U-Boot
From Openmoko
Contents
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Phase0 Quick Start
- Make sure that your phone has had the battery and USB cable removed for at least 30 seconds.
- Connect the Neo (ie not Debug Board) to a Linux host with the USB cable.
- Hold in the AUX button on power-up to access the boot menu.
- Set the console to USB.
- Connect to /dev/ttyACM0 with a terminal program on the Linux host
- Note that the cdc_acm /dev/ttyACM0 access disappears as soon as the Neo boots, and is replaced by the cdc_ether usb0 network access.
- You're now at the bootloader prompt.
- Set the bootdelay uboot environment variable to -1 if you want it to always halt at the bootloader on power-up.
General
The GTA01 uses the u-boot bootloader.
More information on u-boot can be found at
- http://www.denx.de/wiki/DULG
- http://www.gumstix.org/tikiwiki/tiki-index.php?page=U-Boot
- http://linuxdevices.com/articles/AT5085702347.html
However, the vanilla u-boot doesn't support many of the features that GTA01 needs, such as
- Support for boot from NAND flash using S3C2410 Steppingstone
- Support for reading kernel/initrd from SD/Transflash
- Support for S3C2410 NAND flash
- Support for downloading programs via S3C2410 USB Device Controller
- Support to display bootup logo / status on S3C2410 Framebuffer
User:HaraldWelte is working on those issues, and in fact most of them have already been implemented.
Bootloader source code
The current bootloader patches can be found at http://svn.openmoko.org/trunk/src/target/u-boot/patches/.
Untar the sources, apply the patch. run "make gta01bv3_config" (or gta01bv2_config, or whatever hardware revision you have), run "make". You will get a resulting "u-boot.bin" image, which you can directly flash (either using existing bootloader or sjf2410-linux) into NAND.
Bootloader binary
The latest bootloader binary builds can be found at http://buildhost.openmoko.org/tmp/deploy/images/ . It should be written to the NAND flash address 0x00000000 (size 0x30000)
Bootloader development
QT2410
If you want to do bootloader development on the QT2410, it's easier to work with a bootloader image that can be downloaded via USB into RAM instead of flashing.
To do so, you need to edit the u-boot/include/configs/qt2410.h file, and change the "if 0" in Line 32 into a "if 1", then recompile with "make".
The resulting "u-boot.bin" is _NOT SUITABLE_ for NAND flash, but only for direct execution from within ram, e.g. by using the s3c2410_boot_usb program.
GTA01
Doing bootloader development on the GTA01 is a bit more tricky. first, we don't have any NOR flash. Second, there is no other way to boot _but_ from NAND. Therefore, we also don't have a USB downloader like the QT2410.
The main problem is: The S3C2410 Steppingstone unconditionally copies the first 4k of flash into its internal SRAM. That SRAM segment stays unconditionally mapped at physical address zero. How do we get around this
Using JTAG to boot from RAM
So how can we boot from RAM? We use JTAG / OpenOCD to
- reset and halt the cpu at PC=0
> reset halt target halted in ARM state due to debug request, current mode: Supervisor cpsr: 0x400000d3 pc: 0x00000000 MMU: disabled, D-Cache: disabled, I-Cache: disabled
- download a small piece of code for low-level SDRAM timing initialization (overwrite 4k SRAM of steppingstone)
> load_binary /space/misc/gta01/u-boot.git/foo.bin 0 downloaded 332 byte in 0s 21899us
- assert a break point at address 0x33f80000 (which indicates that the low-level code has finished)
> bp 0x33f80000 4 hw breakpoint added at address 0x33f80000
- run the code up to the break point
> resume Target 0 resumed > Target 0 halted target halted in ARM state due to breakpoint, current mode: Supervisor cpsr: 0x600000d3 pc: 0x33f80000 MMU: disabled, D-Cache: disabled, I-Cache: enabled
- download the u-boot RAM image to 0x33f80000
> load_binary /space/misc/gta01/u-boot.git/u-boot.bin 0x33f80000 downloaded 135692 byte in 6s 567264us
- resume processing
> resume Target 0 resumed
At this point, the display backlight gets bright and we see the following familiar prompt on the serial console:
U-Boot 1.1.6 (Jan 13 2007 - 23:44:23) DRAM: 128 MB NAND: 64 MiB *** Warning - bad CRC or NAND, using default environment In: serial Out: serial Err: serial Hit any key to stop autoboot: 0 GTA01Bv2 #
Creating bootable images
u-boot needs bootable images (such as kernels, but also initrd and others) in form of a so-called uImage. In order to create a uImage from e.g. a vmlinux kernel image, you can proceed as follows:
objcopy -O binary -R .note -R .comment -S vmlinux linux.bin gzip -9 linux.bin u-boot/tools/mkimage -A arm -O linux -T kernel -C gzip -a 30008000 -e 30008000 -n "Kernel Image QT2410" -d linux.bin.gz uImage
As of the Phase-0 release, our u-boot version now features an on-screen boot menu.
