Difference between revisions of "Flameman/dht-walnut/firmware"

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(Firnware Bootloaders)
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Line 1: Line 1:
= Firnware Bootloaders =
+
= Firmware Bootloaders =
  
 
* ppcboot (not suggested)
 
* ppcboot (not suggested)
 
* U-Boot (it can't load kernel >=2.5.25)
 
* U-Boot (it can't load kernel >=2.5.25)
* U-Boot-kanojio (under development, it will be able to boot kernel >2.6.25, see below)
+
* U-Boot-kanojio (it's able to boot kernel >2.6.25 from {scsi, pata, sata, firewire, usb, net})
  
  
 +
status:
 +
* uboot-1.2.0-kanojo: under development
 +
* uboot-1.2.0-hack-new: tftpboot is working with ramrootfs, ide is working
 +
* uboot-2009: tftpboot is working with ramrootfs, ide is not working, eth0 issued, tftpboot issued with a download > 6Mb ... aborted at all
  
  
Line 348: Line 352:
  
  
download
 
  
crc (40000) = 3aae52fa
+
there are problem to upload file to this wiki, email me if you need uboot, i will send you by email
 +
 
 +
 
  
 
=== issues ===
 
=== issues ===
Line 356: Line 361:
 
<pre>
 
<pre>
  
...
+
this setion need to be updated
  
 
</pre>
 
</pre>
Line 362: Line 367:
 
== uboot-2009 (not mature, not good, under development) ==
 
== uboot-2009 (not mature, not good, under development) ==
  
it's under development, it will released soon
+
it was under development, i will not released: too many issue, aborted
 +
 
 +
== uboot problem with kernel >=2.6.25, ARCH=POWERPC ==
 +
 
 +
<pre>
 +
Based on kernel version 2.6.32. Page generated on 2009-12-11 16:23 EST.
 +
 
