[U-Boot] about ## Unknown FLASH on Bank 0

[Peter Pan]

I have checked this problem again, and find out the reason why sometimes
we get a false value of the ID0 we read from norflash.

When we read IDs from norflash, we first write the read id command:

AMD_SEND_CMD(baseaddr, ACMD_READMODE);
AMD_SEND_CMD((baseaddr | LATCH_OFFSET1), ACMD_UNLOCK1);
AMD_SEND_CMD((baseaddr | LATCH_OFFSET2), ACMD_UNLOCK2);
AMD_SEND_CMD((baseaddr | LATCH_OFFSET1), ACMD_ID);

then we read the IDs from norflash:
pAddr = (unsigned short *)(baseaddr & 0xFFFFFF00); //Manufacture Id
code0 = *(pAddr);   //cycle 4: Addr: X00    data = 0x01
pAddr = (unsigned short *)(baseaddr + DEVICE_CODE1_OFFSET_2X16);
code1 = *pAddr;     //cycle 4: Addr: X01, X - don't care. data = 0x227E
pAddr = (unsigned short *)(baseaddr + DEVICE_CODE2_OFFSET_2X16);
code2 = *pAddr;     //cycle 5: Addr: X0E    data = 0x2223
pAddr = (unsigned short *)(baseaddr + DEVICE_CODE3_OFFSET_2X16);
code3 = *(pAddr);   //cycle 6: Addr: X0F    data = 0x2201
AMD_SEND_CMD(baseaddr, ACMD_READMODE);

We need to add a `__asm__ __volatile__ ("sync"); ` between the write
and read operation to always get a correct result.


2009/10/28 Peter Pan <pppeterpppan at gmail.com>

> Dear Wolfgang Denk:
>
> Our hardware should be fine. We run VxWorks on it before and it works fine.
> The hardware running VxWorks is already
> a mature product of our company. We recently want to run linux on it
> because of the high price of VxWorks.
>
> I do a little experiments on the U-Boot-2009-08, any I successfully make
> the "Unknown Flash on Bank 0" appear without any
> code modification on common files. I only add my board specification files
> and my config file, change the Makefile to
> support my board files to compile, then the "unknown flash on bank 0"
> appears.
>
> I use ELDK for cross compile, and the ELDK gcc version is :
> ppc_6xx-gcc(GCC) 4.2.2
>
> Which part of the code may cause this kind of problem? Maybe I can send
> your that part of my codes.
>
> 2009/10/27 Wolfgang Denk <wd at denx.de>
>
>> Dear Peter Pan,
>>
>>
>> please keel the mailinmg list on Cc:
>>
>> In message <48abf2c20910261812g75d17990jd1793f0560bc882c at mail.gmail.com>
>> you wrote:
>> >
>> > I also think the 1.2.0 is an ancient version, so I migrate my u-boot
>> from
>> > 1.2.0 to u-boot-2009-08 yestoday, the same "Unknown Flash Bank" problem
>> > happened.
>> > I changed a little in the common files, all of which I think should not
>> lead
>> > to this "Unknown Flash Bank" problem.
>> > I use MPC8247, and all my changes are:
>>
>> Which exact board are you using?
>>
>> > 1. in /common/env_common.c, I add my environment variables to array
>> > default_environment.
>>
>> Bad, very bad. You should never meddle with this file. You should add
>> your custom settings to your board config file only.
>>
>> > 2. in /cpu/mpc8260/cpu_init.c, in function cpu_init_f, I common this
>> line
>> > "immr->im_clkrst.car_rsr = RSR_ALLBITS;", because I will need RSR
>> register
>> > value later
>> > 3. in /cpu/mpc8260/serial_smc.c, we use BRG1 for SMC1 instead of BRG7
>>
>> You are not supposed to meddle with these files. No changes to such
>> common files are necessary to port U-Boot to custom hardware.
>>
>> > 4. in /include/mpc8260.h, we add a hardware dog kick function, and
>> modified
>> > functiion "reset_8260_watchdog" a little to kick the hardware dog.
>> > 5. in /common/main.c, we add support to the two jumper on our board,
>> which
>> > is just two "if... else...".
>>
>> Such changes should be done in board specific code, not in common
>> files.
>>
>> > 6. in our board specific files, they all works fine before and I did not
>> > change a thing.
>> > Make all the changes above, the u-boot works fine. then I modified the
>> > /common/cmd_mem.c, we make the mtest command to test memory only once(in
>> > CFG_ALT_MEMTEST mode).
>> > I change the "for(;;)" to for(;iterations == 1;)", then the "Unknown
>> Flash
>> > Bank" happens.
>> > I printed out the 4 Flash IDs, the Manufacture Id changes from
>> 0x01(normal)
>> > to 0x808(wrong!!), other IDs are all normal.
>>
>> This makes zero sense to me.
>>
>> I understand you have a custom board with local modifications. That
>> means we don't know neither your hardware nor your code, which makes
>> it impossible to help. From the symptoms you describe, there must be
>> something fundamentally broken with your port, but without seeing your
>> code we cannot even guess what this might be.
>>
>> Best regards,
>>
>> Wolfgang Denk
>>
>> --
>> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
>> The high cost of living hasn't affected its popularity.
>>
>
>