feature: memory limit with multiboot (wip, still crashing)

headers/memory.h

@@ -23,6 +23,7 @@ extern uint32_t _kernel_end;
 extern uint32_t boot_page_directory;
 extern uint32_t *page_directory;
 extern uint32_t page_table_default[1024];
+extern uint32_t mem_size;
 
 uint32_t *virt_to_phys(uint32_t *virt_addr);
 void init_memory(void);

headers/multiboot.h

@@ -0,0 +1,262 @@
+/* multiboot.h - Multiboot header file. */
+/* Copyright (C) 1999,2003,2007,2008,2009,2010  Free Software Foundation, Inc.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL ANY
+ *  DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#pragma once
+
+/* How many bytes from the start of the file we search for the header. */
+#define MULTIBOOT_SEARCH       8192
+#define MULTIBOOT_HEADER_ALIGN 4
+
+/* The magic field should contain this. */
+#define MULTIBOOT_HEADER_MAGIC 0x1BADB002
+
+/* This should be in %eax. */
+#define MULTIBOOT_BOOTLOADER_MAGIC 0x2BADB002
+
+/* Alignment of multiboot modules. */
+#define MULTIBOOT_MOD_ALIGN 0x00001000
+
+/* Alignment of the multiboot info structure. */
+#define MULTIBOOT_INFO_ALIGN 0x00000004
+
+/* Flags set in the ’flags’ member of the multiboot header. */
+
+/* Align all boot modules on i386 page (4KB) boundaries. */
+#define MULTIBOOT_PAGE_ALIGN 0x00000001
+
+/* Must pass memory information to OS. */
+#define MULTIBOOT_MEMORY_INFO 0x00000002
+
+/* Must pass video information to OS. */
+#define MULTIBOOT_VIDEO_MODE 0x00000004
+
+/* This flag indicates the use of the address fields in the header. */
+#define MULTIBOOT_AOUT_KLUDGE 0x00010000
+
+/* Flags to be set in the ’flags’ member of the multiboot info structure. */
+
+/* is there basic lower/upper memory information? */
+#define MULTIBOOT_INFO_MEMORY 0x00000001
+/* is there a boot device set? */
+#define MULTIBOOT_INFO_BOOTDEV 0x00000002
+/* is the command-line defined? */
+#define MULTIBOOT_INFO_CMDLINE 0x00000004
+/* are there modules to do something with? */
+#define MULTIBOOT_INFO_MODS 0x00000008
+
+/* These next two are mutually exclusive */
+
+/* is there a symbol table loaded? */
+#define MULTIBOOT_INFO_AOUT_SYMS 0x00000010
+/* is there an ELF section header table? */
+#define MULTIBOOT_INFO_ELF_SHDR 0X00000020
+
+/* is there a full memory map? */
+#define MULTIBOOT_INFO_MEM_MAP 0x00000040
+
+/* Is there drive info? */
+#define MULTIBOOT_INFO_DRIVE_INFO 0x00000080
+
+/* Is there a config table? */
+#define MULTIBOOT_INFO_CONFIG_TABLE 0x00000100
+
+/* Is there a boot loader name? */
+#define MULTIBOOT_INFO_BOOT_LOADER_NAME 0x00000200
+
+/* Is there a APM table? */
+#define MULTIBOOT_INFO_APM_TABLE 0x00000400
+
+/* Is there video information? */
+#define MULTIBOOT_INFO_VBE_INFO         0x00000800
+#define MULTIBOOT_INFO_FRAMEBUFFER_INFO 0x00001000
+
+#ifndef ASM_FILE
+
+typedef unsigned char multiboot_uint8_t;
+typedef unsigned short multiboot_uint16_t;
+typedef unsigned int multiboot_uint32_t;
+typedef unsigned long long multiboot_uint64_t;
+
+struct multiboot_header {
+	/* Must be MULTIBOOT_MAGIC - see above. */
+	multiboot_uint32_t magic;
+
+	/* Feature flags. */
+	multiboot_uint32_t flags;
+
+	/* The above fields plus this one must equal 0 mod 2^32. */
+	multiboot_uint32_t checksum;
+
+	/* These are only valid if MULTIBOOT_AOUT_KLUDGE is set. */
+	multiboot_uint32_t header_addr;
+	multiboot_uint32_t load_addr;
+	multiboot_uint32_t load_end_addr;
+	multiboot_uint32_t bss_end_addr;
+	multiboot_uint32_t entry_addr;
+
+	/* These are only valid if MULTIBOOT_VIDEO_MODE is set. */
+	multiboot_uint32_t mode_type;
+	multiboot_uint32_t width;
+	multiboot_uint32_t height;
+	multiboot_uint32_t depth;
+};
+
+/* The symbol table for a.out. */
+struct multiboot_aout_symbol_table {
+	multiboot_uint32_t tabsize;
+	multiboot_uint32_t strsize;
+	multiboot_uint32_t addr;