You can access the boot menu by pressing and holding the Neo1973 AUX button together with the power button while switching the phone on.
By pressing the Neo1973 AUX button you can cycle through the menu items. Use the POWER button to select one item.
You can add items to the boot menu by setting environment variables. The canonical form is menu_<number> <Title>: U-Boot-Commands
For example the following command will add a boot menu entry that switches to autofast charging and turns off the backlight:
setenv menu_6 Autofast-Charge and Backlight Off: neo1973 charger autofast\; neo1973 backlight off
Bootloader prompt
Accessing the bootloader prompt
The bootloader prompt is available either on the serial console (via Debug Board), or as virtual USB Serial device (USB CDC_ACM). Whether the serial port or usb i used depends on the u-boot environment variables stdin, stdout and stderr.
Whether or not you use usbtty, the first couple of messages will always be displayed on the serial console.
The bootloader is currently configured to waid for three seconds. If a key press on the stdin is received within those three seconds, auto-boot is aborted.
Using usbtty from Linux
Just by connecting the phone in u-boot mode to your Linux pc should make it detect a CDC ACM device, and you should get a new tty device called /dev/ttyACM0. Use your favourite terminal emulator (minicom, cu, zc, screen ...) to access it like any other serial port. If you don't have a favorite, try just
cu -l /dev/ttyACM0
First, you should try to check whether the USB device shows up in 'lsusb' while you're running in u-boot mode:
# lsusb -d 1457:5119 Bus 005 Device 079: ID 1457:5119
Second, lets see some more details about the available endpoints and configurations:
# lsusb -v -d 1457:5119 Bus 005 Device 079: ID 1457:5119 Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 2 Communications bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 16 idVendor 0x1457 idProduct 0x5119 bcdDevice 0.00 iManufacturer 1 OpenMoko, Inc iProduct 2 Neo1973 Bootloader U-Boot 1.2.0-g6c7cac8c-dirty-moko3 iSerial 3 0000000 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 85 bNumInterfaces 3 bConfigurationValue 1 iConfiguration 4 TTY via USB bmAttributes 0xc0 Self Powered MaxPower 0mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 2 Communications bInterfaceSubClass 2 Abstract (modem) bInterfaceProtocol 1 AT-commands (v.25ter) iInterface 6 Control Interface CDC Header: bcdCDC 0.6e CDC Call Management: bmCapabilities 0x00 bDataInterface 1 CDC ACM: bmCapabilities 0x00 CDC Union: bMasterInterface 0 bSlaveInterface 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0010 1x 16 bytes bInterval 255 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 10 CDC Data bInterfaceSubClass 0 Unused bInterfaceProtocol 0 iInterface 5 Bulk Data Interface Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0010 1x 16 bytes bInterval 255 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0010 1x 16 bytes bInterval 255 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 254 Application Specific Interface bInterfaceSubClass 1 Device Firmware Update bInterfaceProtocol 1 iInterface 7 USB Device Firmware Upgrade Device Status: 0x0001 Self Powered
Next, you can access it using your favourite terminal program.
Then, if the environment is not set correctly, you will need to use the current console (e.g. serial console) to set
GTA01Bv2 # setenv stderr usbtty GTA01Bv2 # setenv stdout usbtty GTA01Bv2 # setenv stdin usbtty
Typical u-boot prompt
U-Boot 1.2.0-moko1 (Feb 16 2007 - 00:36:13) DRAM: 128 MB NAND: 64 MiB Found Environment offset in OOB.. Video: 640x480x8 31kHz 59Hz USB: S3C2410 USB Deviced In: serial Out: serial Err: serial Hit any key to stop autoboot: 0 GTA01Bv3 #
Commands on the bootloader prompt
Auto-boot
Auto-boot executes the command[s] specified in the bootcmd environment variable. The default configuration is:
GTA01Bv3 # printenv bootcmd=setenv bootargs ${bootargs_base} ${mtdparts}; nand read.e 0x32000000 kernel; bootm 0x32000000
This basically tells us that it will load the content of the NAND partition kernel to memory address 0x32000000 and then try to boot it.
