Jonathan Haws wrote:
Okay, I now have access to the flash memory, however when I write to it the writes do not take. I have tried calling msync() on the mapping to no avail. I have opened the fd with O_SYNC, but cannot get things to work right.Here are the calls: int fd = open("/dev/mem", O_SYNC | O_RDWR); uint16_t * flash = (uint16_t *)mmap(NULL, NOR_FLASH_SIZE, (PROT_READ | PROT_WRITE), MAP_PRIVATE, fd, NOR_FLASH_BASE_ADRS); When I do flash[0] = 0x1234, and then check the value, they do not match. flash[0] = 0x1234; msync(flash, NOR_FLASH_SIZE, MS_SYNC | MS_INVALIDATE); printf("flash[0] = %#04x\n", flash[0]); That prints flash[0] = 0x7f45. I have verified that I am reading the correct values. I can display the flash contents in U-Boot and 7f45 is what is in the first 16 bits of flash. Why can I not write to flash? What am I doing wrong?
Flash does not work that way -- you must send it commands to erase a block, and then further commands to program new data.
It sounds like what you really want is the /dev/mtd or /dev/mtdblock interface, not raw access to the flash chip.
-Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
