嵌入式Linux--地址的总结--0x80000000起

痛定思痛。 2022-12-31 06:29 156阅读 0赞

### 目录 ###

*  一、地址空间
 *   *  （1）i.MX6ULL系列芯片
     *   *  i.MX6ULL 应用处理器内存地址映射表
 *  二、正点原子Linux开发板

# 一、地址空间 #

一个颗32位架构的芯片它的寻址空间为

<table> 
 <thead> 
  <tr> 
   <th>大小</th> 
   <th>字节</th> 
   <th>尺寸</th> 
   <th>地址范围</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>2^32（4294967296）</td> 
   <td>4GB</td> 
   <td>0x1 0000 0000</td> 
   <td>0 ~ 0xFFFFFFFF</td> 
  </tr> 
 </tbody> 
</table>

## （1）i.MX6ULL系列芯片 ##

### i.MX6ULL 应用处理器内存地址映射表 ###

来源：《IMX6ULL参考手册》  
**ARM Platform Memory Map**

<table> 
 <thead> 
  <tr> 
   <th align="left">Start address</th> 
   <th align="left">End address</th> 
   <th align="left">Size</th> 
   <th align="left">Description</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td align="left">8000_0000</td> 
   <td align="left">FFFF_FFFF</td> 
   <td align="left">2048 MB</td> 
   <td align="left">MMDC—x16 DDR Controller.</td> 
  </tr> 
  <tr> 
   <td align="left">7000_0000</td> 
   <td align="left">7FFF_FFFF</td> 
   <td align="left">256 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">6000_0000</td> 
   <td align="left">6FFF_FFFF</td> 
   <td align="left">256 MB</td> 
   <td align="left">QSPI1 Memory</td> 
  </tr> 
  <tr> 
   <td align="left">5800_0000</td> 
   <td align="left">5FFF_FFFF</td> 
   <td align="left">128 MB</td> 
   <td align="left">EIM Aliased</td> 
  </tr> 
  <tr> 
   <td align="left">5000_0000</td> 
   <td align="left">57FF_FFFF</td> 
   <td align="left">128 MB</td> 
   <td align="left">EIM (NOR/SRAM)</td> 
  </tr> 
  <tr> 
   <td align="left">1000_0000</td> 
   <td align="left">4FFF_FFFF</td> 
   <td align="left">1024 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0E00_0000</td> 
   <td align="left">0FFF_FFFF</td> 
   <td align="left">32 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0C00_0000</td> 
   <td align="left">0DFF_FFFF</td> 
   <td align="left">32 MB</td> 
   <td align="left">QSPI1 Rx Buffer</td> 
  </tr> 
  <tr> 
   <td align="left">0900_0000</td> 
   <td align="left">0BFF_FFFF</td> 
   <td align="left">48 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0800_0000</td> 
   <td align="left">08FF_FFFF</td> 
   <td align="left">16 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">02C0_0000</td> 
   <td align="left">07FF_FFFF</td> 
   <td align="left">84 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0230_0000</td> 
   <td align="left">02BF_FFFF</td> 
   <td align="left">9 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0220_0000</td> 
   <td align="left">022F_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">Table 2-4 AIPS-3. See IP listing on the separate map.</td> 
  </tr> 
  <tr> 
   <td align="left">0210_0000</td> 
   <td align="left">021F_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">Table 2-3 AIPS-2. See the IP listing on the separate map.</td> 
  </tr> 
  <tr> 
   <td align="left">0200_0000</td> 
   <td align="left">020F_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">Table 2-2 AIPS-1. See the IP listing on the separate map.</td> 
  </tr> 
  <tr> 
   <td align="left">0181_0000</td> 
   <td align="left">01FF_FFFF</td> 
   <td align="left">8128 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0180_C000</td> 
   <td align="left">0180_FFFF</td> 
   <td align="left">16 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0180_8000</td> 
   <td align="left">0180_BFFF</td> 
   <td align="left">16 KB</td> 
   <td align="left">BCH</td> 
  </tr> 
  <tr> 
   <td align="left">0180_6000</td> 
   <td align="left">0180_7FFF</td> 
   <td align="left">8 KB</td> 
   <td align="left">GPMI</td> 
  </tr> 
  <tr> 
   <td align="left">0180_4000</td> 
   <td align="left">0180_5FFF</td> 
   <td align="left">32 KB</td> 
   <td align="left">APBH DMA</td> 
  </tr> 
  <tr> 
   <td align="left">0180_0000</td> 
   <td align="left">0180_3FFF</td> 
   <td align="left">16 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0120_0000</td> 
   <td align="left">017F_FFFF</td> 
   <td align="left">6 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0110_0000</td> 
   <td align="left">011F_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0100_0000</td> 
   <td align="left">010F_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">00F0_0000</td> 
   <td align="left">00FF_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">00E0_0000</td> 
   <td align="left">00EF_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">(per_m) configuration port</td> 
  </tr> 
  <tr> 
   <td align="left">00D0_0000</td> 
   <td align="left">00DF_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">(cpu) configuration port</td> 
  </tr> 
  <tr> 
   <td align="left">00C0_0000</td> 
   <td align="left">00CF_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">GPV_1 PL301</td> 
  </tr> 
  <tr> 
   <td align="left">00B0_0000</td> 
   <td align="left">00BF_FFFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">GPV_0 PL301 configuration port</td> 
  </tr> 
  <tr> 
   <td align="left">00A0_8000</td> 
   <td align="left">00AF_FFFF</td> 
   <td align="left">992 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">00A0_0000</td> 
   <td align="left">00A0_7FFF</td> 
   <td align="left">32 KB</td> 
   <td align="left">ARM Peripherals: GIC400 Only visible to ARM core(s)</td> 
  </tr> 
  <tr> 
   <td align="left">009C_0000</td> 
   <td align="left">009F_FFFF</td> 
   <td align="left">256 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0098_0000</td> 
   <td align="left">009B_FFFF</td> 
   <td align="left">256 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0092_0000</td> 
   <td align="left">0097_FFFF</td> 
   <td align="left">384 KB</td> 
   <td align="left">OCRAM aliased</td> 
  </tr> 
  <tr> 
   <td align="left">0090_0000</td> 
   <td align="left">0091_FFFF</td> 
   <td align="left">128 KB</td> 
   <td align="left">OCRAM 128 KB</td> 
  </tr> 
  <tr> 
   <td align="left">008F_8000</td> 
   <td align="left">008F_FFFF</td> 
   <td align="left">32 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">007F_8000</td> 
   <td align="left">008F_7FFF</td> 
   <td align="left">1 MB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0010_0000</td> 
   <td align="left">0010_7FFF</td> 
   <td align="left">32 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0001_8000</td> 
   <td align="left">000F_FFFF</td> 
   <td align="left">928 KB</td> 
   <td align="left">Reserved</td> 
  </tr> 
  <tr> 
   <td align="left">0001_7000</td> 
   <td align="left">0001_7FFF</td> 
   <td align="left">4 KB</td> 
   <td align="left">Boot ROM—Protected 4 KB area</td> 
  </tr> 
  <tr> 
   <td align="left">0000_0000</td> 
   <td align="left">0001_6FFF</td> 
   <td align="left">92 KB</td> 
   <td align="left">Boot ROM (ROMCP)</td> 
  </tr> 
 </tbody> 
</table>