Environment
u-boot is configured to manage a non-volatile environment that is stored in NAND flash. You can use the commands to read/alter/store the environment in the following example:
GTA01Bv2 # printenv baudrate=115200 bootargs=rootfstype=jffs2 root=/dev/mtdblock4 console=ttySAC0,115200 console=tty0 loglevel=8 dyntick=enable lpj=252416 usbtty=cdc_acm bootdelay=10 stdout=serial stderr=serial stdin=serial mtdparts=mtdparts=neo1973-nand:0x00030000(u-boot),0x0000c000(u-boot_env),0x00200000(kernel),0x00130000(splash),0x03c94000(rootfs) mtdids=nand0=neo1973-nand bootargs_base=rootfstype=jffs2 root=/dev/mtdblock4 console=ttySAC0,115200 console=tty0 loglevel=8 dyntick=enable lpj=252416 bootcmd=setenv bootargs ${bootargs_base} ${mtdparts}; nand read.e 0x32000000 kernel; bootm 0x32000000 pcf50606_int1=0x40 filesize=160C000 partition=nand0,0 mtddevnum=0 mtddevname=u-boot Environment size: 670/16380 bytes GTA01Bv3 # setenv bootdelay 10 GTA01Bv3 # printenv bootdelay bootdelay=10 GTA01Bv3 # saveenv Saving Environment to NAND... Erasing Nand...Writing to Nand... done GTA01Bv3 #
Note: When setting multiple commands, e.g. for bootcmd, you need to escape the ';', for instance
GTA01Bv3 # setenv bootcmd mmcinit\; ext2load mmc 0 0x32000000 uImage\; bootm 0x32000000
MMC/SD
in order to initialize a MMC/SD card, you have to use the ``mmcinit command.
GTA01Bv3 # mmcinit trying to detect SD Card... MMC found. Card desciption is: Manufacturer ID = 58d564 HW/FW Revision = 3 8 Product Name = 21DN!@X� Serial Number = 445303 Month = 5 Year = 2000 READ_BL_LEN=15, C_SIZE_MULT=7, C_SIZE=3197 size = 4208984064 GTA01Bv3 #
afterwards, you can read ext2 filesystems like:
GTA01Bv3 # ext2ls mmc 0 <DIR> 1024 . <DIR> 1024 .. <DIR> 12288 lost+found 1544788 uImage
NAND
GTA01Bv3 # help nand nand info - show available NAND devices nand device [dev] - show or set current device nand read[.jffs2] - addr off size nand write[.jffs2] - addr off size - read/write `size' bytes starting at offset `off' to/from memory address `addr' nand erase [clean] [off size] - erase `size' bytes from offset `off' (entire device if not specified) nand bad - show bad blocks nand dump[.oob] off - dump page nand scrub - really clean NAND erasing bad blocks (UNSAFE) nand markbad off - mark bad block at offset (UNSAFE) nand biterr off - make a bit error at offset (UNSAFE)
Loading Kernel from NAND
GTA01Bv3 # nand read 0x32000000 kernel NAND read: device 0 offset 212992, size 2097152 ... 2097152 bytes read: OK GTA01Bv3 # bootm 0x32000000 ## Booting image at 32000000 ... Image Name: OpenMoko Kernel Image Neo1973 Created: 2007-02-15 23:54:18 UTC Image Type: ARM Linux Kernel Image (gzip compressed) Data Size: 1546258 Bytes = 1.5 MB Load Address: 30008000 Entry Point: 30008000 Verifying Checksum ... OK Uncompressing Kernel Image ... OK Starting kernel ...
Writing new bootloader to NAND
The following set of commands loads the file u-boot.bin from ext2/mmc and flashes it into the bootloader flash partition:
GTA01Bv3 # ext2load mmc 0 0x32000000 u-boot.bin GTA01Bv3 # nand erase u-boot GTA01Bv3 # nand write.e 0x32000000 u-boot ${filesize}
Writing kernel to NAND
The following set of commands loads the file uImage from ext2/mmc and flashes it into the kernel flash partition:
GTA01Bv3 # ext2load mmc 0 0x32000000 uImage GTA01Bv3 # nand erase kernel GTA01Bv3 # nand write.e 0x32000000 kernel ${filesize}
Writing rootfs to NAND
The following set of commands loads the file rootfs.jffs2 from ext2/mmc and flashes it into the rootfs flash partition:
GTA01Bv3 # ext2load mmc 0 0x32000000 rootfs.jffs2 GTA01Bv3 # nand erase rootfs GTA01Bv3 # nand write.e 0x32000000 rootfs ${filesize}
Please note that this will only work with root file system sizes that are smaller than the amount of memory above 0x32000000, which in the case of 64MB SDRAM is something like 32MB.
Our version of u-boot supports a couple of Neo1973 specific commands:
GTA01Bv2 # help neo1973 neo1973 neo1973 info - display phone informantion neo1973 power-off - switch off the phone neo1973 charger status - display charger status neo1973 charger autofast - enable automatic fast (500mA) charging neo1973 charger !autofast - disable automatic fast (500mA) charging neo1973 charger fast - enable fast (500mA) charging neo1973 charger off - disable charging neo1973 backlight (on|off) - switch backlight on or off neo1973 vibrator (on|off) - switch vibrator on or off
Power-off
Using
neo1973 power-off
you can switch the device off from the bootloader prompt.
