Filesystem in RTEMS

[xuelin.tian at qkmtech.com]

Sorry, I delete some parts of my code. 
The sectors of S25FL256S flash chip has a combination of 4KB and 64KB. Only the 64KB sectors will be used, for simplicity, and the beginning address of them is 0x00020000.

The "beginning" variable I use here is equal to offset plus 0x00020000 (S25FL256S_BOTTOM_GAP_ADDRESS).
The page size of flash is 256B, BTW.

/*******************************************************************************************/
static int flash_write(
    rtems_jffs2_flash_control *super,
    uint32_t offset,
    unsigned char *buffer,
    size_t length) {
    flash_control *self = get_flash_control(super);
    XQspiPs *flash_handle = self->flash_instance;
    uint32_t beginning = offset + S25FL256S_BOTTOM_GAP_ADDRESS;
    uint32_t num = length / S25FL256S_PAGE_SIZE;
    uint32_t remaining = length % S25FL256S_PAGE_SIZE;
    uint32_t written;

    for (written = 0; written < num; written++) {
        FlashWrite(flash_handle, beginning + written*S25FL256S_PAGE_SIZE, \
            S25FL256S_PAGE_SIZE, WRITE_CMD, \
            buffer + written*S25FL256S_PAGE_SIZE);
    }
    if (remaining) {
        FlashWrite(flash_handle, beginning + num*S25FL256S_PAGE_SIZE, \
            remaining, WRITE_CMD, buffer + num*S25FL256S_PAGE_SIZE);
    }
    return S25FL256S_SUCCESS;
}
/*************************************************************************************************/




Best wishes,
xuelin.tian at qkmtech.com
 
From: Sebastian Huber
Date: 2017-10-23 17:44
To: xuelin.tian at qkmtech.com; Chris Johns
CC: users at rtems.org
Subject: Re: Filesystem in RTEMS
On 23/10/17 11:40, Sebastian Huber wrote:
>
>
> On 23/10/17 11:33, xuelin.tian at qkmtech.com wrote:
>> static int flash_write(
>>     rtems_jffs2_flash_control *super,
>>     uint32_t offset,
>>     unsigned char *buffer,
>>     size_t length) {
>>
>>     flash_control *self = get_flash_control(super);
>>     XQspiPs *flash_handle = self->flash_instance;
>>     uint32_t num = length / S25FL256S_PAGE_SIZE;
>>     uint32_t remaining = length % S25FL256S_PAGE_SIZE;
>>     uint32_t written;
>>
>>     for (written = 0; written < num; written++) {
>>         FlashWrite(flash_handle, beginning + written*S25FL256S_PAGE_SIZE, \ 
>>
>>             S25FL256S_PAGE_SIZE, WRITE_CMD, \
>>             buffer + written*S25FL256S_PAGE_SIZE);
>>     }
>>     if (remaining) {
>>         FlashWrite(flash_handle, beginning + num*S25FL256S_PAGE_SIZE, \
>>             remaining, WRITE_CMD, buffer + num*S25FL256S_PAGE_SIZE);
>>     }
>>     return S25FL256S_SUCCESS;
>> }
>>
>> where, my FlashRead and FlashWrite functions will invoke the 
>> functions defined in Xilinx BSP to transfer data from/into flash.
>>
>> I do not know where the problem is...
>
> You assume length % S25FL256S_PAGE_SIZE == 0. 
 
Sorry, I should have read the code more carefully.
 
What is "beginning"? Why don't you use "offset" in this function?
 
-- 
Sebastian Huber, embedded brains GmbH
 
Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
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