[U-Boot] Bad block present before NAND flash partition offset
Hi All, In my NAND flash one bad block present before some 'X' binary offset, after this binary partition kernel and rootfs partitions are present. In U-Boot when I access this x binary using the offset address it is not getting binary file content, because of one bad block the 'X' binary flashed in next block after the offset. I used nand_read and nand_read_skip_bad functions, nand_read_skip_bad function is handling if bad block present between offset and the length of the data required after offset.
I want to know is there any function in existing u-boot source code to handle the above issue(if bad blocks present before offset)?
If there is no provision, there are two ways to solve it 1. it is working if I change the offset value of 'X' binary in U-boot source code based on the no. of bad blocks present before offset 'X' binary. 2. Check the no. of bad blocks present before offset at run time and add those many bad blocks length to the offset. First method does not work if different boards NAND flash have bad blocks in different places, but second method handles this.
With the second method, the changes in my specific code to access my 'X' binary, it does not affect common code. After this U-boot is failing to load kernel, because the same issue for kernel also, U-boot is reading the kernel image from the kernel offset, but the kernel image also flashed after 1 block due to 1 bad block. If I follow the above second method here also, I need to do change in "nand read" command function. But with this change it may create some confusion to others in situation like, if some one debugging and wants to read the content from some offset, if bad block present before this offset, it does not read exactly from that offset, it reads after that due to bad block because nand read function is modified above. I want to address this issue in general way, to solve the problem in dynamic way to handle different bad blocks can present in different boards and do not create confusion. Please comment.
I am thinking in nand read function while displaying the content it should print from which address it is displaying, so that if they observe it they know it is displaying after the specified offset due to bad blocks, but people may miss to see the address print.
Thanks.
Hi All, Any suggestions on the above issue? Thanks
On Fri, Jan 18, 2019 at 6:20 PM Madhu koriginja madhava.koriginja@gmail.com wrote:
Hi All, In my NAND flash one bad block present before some 'X' binary offset, after this binary partition kernel and rootfs partitions are present. In U-Boot when I access this x binary using the offset address it is not getting binary file content, because of one bad block the 'X' binary flashed in next block after the offset. I used nand_read and nand_read_skip_bad functions, nand_read_skip_bad function is handling if bad block present between offset and the length of the data required after offset.
I want to know is there any function in existing u-boot source code to handle the above issue(if bad blocks present before offset)?
If there is no provision, there are two ways to solve it
- it is working if I change the offset value of 'X' binary in U-boot
source code based on the no. of bad blocks present before offset 'X' binary. 2. Check the no. of bad blocks present before offset at run time and add those many bad blocks length to the offset. First method does not work if different boards NAND flash have bad blocks in different places, but second method handles this.
With the second method, the changes in my specific code to access my 'X' binary, it does not affect common code. After this U-boot is failing to load kernel, because the same issue for kernel also, U-boot is reading the kernel image from the kernel offset, but the kernel image also flashed after 1 block due to 1 bad block. If I follow the above second method here also, I need to do change in "nand read" command function. But with this change it may create some confusion to others in situation like, if some one debugging and wants to read the content from some offset, if bad block present before this offset, it does not read exactly from that offset, it reads after that due to bad block because nand read function is modified above. I want to address this issue in general way, to solve the problem in dynamic way to handle different bad blocks can present in different boards and do not create confusion. Please comment.
I am thinking in nand read function while displaying the content it should print from which address it is displaying, so that if they observe it they know it is displaying after the specified offset due to bad blocks, but people may miss to see the address print.
Thanks.
participants (1)
-
Madhu koriginja