+	multiboot_uint32_t reserved;
+};
+typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;
+
+/* The section header table for ELF. */
+struct multiboot_elf_section_header_table {
+	multiboot_uint32_t num;
+	multiboot_uint32_t size;
+	multiboot_uint32_t addr;
+	multiboot_uint32_t shndx;
+};
+typedef struct multiboot_elf_section_header_table
+    multiboot_elf_section_header_table_t;
+
+struct multiboot_info {
+	/* Multiboot info version number */
+	multiboot_uint32_t flags;
+
+	/* Available memory from BIOS */
+	multiboot_uint32_t mem_lower;
+	multiboot_uint32_t mem_upper;
+
+	/* "root" partition */
+	multiboot_uint32_t boot_device;
+
+	/* Kernel command line */
+	multiboot_uint32_t cmdline;
+
+	/* Boot-Module list */
+	multiboot_uint32_t mods_count;
+	multiboot_uint32_t mods_addr;
+
+	union {
+		multiboot_aout_symbol_table_t aout_sym;
+		multiboot_elf_section_header_table_t elf_sec;
+	} u;
+
+	/* Memory Mapping buffer */
+	multiboot_uint32_t mmap_length;
+	multiboot_uint32_t mmap_addr;
+
+	/* Drive Info buffer */
+	multiboot_uint32_t drives_length;
+	multiboot_uint32_t drives_addr;
+
+	/* ROM configuration table */
+	multiboot_uint32_t config_table;
+
+	/* Boot Loader Name */
+	multiboot_uint32_t boot_loader_name;
+
+	/* APM table */
+	multiboot_uint32_t apm_table;
+
+	/* Video */
+	multiboot_uint32_t vbe_control_info;
+	multiboot_uint32_t vbe_mode_info;
+	multiboot_uint16_t vbe_mode;
+	multiboot_uint16_t vbe_interface_seg;
+	multiboot_uint16_t vbe_interface_off;
+	multiboot_uint16_t vbe_interface_len;
+
+	multiboot_uint64_t framebuffer_addr;
+	multiboot_uint32_t framebuffer_pitch;
+	multiboot_uint32_t framebuffer_width;
+	multiboot_uint32_t framebuffer_height;
+	multiboot_uint8_t framebuffer_bpp;
+#define MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED  0
+#define MULTIBOOT_FRAMEBUFFER_TYPE_RGB      1
+#define MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT 2
+	multiboot_uint8_t framebuffer_type;
+	union {
+		struct {
+			multiboot_uint32_t framebuffer_palette_addr;
+			multiboot_uint16_t framebuffer_palette_num_colors;
+		};
+		struct {
+			multiboot_uint8_t framebuffer_red_field_position;
+			multiboot_uint8_t framebuffer_red_mask_size;
+			multiboot_uint8_t framebuffer_green_field_position;
+			multiboot_uint8_t framebuffer_green_mask_size;
+			multiboot_uint8_t framebuffer_blue_field_position;
+			multiboot_uint8_t framebuffer_blue_mask_size;
+		};
+	};
+};
+typedef struct multiboot_info multiboot_info_t;
+
+struct multiboot_color {
+	multiboot_uint8_t red;
+	multiboot_uint8_t green;
+	multiboot_uint8_t blue;
+};
+
+struct multiboot_mmap_entry {
+	multiboot_uint32_t size;
+	multiboot_uint64_t addr;
+	multiboot_uint64_t len;
+#define MULTIBOOT_MEMORY_AVAILABLE        1
+#define MULTIBOOT_MEMORY_RESERVED         2
+#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE 3
+#define MULTIBOOT_MEMORY_NVS              4
+#define MULTIBOOT_MEMORY_BADRAM           5
+	multiboot_uint32_t type;
+} __attribute__((packed));
+typedef struct multiboot_mmap_entry multiboot_memory_map_t;
+
+struct multiboot_mod_list {
+	/* the memory used goes from bytes ’mod_start’ to ’mod_end-1’ inclusive
+	 */
+	multiboot_uint32_t mod_start;
+	multiboot_uint32_t mod_end;
+
+	/* Module command line */
+	multiboot_uint32_t cmdline;
+
+	/* padding to take it to 16 bytes (must be zero) */
+	multiboot_uint32_t pad;
+};
+typedef struct multiboot_mod_list multiboot_module_t;
+
+/* APM BIOS info. */
+struct multiboot_apm_info {
+	multiboot_uint16_t version;
+	multiboot_uint16_t cseg;
+	multiboot_uint32_t offset;
+	multiboot_uint16_t cseg_16;
+	multiboot_uint16_t dseg;
+	multiboot_uint16_t flags;
+	multiboot_uint16_t cseg_len;
+	multiboot_uint16_t cseg_16_len;
+	multiboot_uint16_t dseg_len;
+};
+
+#endif /* ! ASM_FILE */