 +
1 The PowerPC boot wrapper
 +
2 ------------------------
 +
3
 +
4
 +
5 PowerPC image targets compresses and wraps the kernel image (vmlinux) with
 +
6 a boot wrapper to make it usable by the system firmware.  There is no
 +
7 standard PowerPC firmware interface, so the boot wrapper is designed to
 +
8 be adaptable for each kind of image that needs to be built.
 +
9
 +
10 The boot wrapper can be found in the arch/powerpc/boot/ directory.  The
 +
11 Makefile in that directory has targets for all the available image types.
 +
12 The different image types are used to support all of the various firmware
 +
13 interfaces found on PowerPC platforms.  OpenFirmware is the most commonly
 +
14 used firmware type on general purpose PowerPC systems from Apple, IBM and
 +
15 others.  U-Boot is typically found on embedded PowerPC hardware, but there
 +
16 are a handful of other firmware implementations which are also popular.  Each
 +
17 firmware interface requires a different image format.
 +
18
 +
19 The boot wrapper is built from the makefile in arch/powerpc/boot/Makefile and
 +
20 it uses the wrapper script (arch/powerpc/boot/wrapper) to generate target
 +
21 image.  The details of the build system is discussed in the next section.
 +
22 Currently, the following image format targets exist:
 +
23
 +
24   cuImage.%: Backwards compatible uImage for older version of
 +
25 U-Boot (for versions that don't understand the device
 +
26 tree).  This image embeds a device tree blob inside
 +
27 the image.  The boot wrapper, kernel and device tree
 +
28 are all embedded inside the U-Boot uImage file format
 +
29 with boot wrapper code that extracts data from the old
 +
30 bd_info structure and loads the data into the device
 +
31 tree before jumping into the kernel.
 +
32   Because of the series of #ifdefs found in the
 +
33 bd_info structure used in the old U-Boot interfaces,
 +
34 cuImages are platform specific.  Each specific
 +
35 U-Boot platform has a different platform init file
 +
36 which populates the embedded device tree with data
 +
37 from the platform specific bd_info file.  The platform
 +
38 specific cuImage platform init code can be found in
 +
39 arch/powerpc/boot/cuboot.*.c.  Selection of the correct
 +
40 cuImage init code for a specific board can be found in
 +
41 the wrapper structure.
 +
42   dtbImage.%: Similar to zImage, except device tree blob is embedded
 +
43 inside the image instead of provided by firmware.  The
 +
44 output image file can be either an elf file or a flat
 +
45 binary depending on the platform.
 +
46   dtbImages are used on systems which do not have an
 +
47 interface for passing a device tree directly.
 +
48 dtbImages are similar to simpleImages except that
 +
49 dtbImages have platform specific code for extracting
 +
50 data from the board firmware, but simpleImages do not
 +
51 talk to the firmware at all.
 +
52   PlayStation 3 support uses dtbImage.  So do Embedded
 +
53 Planet boards using the PlanetCore firmware.  Board
 +
54 specific initialization code is typically found in a
 +
55 file named arch/powerpc/boot/<platform>.c; but this
 +
56 can be overridden by the wrapper script.
 +
57   simpleImage.%: Firmware independent compressed image that does not
 +
58 depend on any particular firmware interface and embeds
 +
59 a device tree blob.  This image is a flat binary that
 +
60 can be loaded to any location in RAM and jumped to.
 +
61 Firmware cannot pass any configuration data to the
 +
62 kernel with this image type and it depends entirely on
 +
63 the embedded device tree for all information.
 +
64   The simpleImage is useful for booting systems with
 +
65 an unknown firmware interface or for booting from
 +
66 a debugger when no firmware is present (such as on
 +
67 the Xilinx Virtex platform).  The only assumption that
 +
68 simpleImage makes is that RAM is correctly initialized
 +
69 and that the MMU is either off or has RAM mapped to
 +
70 base address 0.
 +
71   simpleImage also supports inserting special platform
 +
72 specific initialization code to the start of the bootup
 +
73 sequence.  The virtex405 platform uses this feature to
 +
74 ensure that the cache is invalidated before caching
 +
75 is enabled.  Platform specific initialization code is
 +
76 added as part of the wrapper script and is keyed on
 +
77 the image target name.  For example, all
 +
78 simpleImage.virtex405-* targets will add the
 +
79 virtex405-head.S initialization code (This also means
 +
80 that the dts file for virtex405 targets should be
 +
81 named (virtex405-<board>.dts).  Search the wrapper
 +
82 script for 'virtex405' and see the file
 +
83 arch/powerpc/boot/virtex405-head.S for details.
 +
84   treeImage.%; Image format for used with OpenBIOS firmware found
 +
85 on some ppc4xx hardware.  This image embeds a device
 +
86 tree blob inside the image.
 +
87   uImage: Native image format used by U-Boot.  The uImage target
 +
88 does not add any boot code.  It just wraps a compressed
 +
89 vmlinux in the uImage data structure.  This image
 +
90 requires a version of U-Boot that is able to pass
 +
91 a device tree to the kernel at boot.  If using an older
 +
92 version of U-Boot, then you need to use a cuImage
 +
93 instead.
 +
94   zImage.%: Image format which does not embed a device tree.
 +
95 Used by OpenFirmware and other firmware interfaces
 +
96 which are able to supply a device tree.  This image
 +
97 expects firmware to provide the device tree at boot.
 +
98 Typically, if you have general purpose PowerPC
 +
99 hardware then you want this image format.
 +
100
 +
101 Image types which embed a device tree blob (simpleImage, dtbImage, treeImage,
 +
102 and cuImage) all generate the device tree blob from a file in the
 +
103 arch/powerpc/boot/dts/ directory.  The Makefile selects the correct device
 +
104 tree source based on the name of the target.  Therefore, if the kernel is
 +
105 built with 'make treeImage.walnut simpleImage.virtex405-ml403', then the
 +
106 build system will use arch/powerpc/boot/dts/walnut.dts to build
 +
107 treeImage.walnut and arch/powerpc/boot/dts/virtex405-ml403.dts to build
 +
108 the simpleImage.virtex405-ml403.
 +
109
 +
110 Two special targets called 'zImage' and 'zImage.initrd' also exist.  These
 +
111 targets build all the default images as selected by the kernel configuration.
 +
112 Default images are selected by the boot wrapper Makefile
 +
113 (arch/powerpc/boot/Makefile) by adding targets to the $image-y variable.  Look
 +
114 at the Makefile to see which default image targets are available.
 +
115
 +
116 How it is built
 +
117 ---------------
 +
118 arch/powerpc is designed to support multiplatform kernels, which means
 +
119 that a single vmlinux image can be booted on many different target boards.
 +
120 It also means that the boot wrapper must be able to wrap for many kinds of
 +
121 images on a single build.  The design decision was made to not use any
 +
122 conditional compilation code (#ifdef, etc) in the boot wrapper source code.
 +
123 All of the boot wrapper pieces are buildable at any time regardless of the
 +
124 kernel configuration.  Building all the wrapper bits on every kernel build
 +
125 also ensures that obscure parts of the wrapper are at the very least compile
 +
126 tested in a large variety of environments.
 +
127
 +
128 The wrapper is adapted for different image types at link time by linking in
 +
129 just the wrapper bits that are appropriate for the image type.  The 'wrapper
 +
130 script' (found in arch/powerpc/boot/wrapper) is called by the Makefile and
 +
131 is responsible for selecting the correct wrapper bits for the image type.
 +
132 The arguments are well documented in the script's comment block, so they
 +
133 are not repeated here.  However, it is worth mentioning that the script
 +
134 uses the -p (platform) argument as the main method of deciding which wrapper
 +
135 bits to compile in.  Look for the large 'case "$platform" in' block in the
 +
136 middle of the script.  This is also the place where platform specific fixups
 +
137 can be selected by changing the link order.
 +
138
 +
139 In particular, care should be taken when working with cuImages.  cuImage
 +
140 wrapper bits are very board specific and care should be taken to make sure
 +
141 the target you are trying to build is supported by the wrapper bits.
 +
</pre>
 +
 
