Fixed position partition splitting and bad blocks on nand flash

csharper2005 · June 19, 2021, 5:38pm

Hi @bmork! Is your problem the same with mine?

github.com/openwrt/openwrt

FS#3887 - MTD partition offset not correctly mapped when bad eraseblocks present

opened 07:05AM - 19 Jun 21 UTC

closed 11:02PM - 26 Feb 23 UTC

openwrt-bot

kernel flyspray

*csharper2005:* - Device problem occurs on: * Beeline Smartbox GIGA with ba…d erase block on NAND flash * Possible other NAND devices with bad erase blocks on flash - Software versions of OpenWrt/LEDE release, packages, etc: <code>OpenWrt SNAPSHOT r16952-677813c776</code> - Steps to reproduce: 1. Write Openwrt kernel (mtd4) and UBI (mtd6) partitions from the stock firmware on a device with badblock(s). 2. Get bootloop: <code>[ 4.040886] mt7530 mdio-bus:1f: Link is Up - 1Gbps/Full - flow control off [ 4.042039] UBI error: no valid UBI magic found inside mtd6 [ 4.065746] hctosys: unable to open rtc device (rtc0) [ 4.076584] /dev/root: Can't open blockdev [ 4.084755] VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6</code> Root cause: 1. Both U-Boot and stock firmware detects a bad eraseblock, all following offsets are sifted by one block (0x20000). Our mtd4 and mtd6 in fact are written at 0x420000 and 0x1020000. <code>******************************************** Flash Map Information ******************************************** Partition Logic_Offs Logic_size Real_Offs Real_Size u-boot 0 100000 0 100000 part_map 100000 100000 100000 100000 factory-data 200000 100000 200000 120000 dual-flag 300000 100000 320000 100000 uImage1 400000 600000 420000 600000 uImage2 a00000 600000 a20000 600000 rootfs1 1000000 1800000 1020000 1800000 rootfs2 2800000 1800000 2820000 1800000 config/log 4000000 800000 4020000 800000 app-tmp 4800000 c00000 4820000 c00000 free-space 5400000 2800000 5420000 2800000 badblock-reserve 7c00000 400000 7c20000 360000</code> 2. U-Boot still waiting for a kernel at 0x420000 and it's ok. 3. Openwrt detects a bad eraseblock, but does NOT shift all following offsets by one block: <code>[ 1.198092] nand: device found, Manufacturer ID: 0xc2, Chip ID: 0xf1 [ 1.210738] nand: Macronix MX30LF1G18AC [ 1.218369] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64 [ 1.233435] mt7621-nand 1e003000.nand: ECC strength adjusted to 4 bits [ 1.246486] mt7621-nand 1e003000.nand: Using programmed access timing: 21005134 [ 1.261038] mt7621-nand 1e003000.nand: Using programmed access timing: 21005134 [ 1.275588] Scanning device for bad blocks [ 1.312129] Bad eraseblock 22 at 0x0000002c0000 [ 2.583817] 8 fixed-partitions partitions found on MTD device mt7621-nand [ 2.597331] Creating 8 MTD partitions on "mt7621-nand": [ 2.607736] 0x000000000000-0x000000100000 : "u-boot" [ 2.618828] 0x000000100000-0x000000200000 : "dynamic partition map" [ 2.632380] 0x000000200000-0x000000300000 : "Factory" [ 2.643531] 0x000000300000-0x000000400000 : "Boot Flag" [ 2.655139] 0x000000400000-0x000000a00000 : "kernel" [ 2.666172] 0x000000a00000-0x000001000000 : "Kernel 2" [ 2.677543] 0x000001000000-0x000007c00000 : "ubi" [ 2.688598] 0x000007c20000-0x000007fa0000 : "bad block reserved"</code> 3. As a result OpenWRT expects to find UBI at 0x1000000. In fact UBI is at 0x10200000. It causes boot loop: <code> [ 4.025957] pci 0000:00:01.0: bridge window [mem 0x60400000-0x604fffff pref] [ 4.040886] mt7530 mdio-bus:1f: Link is Up - 1Gbps/Full - flow control off [ 4.042039] UBI error: no valid UBI magic found inside mtd6 [ 4.065746] hctosys: unable to open rtc device (rtc0) [ 4.076584] /dev/root: Can't open blockdev [ 4.084755] VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6 [ 4.099639] Please append a correct "root=" boot option; here are the available partitions: [ 4.116269] 1f00 1024 mtdblock0 [ 4.116274] (driver?) [ 4.129299] 1f01 1024 mtdblock1 [ 4.129302] (driver?) [ 4.142303] 1f02 1024 mtdblock2 [ 4.142305] (driver?) [ 4.155316] 1f03 1024 mtdblock3 [ 4.155319] (driver?) [ 4.168323] 1f04 6144 mtdblock4 [ 4.168326] (driver?) [ 4.181324] 1f05 6144 mtdblock5 [ 4.181327] (driver?) [ 4.194323] 1f06 110592 mtdblock6 [ 4.194326] (driver?) [ 4.207336] 1f07 3584 mtdblock7 [ 4.207339] (driver?) [ 4.220336] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) [ 4.236804] Rebooting in 1 seconds..</code>

Have you already found a solution?