src/boot.s

@@ -113,6 +113,9 @@ _start:
 	# Set up the stack.
 	mov $stack_top, %esp
 
+	push %eax
+	push %ebx
+
 	# Enter the high-level kernel.
 	call kernel_main
 

src/kernel.c

@@ -5,6 +5,7 @@
 #include "idt.h"
 #include "kprintf.h"
 #include "memory.h"
+#include "multiboot.h"
 #include "power.h"
 #include "shell.h"
 #include "string.h"
@@ -25,40 +26,48 @@
 #error "This tutorial needs to be compiled with a ix86-elf compiler"
 #endif
 
-void kernel_main(void)
+/* Par contre je me dois d'être honnête avec toi, j'ai passé un très bon moment
+ * hier soir c'était vraiment posé et tout mais j'ai pas trop ressenti de
+ * feeling qui me donnerait envie de continuer dans une relation "couple" sur le
+ * long terme. Je sais pas trop comment le dire sans que ça te blesse, c'est pas
+ * personnel ou quoi c'est cool quand on parle et tout mais juste je ne pense
+ * pas pouvoir faire marcher une relation comme celle là :( */ /* Voilà je voulais juste te le dire pour pas que tu te mettes quelque chose en
+ * tête qui n'arrivera pas, je trouve ça plus correct */
+
+static void set_mem_size(multiboot_info_t *mbd, uint32_t magic)
+{
+	/* Make sure the magic number matches for memory mapping */
+	if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
+		kpanic("invalid magic number!");
+
+	/* Check bit 6 to see if we have a valid memory map */
+	if (!(mbd->flags >> 6 & 0x1))
+		kpanic("invalid memory map given by GRUB bootloader");
+
+	/* Loop through the memory map and display the values */
+	for (uint32_t i = 0; i < mbd->mmap_length;
+	     i += sizeof(multiboot_memory_map_t)) {
+		multiboot_memory_map_t *mmmt =
+		    (multiboot_memory_map_t *)(mbd->mmap_addr + i);
+		if (mmmt->type == MULTIBOOT_MEMORY_AVAILABLE)
+			mem_size += mmmt->len;
+	}
+}
+
+void kernel_main(multiboot_info_t *mbd, uint32_t magic)
 {
 	terminal_initialize();
 	init_gdt();
 	init_idt();
 	init_memory();
 	load_drivers();
+	set_mem_size(mbd, magic);
 	kprintf(KERN_ALERT
 	        "I see no way to confuse an array of 256 seg:off pairs with a "
 	        "complex 8*unknown quantity -byte descriptor table. -- Troy "
 	        "Martin 03:50, 22 March 2009 (UTC)\n");
-	for (uint16_t i = 0;; i++) {
+	/* vmalloc(10); */
-		void *ptr = alloc_pages(4096);
-		PRINT_PTR(ptr);
-		memset(ptr, ~0, 4096);
-		free_pages(ptr, 4096);
-	}
-	/* int i = 0; */
 	/* while (vmalloc(10)) */
 	/* 	; */
-	/* if (i++ > 70000) */
-	/* 	kprintf("%d\n", i); */
-	/* void *tab[1024]; */
-	/* for (int i = 0; i < 1023; i++) { */
-	/* 	tab[i] = alloc_pages(1, NULL); */
-	/* 	PRINT_INT(i); */
-	/* 	PRINT_PTR(tab[i]); */
-	/* 	if (!tab[i]) */
-	/* 		break; */
-	/* 	memset(tab[i], i, 4096); */
-	/* } */
-	/* PRINT_UINT(((uint8_t *)tab[0])[0]); */
-	/* for (int i = 0; i < 10; i++) */
-	/* 	PRINT_UINT(((uint8_t *)tab[i])[0]); */
-	/* PRINT_PTR(tab[i]); */
 	shell_init();
 }

