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Use memory region map to discover the memory

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This commit is contained in:
Kamil Kowalczyk
2025-12-08 01:28:09 +01:00
parent 807f067101
commit 0de8cca8bb
9 changed files with 431 additions and 26 deletions
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5
kernel/platform/i386_pc/boot/_start.S
View File

@@ -29,10 +29,7 @@ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#define F_MEMALIGN (1<<0)
#define F_MEMINFO (1<<1)
#define FLAGS (F_MEMALIGN | F_MEMINFO)
#define FLAGS ((1<<0) | (1<<1))
#define MAGIC (0x1BADB002)
#define CHECKSUM (-(MAGIC + FLAGS))

42
kernel/platform/i386_pc/boot/bootmain.c
View File

@@ -39,6 +39,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <mm/pmm.h>
#include <mm/bba.h>
#include <mm/liballoc.h>
#include <mm/mregmap.h>
#include <config.h>
extern byte_t __kernel_end;
@@ -46,19 +47,47 @@ extern byte_t __kernel_end;
static void dump_multiboot_header(void) {
struct multiboot *mb = multiboot_get();
dbgf("multiboot=%p\n", mb);
dbgf("multiboot=%p, flags=%08x\n", mb, mb->flags);
dbgf("multiboot sanity dump:\n");
dbgf("flags=%08x, mem_low=%08x, mem_up=%08x\n",
mb->flags, mb->mem_low, mb->mem_up);
dbgf("flags=%08x, mem_lower=%08x, mem_upper=%08x\n",
mb->flags, mb->mem_lower, mb->mem_upper);
}
static void mregmap_init1(void) {
struct multiboot *mb = multiboot_get();
struct multiboot_mmap_entry *mmap;
for (mmap = (struct multiboot_mmap_entry *)(mb->mmap_addr + VIRT_BASE);
(uptr_t)mmap < (mb->mmap_addr + VIRT_BASE + mb->mmap_length);
mmap = (struct multiboot_mmap_entry *)((uptr_t)mmap + mmap->size + sizeof(mmap->size))) {
dbgf("mmap entry: size=%08x, addr=%08x, len=%08x, type=%u\n",
mmap->size, mmap->addr1, mmap->len1, mmap->type);
static int type_map[] = {
[1] = MREG_AVAIL_RAM,
[2] = MREG_I386_PC_RESERVED,
[3] = MREG_ACPI,
[4] = MREG_MEM_HBRNT,
[5] = MREG_DEFCT_RMOD,
};
struct mreg mreg = {
.start = (uptr_t)mmap->addr1,
.size = (usize_t)mmap->len1,
.type = type_map[mmap->type],
};
mregmap_add_region(&mreg);
}
}
static void pmm_init1(void) {
struct multiboot *mb = multiboot_get();
dbgf("__kernel_end=%p, %p\n", &__kernel_end, (uptr_t)&__kernel_end - VIRT_BASE);
struct mreg *avail_ram = mregmap_first_avail();
usize_t usable_ram_bytes = mb->mem_up * 1024;
dbgf("usable ram = %zu\n", usable_ram_bytes);
usize_t usable_ram_bytes = avail_ram->size;
dbgf("usable ram = %08x\n", usable_ram_bytes);
uptr_t ram_start = ALIGN_UP((uptr_t)&__kernel_end - VIRT_BASE, 0x1000);
uptr_t ram_end = ALIGN_DOWN(0x100000 + usable_ram_bytes, 0x1000);
@@ -89,6 +118,7 @@ void bootmain(void *mbootptr) {
#endif
dump_multiboot_header();
mregmap_init1();
pmm_init1();
bba_init();
mm_init();

10
kernel/platform/i386_pc/sys/mm.c
View File

@@ -77,10 +77,8 @@ void mm_map_page(struct page_dir *pd, uptr_t vaddr, uptr_t paddr, uint32_t flags
if (!(pd->pd[pd_idx] & PF_PRESENT)) {
pt = (volatile uint32_t *)bba_alloc();
if (pt == 0) {
if (flags & PF_LOCK)
sl_unlock(&pd->sl);
dbgf("mm_map_page(): run out of BBA memory to alloc a PD\n");
return;
goto done;
}
for (usize_t i = 0; i < PAGE_SIZE/sizeof(uint32_t); i++)
@@ -94,6 +92,7 @@ void mm_map_page(struct page_dir *pd, uptr_t vaddr, uptr_t paddr, uint32_t flags
pt[pt_idx] = (paddr & ~(PAGE_SIZE - 1)) | (flags & ~PF_LOCK);
done:
if (flags & PF_LOCK)
sl_unlock(&pd->sl);
}
@@ -107,9 +106,7 @@ void mm_unmap_page(struct page_dir *pd, uptr_t vaddr, uint32_t flags) {
volatile uint32_t *pt;
if (!(pd->pd[pd_idx] & PF_PRESENT)) {
if (flags & PF_LOCK)
sl_unlock(&pd->sl);
return;
goto done;
} else {
uptr_t pt_phys = pd->pd[pd_idx] & ~(PAGE_SIZE - 1);
pt = (volatile uint32_t *)(pt_phys + VIRT_BASE);
@@ -119,6 +116,7 @@ void mm_unmap_page(struct page_dir *pd, uptr_t vaddr, uint32_t flags) {
__asm__ volatile ("invlpg (%0)" :: "r"(vaddr) : "memory");
done:
if (flags & PF_LOCK)
sl_unlock(&pd->sl);
}

1
kernel/platform/i386_pc/sys/mm.h
View File

@@ -49,6 +49,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
it would be inefficient to constantly (un)lock. */
#define KERNEL_HEAP_START 0xF0000000
#define MEM_PROBE_HEAP_START 0xE0000000
struct page_dir {
volatile uint32_t *pd;

254
kernel/platform/i386_pc/sys/multiboot.h
View File

@@ -35,12 +35,256 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <libk/types.h>
#include <libk/compiler.h>
struct multiboot {
uint32_t flags;
uint32_t mem_low;
uint32_t mem_up;
uint32_t boot_dev;
/* 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
{
/* 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 multiboot_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_uint32_t addr1;
multiboot_uint32_t addr2;
multiboot_uint32_t len1;
multiboot_uint32_t len2;
#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;
} 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 */
void multiboot_set(struct multiboot *mb);
struct multiboot *multiboot_get(void);