[U-Boot] mtdparts not agreeing wiht fw_printenv

[John Stile]

I am quite confused about partitions in my NAND flash.

Linux can mount my rootfs, so partitions make sense to the kernel, but
from the shell fw_printenv can't read the uboot environment, not matter
what I use in /etc/fw_env.config.

uboot is reading the proper uboot env, and booting the system.

I am using u-boot-2013.01, buildroot-2011.11, 2.6.30 kernel,
at91sam9g20ek.

/proc/cmdline:
mem=64M console=ttyS0,115200 mtdparts=atmel_nand:0x0020000 at 0x00000000(bootstrap1)ro,0x0040000 at 0x00020000(uboot1)ro,0x01A0000 at 0x00060000(env1)ro,0x0200000 at 0x00200000(linux1),0x7C00000 at 0x00400000(rootfs1),0x0020000 at 0x08000000(bootstrap2)ro,0x0040000 at 0x08020000(uboot2)ro,0x01A0000 at 0x08060000(env2)ro,0x0200000 at 0x08200000(linux2),- at 0x08400000(rootfs2);spi0.1-AT45DB642x:0x004200 at 0x0(bootstrap3)ro,0x004200 at 0x4200(env3)ro,0x039C00 at 0x8400(uboot3)ro,0x252000 at 0x42000(linux3),- at 0x294000(rootfs3) root=/dev/mtdblock9 rw rootfstype=jffs2

/proc/mtd 
dev:    size   erasesize  name
mtd0: 00020000 00020000 "bootstrap1"
mtd1: 00040000 00020000 "uboot1"
mtd2: 001a0000 00020000 "env1"
mtd3: 00200000 00020000 "linux1"
mtd4: 07c00000 00020000 "rootfs1"
mtd5: 00020000 00020000 "bootstrap2"
mtd6: 00040000 00020000 "uboot2"
mtd7: 001a0000 00020000 "env2"
mtd8: 00200000 00020000 "linux2"
mtd9: 07c00000 00020000 "rootfs2"
mtd10: 00004200 00000420 "bootstrap3"
mtd11: 00004200 00000420 "env3"
mtd12: 00039c00 00000420 "uboot3"
mtd13: 00252000 00000420 "linux3"
mtd14: 005ac000 00000420 "rootfs3"

dmesg shows:
NAND device: Manufacturer ID: 0x2c, Chip ID: 0xda (Micron NAND 256MiB
3,3V 8-bit)
AT91 NAND: 8-bit, Software ECC
Scanning device for bad blocks
10 cmdlinepart partitions found on MTD device atmel_nand
Creating 10 MTD partitions on "atmel_nand":
0x000000000000-0x000000020000 : "bootstrap1"
0x000000020000-0x000000060000 : "uboot1"
0x000000060000-0x000000200000 : "env1"
0x000000200000-0x000000400000 : "linux1"
0x000000400000-0x000008000000 : "rootfs1"
0x000008000000-0x000008020000 : "bootstrap2"
0x000008020000-0x000008060000 : "uboot2"
0x000008060000-0x000008200000 : "env2"
0x000008200000-0x000008400000 : "linux2"
0x000008400000-0x000010000000 : "rootfs2"
atmel_spi atmel_spi.0: Atmel SPI Controller at 0xfffc8000 (irq 12)
mtd_dataflash spi0.1: AT45DB642x (8448 KBytes) pagesize 1056 bytes (OTP)
5 cmdlinepart partitions found on MTD device spi0.1-AT45DB642x
Creating 5 MTD partitions on "spi0.1-AT45DB642x":
0x000000000000-0x000000004200 : "bootstrap3"
0x000000004200-0x000000008400 : "env3"
0x000000008400-0x000000042000 : "uboot3"
0x000000042000-0x000000294000 : "linux3"
0x000000294000-0x000000840000 : "rootfs3"

I purposefully created more /dev/mtd devices than mtdparts would
require, in order to find which partitions actually contain the uboot
env.

I used 
od -t xz /dev/mtd#
to find the uboot environment partitions,
Then used
dd if=/dev/mtd# of=mtd#_env.bin
to store the contents, so I could compare them.

/dev/mtd4 and /dev/mtd5 create binary equivalent dumps of env1
/dev/mtd14 and /dev/mtd15 create binary equivalent dumps of env2.

/etc/fw_env.config does not like either of those, saying the crc does
not checkout.

/etc/fw_env.config:
/dev/mtd2              0x0          0x20000          0x20000
/dev/mtd2              0x20000      0x20000          0x20000

fw_printenv Output:
Warning: Bad CRC, using default environment
....

Can someone help explain this or what I might be doing wrong?