hi, I am try to port u-boot-1.1.3 on a board with the processor MPC850. And i try to change the board of TQM850.
It boots from flash on the board. I have successfully initialized clock, serial port (connect to RS232). The program can excute in flash and relocate to ram. But I got trouble on board/tqm8xx/flash.c "flash_init()". The problem is finially located get_flash_size(), line 340-342. The 3 lines aim to get flash device ID.
addr[0x0555] = 0x00AA00AA; addr[0x02AA] = 0x00550055; addr[0x0555] = 0x00900090;
I change this code to fit my board: *(volatile unsigned short *) 0x02800aaa = (unsigned short) 0x00aa; *(volatile unsigned short *) 0x02800554 = (unsigned short) 0x0055; *(volatile unsigned short *) 0x02800aaa = (unsigned short) 0x0090; unsigned short ID; ID = *(unsigned short *) 0x02800000; ( address connect as follows: mpc a[11..30] ==>>flash a[19..0], flash a19 ----mpc a11, flasha18 -----mpc a12 ,...... notice LSB of mpc is a[30] not a[31], for flash is word mode. so the flash address "0x555, 0x2aa" are corresponding the system address "0xaaa, 0x554" , left shift by 1 bit.)
those 3 lines code have been tested on vxworks' bootrom on this board.
Now , my trouble is : I cannot use "printf" to print number after executing the 3 line codes, like printf("Device ID is: %x\n",*(unsigned short *) 0x2800000); But it can print string , likes printf("Read Device ID\n"). it seems just the second parameter cause the trouble. Sadly,this kind of "printf" can be used several times , then it stops. other kinds of function or instruction can be executed a little more, but stop finilly.
I simply convert address to string ,then print. The result of ID is 0x0001, which is just the correct number.
If I ignore the 3 line code above, the program runs ok except the initialization of flash. I really cann't figure out where the problem is. Could anyone help me , or give me some suggest!
Below is the configuration on my board: oscillator 4MHz DRAM: 8M flash: AM29LV160DB (16 bit) IMMR.ISB = 0x0220 BR0 = 0x02800801 OR0 = 0xffe00936 Cross Compiler: GNU gcc 4.0.2
Result on hyper-terminal: CPU: XPC850xxZTB at 64 MHz: 2 kB I-Cache 1 kB D-Cache Board: ### No HW ID - assuming TQM8xxL DRAM: 8 MB Now running in RAM - U-Boot at: 007c1000 FLASH: ## Get flash bank 0 size @ 0x02800000 BR0 : 2800801 OR0 : ffe00936
Thanks! Xuguang Li