 +
 
 +
=== solution & issues ===
 +
 
 +
"uboot requires a version of U-Boot that is able to pass a device tree to the kernel at boot" 
 +
"If using an older version of U-Boot, then you need to use a cuImage instead"
 +
 
 +
1) which uboot version is able to boot new style uImage ?
 +
2) what about the porting of the IDE support for dht-walnut to newer uBoot ?
 +
3) what about the tftp buffer overflow bug ?
  
status:
 
* uboot-1.2.0-hack-new: tftpboot is working with ramrootfs, ide is working
 
* uboot-2009: tftpboot is working with ramrootfs, ide is not working, eth0 issued, tftpboot issued with a download > 6Mb
 
  
 +
kanojio-2n-stage-kexecboot loader has been developed for ARM, but it is also fixing the dht-walnut boot issues
  
 
== uboot-kanojio ==
 
== uboot-kanojio ==
Line 470: Line 631:
  
 
i will release as soon as possible
 
i will release as soon as possible
 +
 +
 +
[[Category:DHT-Walnut]]

Latest revision as of 04:36, 13 April 2011

Firmware Bootloaders

  • ppcboot (not suggested)
  • U-Boot (it can't load kernel >=2.5.25)
  • U-Boot-kanojio (it's able to boot kernel >2.6.25 from {scsi, pata, sata, firewire, usb, net})


status:

  • uboot-1.2.0-kanojo: under development
  • uboot-1.2.0-hack-new: tftpboot is working with ramrootfs, ide is working
  • uboot-2009: tftpboot is working with ramrootfs, ide is not working, eth0 issued, tftpboot issued with a download > 6Mb ... aborted at all



download the latest uboot tested firmware

uboot-dht-walnut-install-kit.tgz


U-Boot 1.1.4

!!!NOTE!!! uboot-v1.1.4 has an issue with tftp-boot ramrootfs, but it works well with disk-boot, you'd better use uboot-v1.2 for a good firmware replacement: good and solid rock state out of my tests !



uboot is a significantly updated replacement for ppcboot. U-Boot for the DHT-Walnut DENX U-Boot and Linux Guide for Walnut

Changes since u-boot-1.1.4-df1.bin:

  • A default ethaddr is now set: de:ad:be:ef:00:00
  • The ethaddr can be changed as often as you like. Use: setenv ethaddr be:ef:be:ef:be:ef ; saveenv
  • Only the first two memory banks of a DIMM are used. This allows us to use (half of) double-sided DIMMS.

