ARM7 LPC2378 remote upgrade ---- IAP function

    For In Application Programming (IAP), the IAP procedure should be called by pointing the word pointer in register r0 to the memory (RAM) containing the command code and parameters. The result of the IAP command is returned to the result table pointed to by register r1. The user can reuse the command table to obtain the result by passing the same pointer in registers r0 and r1. The parameter table should be large enough to store all the results in case the number of results is greater than the number of parameters. The parameter passing process is shown in the figure below.

    The number of parameters and results varies according to the IAP command. The maximum number of parameters is 5, which are passed to the "Copy RAM to Flash" command. The maximum number of results is 2, which are returned by the "Sector Check Empty" command. The command handler sends the status code INVALID_COMMAND when it receives an undefined command. The IAP routine is thumb code and is located at address 0x7FFF FFF0.

    The IAP function can be called using the following C code. Define the entry address of the IAP program. Since the 0th bit of the IAP address is 1, when the program counter is transferred to this address, it will cause a change in the Thumb instruction set. The IAP function code is attached below:

1. /****************************************************** *  

2. Name: Macro definition (Flash operation)  

3. *************************************************** /  

4. #define IAP_LOCATION 0x7FFFFFF1 //Define the entry address of the IAP program  

5. #define IapGetAddr(addr) (volatile uint16 *)(0x80000000|(addr