Based on the analysis of some troubles such as address mapping and protocol transition when Ad hoc accesses Internet, this paper presents the designing idea and the key technological methods of realizing a gateway which can inter-connected Ad hoc and Internet.

For this issue,the author brings up a series of measures including setting out routing strategies and developing access control rules,and address mapping and intelligent domain name resolution.

In order to enhance the speed that the singlechip runs the file system,which is simplified the format in terms of the FAT16,and the physical address mapping of the memorizer is established,read the efficient data of the SD card directly is adopted,and singlechip runs file system in high efficiency is realized.

When MN requires a new on-Link Care of Address,a temporary address mapping table is built in MAP.

The authors discuss the realization process of remap during the boot process and the management of abnormal vector in boot code.

Besides,it proposes the method and meaning of memory remap.

The paper describe the startup code and diagram of AT91M55800 A chip (ARM7) and detailed the address remap so as to make the reader know the s tartup code for ARM7 mor