Some things to note when changing from ppcboot to U-Boot:

  • Default baudrate is 115200.
  • Occupies flash addresses 0xfffc0000-0xffffffff
  • Maintains two copies of environment data, primary copy at 0xfffb0000, backup copy at 0xfffa0000.

Installing

  • Boot the board and bring it to the ppcboot (or U-Boot) console prompt.
  • Download the new bootloader u-boot-1.1.4-df2.bin into RAM:

(1) Using Kermit (you'll need a terminal emulator that supports the kermit file transfer mode): loadb 800000 115200

  • Switch baudrate to 115200 bps and press ENTER ...
  • Ready for binary (kermit) download ...
  • Start Addr=0x00800000
  • Switch baudrate to 9600 bps and press ESC ...

(2) Using tftpboot (requires a tftp server and setting the environment variables ethaddr, ipaddr and serverip)

  • tftpboot 800000 u-boot-1.1.4-df2.bin Using ppc_4xx_eth0 device
* TFTP from server 192.168.1.1; our IP address is 192.168.1.2
* Filename 'u-boot.bin'.
* Load address: 0x800000
* Loading: done
* Bytes transferred = 262144 (40000 hex)
  • Verify that the download was received correctly (crc should be 0xd3cef189):
  • crc 800000 40000
  • CRC32 for 00800000 ... 0083ffff ==> d3cef189
  • Unprotect the last 4 sectors:
  • protect off fffc0000 ffffffff
  • Un-Protected 4 sectors

From this point on, do *not* power down the board, and type *very* carefully. This is the critical section.

  • Erase the last four sectors:
  • erase fffc0000 ffffffff
* Erase Flash from 0xfffc0000 to 0xffffffff
* Erasing sector fffc0000
* Erasing sector fffd0000
* Erasing sector fffe0000
* Erasing sector ffff0000
* done
* Erased 4 sectors
  • Copy the new bootloader into flash:
  • cp.b 800000 fffc0000 40000
* Copy to Flash... done
  • Verify that the image is correct (crc of u-boot-1.1.4-df2.bin is 0xd3cef189).
  • crc fffc0000 40000
* CRC32 for fffc0000 ... ffffffff ==> d3cef189

End of critical section. Congratulations!

  • Reset the board and see that the new version booted!
  • Don't forget to change your baud rate to 115200!
  • reset

You will see a message like : *** Warning - bad CRC, using default environment. That's normal. It will go away after you issue a saveenv command.

ppcboot 1.1.6

the latest ported ppcboot is 1.1.6, it need a patch and it will build for flashing at 0xfff80000 as a replacement for the pcboot-1.1.2 that comes with the board.


Installing

Quick notes on installing ppcboot v1.1.6.1

  • Boot the board and bring it to the ppcboot console prompt.
  • Check current flash configuration:

=> flinfo

Bank # 1: AMD AM29F040 (512 Kbit, uniform sector size)
  Size: 512 KB in 8 Sectors
  Sector Start Addresses:
    FFF80000  RO  FFF90000  RO  FFFA0000  RO  FFFB0000      FFFC0000
    FFFD0000      FFFE0000      FFFF0000     


Note that the bottom three sectors, containing the existing 1.1.2 bootloader, are protected. We also want to protect the last sector, which contains the initial jump instruction, so:

=> protect on ffff0000 ffffffff

Protected 1 sectors
  • Zero out a section of ram before the download:

=> mw.b 400000 0 30000

  • Now download the new bootloader ppcboot1.1.6.1.bin into ram (you'll need a terminal emulator that supports the kermit file transfer mode):

=> loadb 400000 115200

## Switch baudrate to 115200 bps and press ENTER ...
## Ready for binary (kermit) download ...
## Start Addr      = 0x00400000
## Switch baudrate to 9600 bps and press ESC ...
  • Verify that the download was received correctly (crc should be 0x083fb0a3):

=> crc 400000 30000

CRC32 for 00400000 ... 0042ffff ==> 083fb0a3
  • Erase the three spare sectors, which we'll use to backup the 1.1.2 bootloader:

=> erase fffc0000 fffeffff

Erase Flash from 0xfffc0000 to 0xfffeffff
Erasing sector fffc0000
.Erasing sector fffd0000
.Erasing sector fffe0000
. done
Erased 3 sectors
  • (Optional: erase the 0xfffb0000 sector, which will be used for non-volatile environment storage.)