从上表可以看出，在整个4GB的地址空间内，前2GB的地址空间有其他用处，后2GB的地址空间分配给了内存控制器，所以在操作内存地址的时候都是从0x80000000地址开始的，这其实就限制了该类型（32位架构）的芯片最大支持内存为4GB，而i.MX6ULL芯片所支持的最大的内存为2GB。

# 二、正点原子Linux开发板 #

*  512MB DDR3L
 *  8GB EMMC

对应i.MX6ULL地址映射空间：

我在这里的操作：  
[嵌入式Linux–U-Boot（九）通过TFT/NFS网络更新U-Boot、Kernel、DTB文件][Linux_U-Boot_TFT_NFS_U-Boot_Kernel_DTB]  
可以看到：

=> tftp 80800000 zImage
    Using FEC1 device
    TFTP from server 192.168.0.120; our IP address is 192.168.0.121
    Filename 'zImage'.
    Load address: 0x80800000
    Loading: #################################################################
             #################################################################
             #################################################################
             #################################################################
             #################################################################
             #################################################################
             #################################################################
             ########
             2.4 MiB/s
    done
    Bytes transferred = 6786368 (678d40 hex)
    => tftp 83000000 imx6ull_liefyuan_emmc.dtb
    Using FEC1 device
    TFTP from server 192.168.0.120; our IP address is 192.168.0.121
    Filename 'imx6ull_liefyuan_emmc.dtb'.
    Load address: 0x83000000
    Loading: ###
             2.1 MiB/s
    done
    Bytes transferred = 38823 (97a7 hex)

从上面可以看到：

*  地址0x80800000是从8MB的地方开始的一个内存区域，那前面8MB区域放了些啥玩意？
 *  地址0x83000000是从48MB的地方开始的一个内存区域

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI4ODc3MTI1_size_16_color_FFFFFF_t_70_pic_center]

*  地址一：0x83000000
 *  地址二：0x80800000

[Linux_U-Boot_TFT_NFS_U-Boot_Kernel_DTB]: https://liefyuan.blog.csdn.net/article/details/111148590
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI4ODc3MTI1_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/d0fd7fa38e5d42dd953b714b8b018ba0.png