src/memory/frame.c

@@ -8,6 +8,7 @@
 #include "utils.h"
 
 #define MAX_FRAMES (HEAP_END / PAGE_SIZE)
+#define NB_FRAMES  (mem_size / PAGE_SIZE)
 
 enum {
 	FREE,
@@ -19,7 +20,7 @@ static uint8_t frame_table[MAX_FRAMES];
 static int32_t find_next_block(size_t nb_frames)
 {
 	for (uint32_t i = CEIL(HEAP_START, PAGE_SIZE);
-	     i + nb_frames < MAX_FRAMES; i++) {
+	     i + nb_frames < NB_FRAMES; i++) {
 		uint32_t j;
 		for (j = 0; frame_table[i + j] == FREE && j < nb_frames; j++)
 			;
@@ -39,7 +40,7 @@ void *alloc_frames(size_t size)
 		return NULL;
 	}
 	for (size_t j = 0; j < nb_frames; j++) {
-		assert(j + i < MAX_FRAMES);
+		assert(j + i < NB_FRAMES);
 		frame_table[j + i] = USED;
 	}
 	return (void *)(i * PAGE_SIZE);
@@ -50,13 +51,13 @@ int free_frames(void *frame_ptr, size_t size)
 	const uint32_t nb_frames = CEIL(size, PAGE_SIZE);
 	const uint32_t start = (uint32_t)frame_ptr / PAGE_SIZE;
 
-	if (start > MAX_FRAMES) {
+	if (start > NB_FRAMES) {
 		kprintf(KERN_WARNING "Address out of range\n");
 		return -1;
 	} else if ((uint32_t)frame_ptr % PAGE_SIZE) {
 		kprintf(KERN_WARNING "Invalid address\n");
 		return -1;
-	} else if (start + nb_frames > MAX_FRAMES) {
+	} else if (start + nb_frames > NB_FRAMES) {
 		kprintf(KERN_WARNING "Invalid number of frames\n");
 		return -1;
 	}

src/memory/memory.c

@@ -6,6 +6,7 @@
 
 uint32_t *page_directory = &boot_page_directory;
 uint32_t page_table_default[1024] __attribute__((aligned(4096)));
+uint32_t mem_size;
 
 void init_memory(void)
 {

src/shell/commands/merdella_cmd.c

@@ -46,5 +46,4 @@ void merdella_cmd(char *arg)
 {
 	(void)arg;
 	kprintf(POOP);
-	int i = 1 / 0;
 }