Complete Handbook of embedded Linux Application development (s3c2440)

Development Board Hardware:

？ What is the function of each block in the memory of the Development Board?

？ Where should the bare-metal program burn when doing bare metal development? Why? And how is it guided to run?

Bare metal development is in NAND flash?! Other areas such as nor flash line?

Keil, the main () Jump interface address in startup code ***.S determines the address of the Read/write memory area and read/only memory area?

( is the board itself cured have a boot program?) Where are the words stored in memory, how can I see them, and what are the specific functions that are implemented? )

Startup code: ******.S

Part of Bootloader when booting a program

？ What memory can the bare-metal program burn to Ram,nand Flash, Nor flash?

Country embedded light LED routine (actually a boot program, LED light control written to the boot program)

1. Compile and build the executable file

2. Use super terminal to erase NAND flash

3. Download executable files to memory area using USB 0x30000000,gboot.bin Why not download to NAND flash? (This appears to be due to the reason that the LDS linker script specifies that the. bin is generated by. lds. s make and can be gboot.bin disassembled to start the full process and the code holds the address space)

(You can use J-link Commander to load the bin file we want to burn to NAND flash to the memory 0x30000000)

Use J-link V8 and u-boot to write bare-metal programs to s3c2440 NAND flash (assuming nor Flash has burned into the u-boot)

If not burned into the u-boot, you can also first through the J-link commander to the target plate SDRAM initialization Init.bin file loaded into the SRAM (s3c2440 inside the steppingstone, if it is nor start the way, This steppingstone is mapped to the 0x40000000 and is mapped to the 0x0 address if it is started from the NAND. Then set the PC value and run it so that the SDRAM is initialized. Then load the u-boot.bin to an address at the SDRAM, Run U-boot as long as you don't overlap with the other space you need to use.

Function of the program counter PC

Used to store the address of the next instruction. When executing an instruction, it is necessary to take the instruction from memory to the instruction register according to the address of the instruction stored in the PC, which is called "Fetch instruction". At the same time, the address in the PC is either automatically added 1 or the next point is given by the transfer pointer. After that, the instructions are analyzed and executed. Complete the execution of the first instruction, then take out the address of the second instruction according to the PC, so loop, execute each instruction!

• Gpio interface
  • Gpio Related Registers
    • Gpxcon
    • Gpxup
    • Gpxdat
  • Software Access Hardware
    • Accessing a single Pin
    • Bus access to hardware (more common)
      1. 16-bit operation for address alignment
      2. 16-bit operation with misaligned addresses
      3. 8-bit read operations are split by 16-bit
      4. 32-bit read operations are obtained by a 16-bit combination
      5. 16-bit write operation
  • Gpio Operation Instance

Complete Handbook of embedded Linux Application development (s3c2440)