=> erase fffb0000 fffbffff

Erase Flash from 0xfffb0000 to 0xfffbffff
Erasing sector fffb0000
. done
Erased 1 sectors
  • Check that sectors 0xfffc0000 to 0xfffe0000 are erased, and sector 0xffff0000 is protected:

=> flinfo

Bank # 1: AMD AM29F040 (512 Kbit, uniform sector size)
  Size: 512 KB in 8 Sectors
  Sector Start Addresses:
    FFF80000  RO  FFF90000  RO  FFFA0000  RO  FFFB0000 E    FFFC0000 E
    FFFD0000 E    FFFE0000 E    FFFF0000  RO 
  • Now we're ready to backup the 1.1.2 bootloader. Copy three sectors from 0xfff80000 to 0xfffc0000:

=> cp.b fff80000 fffc0000 30000

Copy to Flash... done
  • Easy enough, right? Compare just to be sure it went ok:

=> cmp.b fff80000 fffc0000 30000

Total of 196608 bytes were the same
  • Now we're ready to modify the bootsectors. We'll turn off protection, erase the three bottom sectors, and copy the new 1.1.6.1 bootloader from ram.
  • Unprotect the bottom three sectors:

=> protect off fff80000 fffaffff

Un-Protected 3 sectors

From this point on, do *not* power down the board. This is the critical section.

  • Erase the bottom three sectors with the original 1.1.2 bootloader:

=> erase fff80000 fffaffff

Erase Flash from 0xfff80000 to 0xfffaffff
Erasing sector fff80000
.Erasing sector fff90000
.Erasing sector fffa0000
. done
Erased 3 sectors
  • Copy the new bootloader into flash:

=> cp.b 400000 fff80000 30000

Copy to Flash... done
  • Verify the copy:

=> cmp.b 400000 fff80000 30000

Total of 196608 bytes were the same
  • Verify that the image is correct (crc of ppcboot1.1.6.1.bin is 0x083fb0a3).

=> crc fff80000 30000

CRC32 for fff80000 ... fffaffff ==> 083fb0a3

End of critical section. Congratulations'

  • We've finished modifying flash, so turn the write protection back on:

=> protect on fff80000 fffaffff

Protected 3 sectors
  • Reset the board and see that the new version booted

=> reset

PPCBoot 1.1.6 (Feb  5 2006 - 21:38:51)

CPU:   IBM PowerPC 405GP Rev. E at 266.640 MHz (PLB=66, OPB=33, EBC=33 MHz)
           PCI async ext clock used, internal PCI arbiter enabled
           16 kB I-Cache 8 kB D-Cache


To sum up, you'll end up executing these commands:

=> protect on ffff0000 ffffffff

=> mw.b 400000 0 30000

=> loadb 400000 115200

=> crc 400000 30000

=> erase fffc0000 fffeffff

=> cp.b fff80000 fffc0000 30000

=> cmp.b fff80000 fffc0000 30000

=> protect off fff80000 fffaffff

=> erase fff80000 fffaffff

=> cp.b 400000 fff80000 30000

=> cmp.b 400000 fff80000 30000

=> crc fff80000 30000

=> protect on fff80000 fffaffff

new firmware, uboot-v1.2-hack (the most mature i suggest)

brief about how to install on flash


=> printenv
stdin=serial
stdout=serial
stderr=serial
...

