32_t p_align;
+} __attribute__((packed)) Elf32_Phdr;
+
+#endif // ELF_H

kernel/heap.c

@@ -1,6 +1,63 @@
 #include "heap.h"
+#include <stdint.h>
+
+typedef struct heap_block {
+    size_t size;
+    struct heap_block *next;
+    int is_free;
+} heap_block_t;
+
+static heap_block_t *free_list = NULL;
+static void *heap_start_ptr = NULL;
+static void *heap_end_ptr = NULL;
+
+void heap_init(void *heap_start, void *heap_end) {
+    heap_start_ptr = heap_start;
+    heap_end_ptr = heap_end;
+
+    free_list = (heap_block_t *)heap_start;
+    free_list->size = (uintptr_t)heap_end - (uintptr_t)heap_start - sizeof(heap_block_t);
+    free_list->next = NULL;
+    free_list->is_free = 1;
+}
 
 void *heap_alloc(size_t size) {
-    // Heap allocation code
+    heap_block_t *current = free_list;
-    return NULL;
+
+    while (current != NULL) {
+        if (current->is_free && current->size >= size) {
+            // If it's a large block, split it
+            if (current->size > size + sizeof(heap_block_t)) {
+                heap_block_t *new_block = (heap_block_t *)((uintptr_t)current + sizeof(heap_block_t) + size);
+                new_block->size = current->size - size - sizeof(heap_block_t);
+                new_block->next = current->next;
+                new_block->is_free = 1;
+
+                current->next = new_block;
+                current->size = size;
+            }
+
+            current->is_free = 0;
+            return (void *)((uintptr_t)current + sizeof(heap_block_t));
+        }
+
+        current = current->next;
+    }
+
+    return NULL; // Out of memory
+}
+
+void heap_free(void *ptr) {
+    if (ptr == NULL) return;
+
+    heap_block_t *block = (heap_block_t *)((uintptr_t)ptr - sizeof(heap_block_t));
+    block->is_free = 1;
+
+    // Coalesce with next block
+    if (block->next && block->next->is_free) {
+        block->size += block->next->size + sizeof(heap_block_t);
+        block->next = block->next->next;
+    }
+
+    // TODO: Coalesce with previous block for better compaction
 }

kernel/heap.h

@@ -3,6 +3,9 @@
 
 #include <stddef.h>
 
+void heap_init(void *heap_start, void *heap_end);
+
 void *heap_alloc(size_t size);
+void heap_free(void *ptr);
 
 #endif // HEAP_H

kernel/kmain.c

@@ -7,6 +7,7 @@
 #include "paging.h"
 #include "memmap.h"
 #include "gdt.h"
+#include "cpu.h"
 
 #define LPT1 0x378
 
@@ -22,6 +23,10 @@ void kmain(void) {
     serial_init();
     serial_write("Serial port initialized.\n");
 
+    terminal_write("Identifying CPU...\n");
+    identify_cpu();
+    serial_write("CPU identification complete.\n");
+
     lpt_write('L'); // Send 'L' to LPT1 to test
 
     terminal_write("Initializing GDT...\n");
@@ -53,11 +58,17 @@ void kmain(void) {
     serial_write("Memory map retrieved.\n");
 
     terminal_write("Memory Regions:\n");
+
+    char buf[32];
     for (uint32_t i = 0; i < mmap_size; i++) {
-        terminal_write(" - Region: ");
+        terminal_write(" - Base: ");
-        // You would format and print base/length/type here
+        print_hex((uint32_t)(mmap[i].base_addr & 0xFFFFFFFF));  // Lower 32 bits
-        // (e.g., with a basic itoa and print_hex helper)
+        terminal_write(", Length: ");
-        serial_write("Memory region entry\n");
+        print_hex((uint32_t)(mmap[i].length & 0xFFFFFFFF));     // Lower 32 bits
+        terminal_write(", Type: ");
+        itoa(mmap[i].type, buf, 10);
+        terminal_write(buf);
+        terminal_write("\n");
     }
 
     terminal_write("System initialized. Halting.\n");