Learned 5 days arm, today talk about beginner feel

A Of
April 1 start friendly mini2440.   First look at the next board, feel nothing Strange, s3c2440 bus plug SDRAM (for this is not very cold, have been engaged in an FPGA SDRAM controller), NOR. Flash,nand Flash, Enternet PHY +mac chip.  The heart depends on the number of points--------program burned in Flash, power-up after the s2c2440 code from flash into the dram execution ... intuitively think.   . There should be a program to complete the copy, but how the program was first transferred to DRAM (in the back).
. Then hit the CD-ROM friendly manual, roughly doubled, and found that it is all based on operating system programming and a little basic operation, for beginners I cover too much of the underlying details.

. I majored in electrical engineering and automation, combined with their own situation I think should be the first arm as a single-chip computer to make more suitable.

1. Based on the idea above, I should start with the hardware.

(1) First understand s3c2440 inside exactly what thing, is what thing? Needless to say, go straight to datasheet.
A picture in the handbook solves my question.

(Original file name: s3c2440. JPG)

s3c2440 = arm920t + a bunch of things hanging on AHB + a bunch of stuff hanging on an APB
arm920t = Arm920tdmi + a bunch of stuff

s3c2440 inside the peripherals are OK, follow datasheet come on the line.

The bottom point is on the arm920t.
(2) Understanding arm920t
Clear purpose after straight www.arm.com click documention link

(Original file name: ARM header.) JPG)

The information was uploaded a few days ago.
http://www.ouravr.com/bbs/bbs_content.jsp?bbs_sn=3275791&bbs_page_no=1&bbs_id=1032

(Original file name: arm9trm.jpg)

Original arm920t = ARM9TDMI (CPU core) + MMU (memory management unit-------memory protection, address mapping)

Learned in the arm920t_trm1_s.pdf.

(Original file name: what is arm920t. JPG)

I've got the general concept of s3c2440.

s3c2440 = Arm9tdmi + MMU + peripherals connected to AHB (Advanced high performance bus) + devices connected to APB (Advanced peripheral bus)

Two Organize ideas and develop learning plans

1. On the hardware
OK now basically understand the situation, at least know what they are dealing with, thinking clearly after I worked out the study plan:
(1) The use of learning s3c2440, must start from the ARM9TDMI, the specific said ARM9TDMI instruction set, addressing way ... Processor status, interrupts, etc. (practice simulation via ads on the computer).

(2) Learning and ARM9TDMI with the knowledge of the MMU, how to achieve memory protection, virtual address to the Physical address translation ... from these days of research, these are mainly through the coprocessor CP15 control. Of

(the front said arm920t = Arm920tdmi + MMU above the finished arm920t nature will be done)

(3) Learning s3c2440 inside and outside the use of such as LCD controller, watchdog, timer, real clock, USB ... mainly in the s3c2440 datasheet content, can be written for each individual peripheral. Program practice. First learn the use of the serial port, this to the back of the study to help larger, because the program running results from the serial port to the PC verification program is more convenient.

2. On the Software
Now that you've chosen arm with the MMU, you must be running the operating system.
My plan is Linux direction
(1) (Hard direction) Liunx basic Operations (command line)----? General Linux programming------? Linux driver Authoring----? software porting-----? kernel porting
(2) (soft direction) Linux basic Operations (command line)---? General Linux Programming-------? Network programming, QT graphical interface programming ...
(need to have basic knowledge--------compilation, c,c++, Os ... ）

3. Tool chain use

(1) Programming tools
Under Windows platform:
The Windows platform is good to have these kinds of ide:ads,keil,iar
Early learning chooses the most inconvenient-------ADS (and of course more inconvenient, like compiling, compiling, linking directly on the command line)


Under Linux platforms:
GCC, assembler, linker use

(2) Debugging Tools
mini2440 H-JATG, Jlink and other debugger agent usage and how to configure in the IDE



These are my learning ideas and plans.

Three Finding the first sense of accomplishment
Said above, I am ready to s3c2440 as a single-chip computer, the bottom is my first arm program-------LED running lights


Operating platform: Friendly mini2440
Operating system support is required: no

Based on the MINI2440 Development Board CD-ROM program slightly modified

Click here to download Ourdev_433343.rar (file size: 63K) (Original file name: Led.rar)
The program is very simple, the most difficult is the start code that block (direct use of the CD-ROM startup code, recently in the study to start the block), in fact, the startup code itself is not difficult, is to complete the following several functions
1. Initializes the stack,
2. Set interrupts,
3. Initializing peripherals, clocks
4. Switch Processor mode
5. Jump to User program portal

The program can be downloaded directly from the Supervivi to memory run, because the program is less than 4K so it can also be directly burned in NAND flash run
(because s3c2440 supports booting from NAND, with 4KSRAM on-chip for running bootloader, which is a small piece of bootloader that was used to copy)

ARM's instruction set is not ripe, independent write a boot code is not enough, a few days thoroughly understand, a separate post to talk about the startup code.

Learned 5 days arm, today talk about beginner feel (turn)