=> setenv baudrate 9600
=> setenv loads_echo 1
=> ethaddr DE:AD:BE:EF:DE:AD
=> ethaddr serverip 192.168.1.14
=> ethaddr ipaddr 192.168.1.2
=> tftpboot 800000 uboot-v1.2.img
TFTP from server 192.168.1.14; our IP address is 192.$
Filename 'uboot-v1.2.img'.
Load address: 0x800000
Loading: *^H#########################################$
done
Bytes transferred = 262144 (40000 hex)

=> crc 800000 40000
CRC32 for 00800000 ... 0083ffff ==> 3aae52fa

=> protect off fffc0000 ffffffff
Un-Protected 4 sectors

=> erase fffc0000 ffffffff
Erase Flash from 0xfffc0000 to 0xffffffff
Erasing sector fffc0000
.Erasing sector fffd0000
.Erasing sector fffe0000
.Erasing sector ffff0000
. done
Erased 4 sectors

=> cp.b 800000 fffc0000 40000
Copy to Flash... done

=> crc fffc0000 40000
CRC32 for fffc0000 ... ffffffff ==> 3aae52fa

=> protect on fffc0000 ffffffff
=> reset

brief about set baud and env

# setenv baudrate 9600
## Switch baudrate to 9600 bps and press ENTER ...

# saveenv
Saving Environment to Flash...
Un-Protected 1 sectors
Un-Protected 1 sectors
Erasing Flash...
. done
Erased 1 sectors
Writing to Flash... done
Protected 1 sectors
Protected 1 sectors


there are problem to upload file to this wiki, email me if you need uboot, i will send you by email


issues


this setion need to be updated

uboot-2009 (not mature, not good, under development)

it was under development, i will not released: too many issue, aborted

uboot problem with kernel >=2.6.25, ARCH=POWERPC

Based on kernel version 2.6.32. Page generated on 2009-12-11 16:23 EST.

