mirror of
https://github.com/smaeul/u-boot.git
synced 2025-11-03 21:48:15 +00:00
a187559e3d
Correct spelling of "U-Boot" shall be used in all written text (documentation, comments in source files etc.). Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Heiko Schocher <hs@denx.de> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
141 lines
3.8 KiB
Plaintext
141 lines
3.8 KiB
Plaintext
U-Boot for Freescale i.MX6
|
|
|
|
This file contains information for the port of U-Boot to the Freescale i.MX6
|
|
SoC.
|
|
|
|
1. CONVENTIONS FOR FUSE ASSIGNMENTS
|
|
-----------------------------------
|
|
|
|
1.1 MAC Address: It is stored in fuse bank 4, with the 32 lsbs in word 2 and the
|
|
16 msbs in word 3[15:0].
|
|
For i.MX6SX and i.MX6UL, they have two MAC addresses. The second MAC address
|
|
is stored in fuse bank 4, with the 16 lsb in word 3[31:16] and the 32 msbs in
|
|
word 4.
|
|
|
|
Example:
|
|
|
|
For reading the MAC address fuses on a MX6Q:
|
|
|
|
- The MAC address is stored in two fuse addresses (the fuse addresses are
|
|
described in the Fusemap Descriptions table from the mx6q Reference Manual):
|
|
|
|
0x620[31:0] - MAC_ADDR[31:0]
|
|
0x630[15:0] - MAC_ADDR[47:32]
|
|
|
|
In order to use the fuse API, we need to pass the bank and word values, which
|
|
are calculated as below:
|
|
|
|
Fuse address for the lower MAC address: 0x620
|
|
Base address for the fuses: 0x400
|
|
|
|
(0x620 - 0x400)/0x10 = 0x22 = 34 decimal
|
|
|
|
As the fuses are arranged in banks of 8 words:
|
|
|
|
34 / 8 = 4 and the remainder is 2, so in this case:
|
|
|
|
bank = 4
|
|
word = 2
|
|
|
|
And the U-Boot command would be:
|
|
|
|
=> fuse read 4 2
|
|
Reading bank 4:
|
|
|
|
Word 0x00000002: 9f027772
|
|
|
|
Doing the same for the upper MAC address:
|
|
|
|
Fuse address for the upper MAC address: 0x630
|
|
Base address for the fuses: 0x400
|
|
|
|
(0x630 - 0x400)/0x10 = 0x23 = 35 decimal
|
|
|
|
As the fuses are arranged in banks of 8 words:
|
|
|
|
35 / 8 = 4 and the remainder is 3, so in this case:
|
|
|
|
bank = 4
|
|
word = 3
|
|
|
|
And the U-Boot command would be:
|
|
|
|
=> fuse read 4 3
|
|
Reading bank 4:
|
|
|
|
Word 0x00000003: 00000004
|
|
|
|
,which matches the ethaddr value:
|
|
=> echo ${ethaddr}
|
|
00:04:9f:02:77:72
|
|
|
|
Some other useful hints:
|
|
|
|
- The 'bank' and 'word' numbers can be easily obtained from the mx6 Reference
|
|
Manual. For the mx6quad case, please check the "46.5 OCOTP Memory Map/Register
|
|
Definition" from the "i.MX 6Dual/6Quad Applications Processor Reference Manual,
|
|
Rev. 1, 04/2013" document. For example, for the MAC fuses we have:
|
|
|
|
Address:
|
|
21B_C620 Value of OTP Bank4 Word2 (MAC Address)(OCOTP_MAC0)
|
|
|
|
21B_C630 Value of OTP Bank4 Word3 (MAC Address)(OCOTP_MAC1)
|
|
|
|
- The command '=> fuse read 4 2 2' reads the whole MAC addresses at once:
|
|
|
|
=> fuse read 4 2 2
|
|
Reading bank 4:
|
|
|
|
Word 0x00000002: 9f027772 00000004
|
|
|
|
2. Using imx_usb_loader for first install with SPL
|
|
--------------------------------------------------
|
|
|
|
imx_usb_loader is a very nice tool by BoundaryDevice that
|
|
allow to install U-Boot without a JTAG debugger, using
|
|
the USB boot mode as described in the manual. It is
|
|
a replacement for Freescale's MFGTOOLS.
|
|
|
|
The sources can be found here:
|
|
|
|
https://github.com/boundarydevices/imx_usb_loader.git
|
|
|
|
Booting in USB mode, the i.MX6 announces itself to the Linux Host as:
|
|
|
|
Bus 001 Device 111: ID 15a2:0061 Freescale Semiconductor, Inc.
|
|
|
|
imx_usb_loader is able to download a single file (u-boot.imx)
|
|
to the board. For boards without SPL support, it is enough to
|
|
issue the command:
|
|
|
|
sudo ../imx_usb_loader/imx_usb -v u-boot.imx
|
|
|
|
Getting U-Boot when SPL support is active, it requires
|
|
two downloads. imx_usb_loader downloads the SPL into
|
|
OCRAM and starts it. SPL will check for a valid u-boot.img, and
|
|
because it is not found, it will wait for it using the y-modem
|
|
protocol via the console.
|
|
|
|
A first install is then possible by combining imx_usb_loader with
|
|
another tool such as kermit.
|
|
|
|
sudo ../imx_usb_loader/imx_usb -v SPL
|
|
kermit kermit_uboot
|
|
|
|
and kermit_uboot contains something like this (set line should be adjusted):
|
|
|
|
set line /dev/ttyUSB1
|
|
set speed 115200
|
|
SET CARRIER-WATCH OFF
|
|
set flow-control none
|
|
set handshake none
|
|
set prefixing all
|
|
set file type bin
|
|
set protocol ymodem
|
|
send u-boot.img
|
|
c
|
|
|
|
The last "c" command tells kermit (from ckermit package in most distros)
|
|
to switch from command line mode to communication mode, and when the
|
|
script is finished, the U-Boot prompt is shown in the same shell.
|