blob: 3d69ed5839ccc7a02d353273c7e38f853d659257 [file] [log] [blame]
Stefano Babiceae49882011-01-20 08:05:15 +00001Overview
2--------------
3
4mx35pdk (known als as mx35_3stack) is a development board by Freescale.
5It consists of three pluggable board:
6 - CPU module, with CPU, RAM, flash
7 - Personality board, with most interfaces (USB, Network,..)
8 - Debug board with JTAG header.
9
10The board is usually delivered with redboot. This howto explains how to boot
11a linux kernel and how to replace the original bootloader with U-Boot.
12
13The board is delivered with Redboot on the NAND flash. It is possible to
14switch the boot device with the switches SW1-SW2 on the Personality board,
15and with SW5-SW10 on the Debug board.
16
17Delivered Redboot script to start the kernel
18---------------------------------------------------
19
20In redboot the following script is stored:
21
22fis load kernel
23exec -c "noinitrd console=ttymxc0,115200 root=/dev/mtdblock8 rw rootfstype=jffs2 ip=dhcp fec_mac=00:04:9F:00:E7:76"
24
25Kernel is taken from flash. The image is in zImage format.
26
27Booting from NET, rootfs on NFS:
28-----------------------------------
29
30To change the script in redboot:
31
32load -r -b 0x100000 <path_to_zImage>
33exec -c "noinitrd console=ttymxc0,115200 root=/dev/nfsroot rootfstype=nfsroot nfsroot=192.168.1.1:/opt/eldk-4.2-arm/armVFP rw ip=dhcp"
34
35If the ip address is not set, you can set it with :
36
37ip_address -l <board_ip/netmask> -h <server_ip>
38
39Linux partitions:
40---------------------------
41
42As default, the board is shipped with these partition tables for NAND
43and for NOR:
44
45Creating 5 MTD partitions on "NAND 2GiB 3,3V 8-bit":
460x00000000-0x00100000 : "nand.bootloader"
470x00100000-0x00600000 : "nand.kernel"
480x00600000-0x06600000 : "nand.rootfs"
490x06600000-0x06e00000 : "nand.configure"
500x06e00000-0x80000000 : "nand.userfs"
51
52Creating 6 MTD partitions on "mxc_nor_flash.0":
530x00000000-0x00080000 : "Bootloader"
540x00080000-0x00480000 : "nor.Kernel"
550x00480000-0x02280000 : "nor.userfs"
560x02280000-0x03e80000 : "nor.rootfs"
570x01fe0000-0x01fe3000 : "FIS directory"
580x01fff000-0x04000000 : "Redboot config"
59
60NAND partitions can be recognized enabling in kernel CONFIG_MTD_REDBOOT_PARTS.
61For this board, CONFIG_MTD_REDBOOT_DIRECTORY_BLOCK should be set to 2.
62
63However, the setup in redboot is not correct and does not use the whole flash.
64
65Better solution is to use the kernel parameter mtdparts.
66Here the resulting script to be defined in RedBoot with fconfig:
67
68load -r -b 0x100000 sbabic/mx35pdk/zImage.2.6.37
69exec -c "noinitrd console=ttymxc0,115200 root=/dev/nfsroot rootfstype=nfsroot nfsroot=192.168.1.1:/opt/eldk-4.2-arm/arm rw ip=dhcp mtdparts=mxc_nand:1m(boot),5m(linux),96m(root),8m(cfg),1938m(user);physmap-flash.0:512k(b),4m(k),30m(u),28m(r)"
70
71Flashing U-Boot
72--------------------------------
73
74There are two options: the original bootloader in NAND can be replaced with
75u-boot, or u-boot can be stored on the NOR flash without erasing
76the delivered bootloader.
77The boot storage can be select using the switches on the personality board
78(SW1-SW2) and on the DEBUG board (SW4-SW10).
79
80The second option is to be preferred if you have not a JTAG debugger.
81If something goes wrong flashing the bootloader, it is always possible to
82recover the board booting from the other device.
83
84Replacing the bootloader on the NAND
85--------------------------------------
86To replace RedBoot with U-Boot, the easy way is to do this in linux.
87Start the kernel with the suggested options. Make sure to have set the
88mtdparts exactly as described, because this matches the layout on the
89mx35pdk.
90
91You should see in your boot log the following entries for the NAND
92flash:
93
945 cmdlinepart partitions found on MTD device mxc_nand
95Creating 5 MTD partitions on "mxc_nand":
960x000000000000-0x000000100000 : "boot"
970x000000100000-0x000000600000 : "linux"
980x000000600000-0x000006600000 : "root"
990x000006600000-0x000006e00000 : "cfg"
1000x000006e00000-0x000080000000 : "user"
101
102You can use the utilities flash_eraseall and nandwrite to put
103u-boot on the NAND. The bootloader is marked as "boot", and 1MB is
104reserved. If everything is correct, this partition is accessed as
105/dev/mtd4. However, check if it is correct with "cat /proc/mtd" and
106get the device node from the partition name:
107
108$ cat /proc/mtd | grep boot
109
110I suggest you try the utilities on a different partition to be sure
111if everything works correctly. If not, and you remove RedBoot, you have to
112reinstall it using the ATK tool as suggested by Freescale, or using a
113JTAG debugger.
114
115I report the versions of the utilities I used (they are provided with ELDK):
116
117-bash-3.2# nandwrite --version
118nandwrite $Revision: 1.32 $
119
120flash_eraseall --version
121flash_eraseall $Revision: 1.22 $
122
123nandwrite reports a warning if the file to be saved is not sector aligned.
124This should have no consequences, but I preferred to pad u-boot.bin
125to get no problem at all.
126$ dd if=/dev/zero of=zeros bs=1 count=74800
127$ cat u-boot.bin zeros > u-boot-padded.bin
128
129To erase the partition:
130$ flash_eraseall /dev/mtd4
131
132Writing u-boot:
133
134$ nandwrite /dev/mtd4 u-boot-padded.bin
135
136Now U-Boot is stored on the booting partition.
137
138To boot from NAND, you have to select the switches as follows:
139
140Personality board
141 SW2 1, 4, 5 on
142 2, 3, 6, 7, 8 off
143 SW1 all off
144
145Debug Board:
146 SW5 0
147 SW6 0
148 SW7 0
149 SW8 1
150 SW9 1
151 SW10 0
152
153
154Saving U-Boot in the NOR flash
155---------------------------------
156
157The procedure to save in the NOR flash is quite the same as to write into the NAND.
158
159Check the partition for boot in the NOR flash. Setting the mtdparts as reported,
160the boot partition should be /dev/mtd0.
161
162Creating 6 MTD partitions on "mxc_nor_flash.0":
1630x00000000-0x00080000 : "Bootloader"
1640x00080000-0x00480000 : "nor.Kernel"
1650x00480000-0x02280000 : "nor.userfs"
1660x02280000-0x03e80000 : "nor.rootfs"
1670x01fe0000-0x01fe3000 : "FIS directory"
1680x01fff000-0x04000000 : "Redboot config"
169
170To erase the whole partition:
171$ flash_eraseall /dev/mtd0
172
173Writing u-boot:
174dd if=u-boot.bin of=/dev/mtd0
175
176To boot from NOR, you have to select the switches as follows:
177
178Personality board
179 SW2 all off
180 SW1 all off
181
182Debug Board:
183 SW5 0
184 SW6 0
185 SW7 0
186 SW8 1
187 SW9 1
188 SW10 0