For a detailed description of the charger basics, see Neo1973 Battery Charger.
Inquiring the charger state
You can get the current charger status by issuing
neo1973 charger status
The following modes are possible:
- idle - no charging
- trickle - FIXME
- pre - Slow (100mA) charging, works in hardware.
- fast_cccv - Fast (500mA) charging, using Constant-Current followed by Constant Voltage (Li-Ion)
Disabling battery charging
You can disable battery charging (until the next reboot) by issuing
neo1973 charger off
Forcing fast charge
Using
neo1973 charger fast
you can force the PMU to try to do a fast (500mA) charge of the battery. It will abort if the battery is in over temperature or some other error condition occurs.
Enabling / Disabling automatic fast charge
Autofast is a feature of the PCF50606 PMU. It means that the fast_cccv mode will be automatically selected if a charger with suitable voltage is plugged in, and the battery not in over temperature condition.
WARNING: This is potentially dangerous. Only enable autofast if you ARE SURE that you can draw 500mA from the USB connector. This is the case with a wall outlet charger, or if you are attached to a self-powered hub or a desktop PC root hub. Bus powered hubs and some laptops only provide 100mA on their USB ports and can thus not support fast charging |
You can enable or disable autofast by
neo1973 charger autofast
and
neo1973 charger !autofast
respectively.
Backlight
You can switch the backlight on and off by using
neo1973 backlight on
and
neo1973 backlight off
respectively.
Vibrator
You can switch the vibrator on and off by using
neo1973 vibrator on
and
neo1973 vibrator off
respectively.
S3C2410 specific commands
GTA01Bv2 # help s3c2410 s3c2410 speed get - display current PLL speed config s3c2410 speed list - display supporte PLL speed configs s3c2410 speed set - set PLL speed GTA01Bv2 # s3c2410 speed list 50 MHz 101 MHz 202 MHz 266 MHz GTA01Bv2 # s3c2410 speed get FCLK = 202 MHz, HCLK = 101 MHz, PCLK = 50 MHz GTA01Bv2 # s3c2410 speed set 101 GTA01Bv2 # s3c2410 speed get FCLK = 101 MHz, HCLK = 50 MHz, PCLK = 50 MHz
266MHz clock
You can re-configure the S3C2410 PLL to generate a 266 MHz core cpu clock (rather than the 200MHz default) by using
GTA01Bv2 # s3c2410 speed set 266
and
GTA01Bv2 # s3c2410 speed set 202
respectively.
WARNING: The current hardware (as of GTA01Bv3) only runs stable at 266MHz if you do not attach anything (esp. the FPC / Debug Board to the Debug Port |
TFTP on QT2410
The QT2410 cs8900a Ethernet can be used to download images via network.
First, you have to make sure that ipaddr, serverip, ethaddr' and netmaskk are set correctly in the environment:
QT2410 # printenv ethaddr=00:01:02:03:04:05 netmask=255.255.255.0 ipaddr=192.168.100.100 serverip=192.168.100.1
TFTP kernel download
QT2410 # tftpboot 0x32000000 *** Warning: no boot file name; using 'C0A86464.img' TFTP from server 192.168.100.1; our IP address is 192.168.100.100 Filename 'C0A86464.img'. Load address: 0x32000000 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ########################################## done Bytes transferred = 1544788 (179254 hex)
you can then commence booting via
QT2410# bootm 0x32000000
Device Firmware Upgrade
Our version of u-boot also implements USB DFU. This can be useful to load files and kernel for quick testing.
To find out whether your version of u-boot supports this, use the output of
$ lsusb -v -d 1457:5119
while the phone is in u-boot mode.
If it supports DFU, you should see the following snippet towards the end of the output:
Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 254 Application Specific Interface bInterfaceSubClass 1 Device Firmware Update bInterfaceProtocol 1 iInterface 0
For information on how to do firmware upgrades, please see dfu-util.
Booting files over DFU
To load a file at memory address 0x32000000:
dfu-util -a 0 -D fileToLoad -R
After that, send 'bootm 0x32000000' to u-boot or 'bootelf 0x32000000' if its an elf file.
Simple python script that can boot an ELF image - avoiding a ACM bug that breaks on large packets.
#!/usr/bin/python import sys import os import time cmd1 = "neo backlight off\n" cmd2 = "bootelf 0x32000000\n" def output(tty, str): for x in str: tty.write(x) tty.flush() if len(sys.argv) == 2: print "Loading %s..." % sys.argv[1] loadfile = "dfu-util -a 0 -D %s -R" % sys.argv[1] os.system(loadfile) time.sleep(3) tty = open("/dev/ttyACM0", "a") output(tty, cmd1) output(tty, cmd2) tty.close() else: print "Usage: %s elffile" % sys.argv[0] print "" sys.exit(2)
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