1	The PowerPC boot wrapper
2	------------------------
3	
4	
5	PowerPC image targets compresses and wraps the kernel image (vmlinux) with
6	a boot wrapper to make it usable by the system firmware.  There is no
7	standard PowerPC firmware interface, so the boot wrapper is designed to
8	be adaptable for each kind of image that needs to be built.
9	
10	The boot wrapper can be found in the arch/powerpc/boot/ directory.  The
11	Makefile in that directory has targets for all the available image types.
12	The different image types are used to support all of the various firmware
13	interfaces found on PowerPC platforms.  OpenFirmware is the most commonly
14	used firmware type on general purpose PowerPC systems from Apple, IBM and
15	others.  U-Boot is typically found on embedded PowerPC hardware, but there
16	are a handful of other firmware implementations which are also popular.  Each
17	firmware interface requires a different image format.
18	
19	The boot wrapper is built from the makefile in arch/powerpc/boot/Makefile and
20	it uses the wrapper script (arch/powerpc/boot/wrapper) to generate target
21	image.  The details of the build system is discussed in the next section.
22	Currently, the following image format targets exist:
23	
24	   cuImage.%:		Backwards compatible uImage for older version of
25				U-Boot (for versions that don't understand the device
26				tree).  This image embeds a device tree blob inside
27				the image.  The boot wrapper, kernel and device tree
28				are all embedded inside the U-Boot uImage file format
29				with boot wrapper code that extracts data from the old
30				bd_info structure and loads the data into the device
31				tree before jumping into the kernel.
32				  Because of the series of #ifdefs found in the
33				bd_info structure used in the old U-Boot interfaces,
34				cuImages are platform specific.  Each specific
35				U-Boot platform has a different platform init file
36				which populates the embedded device tree with data
37				from the platform specific bd_info file.  The platform
38				specific cuImage platform init code can be found in
39				arch/powerpc/boot/cuboot.*.c.  Selection of the correct
40				cuImage init code for a specific board can be found in
41				the wrapper structure.
42	   dtbImage.%:		Similar to zImage, except device tree blob is embedded
43				inside the image instead of provided by firmware.  The
44				output image file can be either an elf file or a flat
45				binary depending on the platform.
46				  dtbImages are used on systems which do not have an
47				interface for passing a device tree directly.
48				dtbImages are similar to simpleImages except that
49				dtbImages have platform specific code for extracting
50				data from the board firmware, but simpleImages do not
51				talk to the firmware at all.
52				  PlayStation 3 support uses dtbImage.  So do Embedded
53				Planet boards using the PlanetCore firmware.  Board
54				specific initialization code is typically found in a
55				file named arch/powerpc/boot/<platform>.c; but this
56				can be overridden by the wrapper script.
57	   simpleImage.%:	Firmware independent compressed image that does not
58				depend on any particular firmware interface and embeds
59				a device tree blob.  This image is a flat binary that
60				can be loaded to any location in RAM and jumped to.
61				Firmware cannot pass any configuration data to the
62				kernel with this image type and it depends entirely on
63				the embedded device tree for all information.
64				  The simpleImage is useful for booting systems with
65				an unknown firmware interface or for booting from
66				a debugger when no firmware is present (such as on
67				the Xilinx Virtex platform).  The only assumption that
68				simpleImage makes is that RAM is correctly initialized
69				and that the MMU is either off or has RAM mapped to
70				base address 0.
71				  simpleImage also supports inserting special platform
72				specific initialization code to the start of the bootup
73				sequence.  The virtex405 platform uses this feature to
74				ensure that the cache is invalidated before caching
75				is enabled.  Platform specific initialization code is
76				added as part of the wrapper script and is keyed on
77				the image target name.  For example, all
78				simpleImage.virtex405-* targets will add the
79				virtex405-head.S initialization code (This also means
80				that the dts file for virtex405 targets should be
81				named (virtex405-<board>.dts).  Search the wrapper
82				script for 'virtex405' and see the file
83				arch/powerpc/boot/virtex405-head.S for details.
84	   treeImage.%;		Image format for used with OpenBIOS firmware found
85				on some ppc4xx hardware.  This image embeds a device
86				tree blob inside the image.
87	   uImage:		Native image format used by U-Boot.  The uImage target
88				does not add any boot code.  It just wraps a compressed
89				vmlinux in the uImage data structure.  This image
90				requires a version of U-Boot that is able to pass
91				a device tree to the kernel at boot.  If using an older
92				version of U-Boot, then you need to use a cuImage
93				instead.
94	   zImage.%:		Image format which does not embed a device tree.
95				Used by OpenFirmware and other firmware interfaces
96				which are able to supply a device tree.  This image
97				expects firmware to provide the device tree at boot.
98				Typically, if you have general purpose PowerPC
99				hardware then you want this image format.
100	
101	Image types which embed a device tree blob (simpleImage, dtbImage, treeImage,
102	and cuImage) all generate the device tree blob from a file in the
103	arch/powerpc/boot/dts/ directory.  The Makefile selects the correct device
104	tree source based on the name of the target.  Therefore, if the kernel is
105	built with 'make treeImage.walnut simpleImage.virtex405-ml403', then the
106	build system will use arch/powerpc/boot/dts/walnut.dts to build
107	treeImage.walnut and arch/powerpc/boot/dts/virtex405-ml403.dts to build
108	the simpleImage.virtex405-ml403.
109	
110	Two special targets called 'zImage' and 'zImage.initrd' also exist.  These
111	targets build all the default images as selected by the kernel configuration.
112	Default images are selected by the boot wrapper Makefile
113	(arch/powerpc/boot/Makefile) by adding targets to the $image-y variable.  Look
114	at the Makefile to see which default image targets are available.
115	
116	How it is built
117	---------------
118	arch/powerpc is designed to support multiplatform kernels, which means
119	that a single vmlinux image can be booted on many different target boards.
120	It also means that the boot wrapper must be able to wrap for many kinds of
121	images on a single build.  The design decision was made to not use any
122	conditional compilation code (#ifdef, etc) in the boot wrapper source code.
123	All of the boot wrapper pieces are buildable at any time regardless of the
124	kernel configuration.  Building all the wrapper bits on every kernel build
125	also ensures that obscure parts of the wrapper are at the very least compile
126	tested in a large variety of environments.
127	
128	The wrapper is adapted for different image types at link time by linking in
129	just the wrapper bits that are appropriate for the image type.  The 'wrapper
130	script' (found in arch/powerpc/boot/wrapper) is called by the Makefile and
131	is responsible for selecting the correct wrapper bits for the image type.
132	The arguments are well documented in the script's comment block, so they
133	are not repeated here.  However, it is worth mentioning that the script
134	uses the -p (platform) argument as the main method of deciding which wrapper
135	bits to compile in.  Look for the large 'case "$platform" in' block in the
136	middle of the script.  This is also the place where platform specific fixups
137	can be selected by changing the link order.
138	
139	In particular, care should be taken when working with cuImages.  cuImage
140	wrapper bits are very board specific and care should be taken to make sure
141	the target you are trying to build is supported by the wrapper bits.


