+------------------+ <- 0xFFFFFFFF (4GB)
| 无效空间 |
| |
+------------------+ <- addr: 3G+256M
| 256MB |
| IO外设地址空间 |
| |
+------------------+ <- 0xC0000000 (3GB)
| |
/\/\/\/\/\/\/\/\/\/\
/\/\/\/\/\/\/\/\/\/\
| 无效空间 |
+------------------+ <- 0x40000000 (1GB)
| |
| 实际有效内存 |
| |
+------------------+ <- 0x00100000（1MB）
| BIOS ROM |
+------------------+ <- 0x000F0000 (960KB)
| 16-bit devices, |
| expansion ROMS |
+------------------+ <- 0x000C0000 (768KB)
| VGA Display |
+------------------+ <- 0x000A0000 (640KB)
| |
| Low Memory |
| |
+------------------+ <- 0x00000000
physical address space after memory pages map finished +------------------+ <- 0xFFFFFFFF (4GB)
|32bit设备映射空间 |
+------------------+
| |
+------------------+ <- 实际物理内存空间结束地址
| 空闲内存 |
+------------------+ <- 空闲内存空间的起始地址 freemem
|n*sizeof(struct | <- 管理空闲空间的区域
| Page) |
+------------------+ <- BSS段结束地址
| ucore的BSS段 |
+------------------+ <- 基于ucore数据大小
| ucore的DATA段 |
+------------------+ <- 基于ucore代码大小
| ucore的TEXT段 |
+------------------+ <- 0x00100000（1MB）
| BIOS ROM |
+------------------+ <- 0x000F0000 (960KB)
| 16-bit devices, |
| expansion ROMS |
+------------------+ <- 0x000C0000 (768KB)
| CGA 显存空间 |
+------------------+ <- 0x000B8000
| 空闲内存 |
+------------------+ <- 0x00011000 (+4KB)
|ucore的ELF header |
|数据 |
+------------------+ <- 0x00010000
| 空闲内存 |
+------------------+ <- 基于bootloader大小
|bootloader的TEXT段|
|+ DATA段 |
+------------------+ <- 0x00007C00 (栈顶)
|bootloader和ucore |
|共用的堆栈 |
+------------------+ <- 基于堆栈的使用情况
| Low Memory |
+------------------+ <- 0x00000000
Virtual memory map: Permissions
kernel/user
4G ------------------> +---------------------------------+
| |
| Empty Memory (*) |
| |
+---------------------------------+ 0xFB000000
| Cur. Page Table (Kern, RW) | RW/-- PTSIZE
VPT -----------------> +---------------------------------+ 0xFAC00000
| Invalid Memory (*) | --/--
KERNTOP -------------> +---------------------------------+ 0xF8000000
| |
| Remapped Physical Memory | RW/-- KMEMSIZE
| |
KERNBASE ------------> +---------------------------------+ 0xC0000000
| Invalid Memory (*) | --/--
USERTOP -------------> +---------------------------------+ 0xB0000000
| User stack |
+---------------------------------+
| |
: :
| ~~~~~~~~~~~~~~~~ |
: :
| |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| User Program & Heap |
UTEXT ---------------> +---------------------------------+ 0x00800000
| Invalid Memory (*) | --/--
| - - - - - - - - - - - - - - - |
| User STAB Data (optional) |
USERBASE, USTAB------> +---------------------------------+ 0x00200000
| Invalid Memory (*) | --/--
0 -------------------> +---------------------------------+ 0x00000000