solution & issues

"uboot requires a version of U-Boot that is able to pass a device tree to the kernel at boot" "If using an older version of U-Boot, then you need to use a cuImage instead"

1) which uboot version is able to boot new style uImage ? 2) what about the porting of the IDE support for dht-walnut to newer uBoot ? 3) what about the tftp buffer overflow bug ?


kanojio-2n-stage-kexecboot loader has been developed for ARM, but it is also fixing the dht-walnut boot issues

uboot-kanojio

kernel>=2.6.25 requires ARCH=POWERPC, but they simply do not boot with uBoot: it seems the problem is that no "old-style" uImage is available for dht-walnut/walnut in unified powerpc source; it now requires the device tree.

From Documentation/powerpc/bootwrapper.txt:

  uImage:      Native image format used by U-Boot.  The uImage target
           does not add any boot code.  It just wraps a compressed
           vmlinux in the uImage data structure.  This image
           requires a version of U-Boot that is able to pass
           a device tree to the kernel at boot.  If using an older
           version of U-Boot, then you need to use a cuImage
           instead.

There is no walnut cuImage(???), so the only choice is to use this "new-style" uImage and have uboot pass a walnut device-tree file to the kernel.

device-tree stuff is NOT supported with uboot, so ... you may use the new kanojio boot second stage loader


second stage kexec boot loader

uboot is the first stage bootloader, it's the first thing fetched by the cpu when you switch on the board.

the suggested (and hacked) uboot release is working fine, it's able to RAW read a PC partition from the hard drive putting the contents on the ram .. you could load a kernel from the HD and boot it.

it is also able to tftp a kernel from the net, but .. a bug is surviving from the 1.1.* release: this bug is limiting the amount of data you can tftp boot: 4.5Mb !

if your kernel+ramrootf is greater than 4.5Mb it will not be decompressed right cause of memory corruption (probably cause of a buffer overflow somewhere i dunno in the firmware)

so ! i developed a special second stage boot loader: it will be smaller than 4.5Mb and it will able to boot from net, pata, sata, scsi, firewire

and it should be able to read and boot all the binary format: elf, uImage, zImage, ecc


01/2010, first shot, the proof of concept

[ .k.a.n.o.j.o. ]
kexec boot loader
v01.2, 2010-01-28

press a key to stop the autoboot process

# cmdlist
 231 help
 230 cmdlist
 252 ver
 232 macaddr
 233 tcpscan
 234 ifconfig
 235 endian
 236 ttftp
 240 exec
 241 cmdline
 237 env
 237 printenv
 238 saveenv
 239 setenv
 254 
 255 reboot  
 255 exit

# help printenv
show all the environment entries

# printenv
env.machinename="dht-walnut"
env.root="/dev/hda3,ro"
env.fstype="ext3"
env.console="ttyS0,9600"
env.net_dev="eth0"
env.net_ip="192.168.1.11"
env.net_mask="255.255.255.0"
env.ttftp_server_ip="192.168.1.14"
env.ttftp_server_port="2001"
env.rmshell_port="2002"
env.timeout="5s"
env.boot="net"
env.bootfile="dht-walnut--kernel-2.6.22-ramrootfs.img"
env.net="ttftp $ttfpt_server_ip $ttftp_server_port $bootfile autoexec"

# ttftp
connect(): Connection refused, no ttftp server found

# tcpscan $ttftp_server 1 2100
TCP port scanning
connect_port={ 22  23  80  111  443 2000}

# setenv ttftp_server_port 2000

# boot
method=net
downloading "dht-walnut--kernel-2.6.22-ramrootfs.img" from 192.168.1.14/2000 ... done
kexec ... kernel loaded into ram ... jumping to it

i will release as soon as possible