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1Summary
2=======
3The README is for the boot procedure on the ipam390 board
4
5In the context of U-Boot, the board is booted in three stages. The initial
6bootloader which executes upon reset is the ROM Boot Loader (RBL) and sits
7in the internal ROM. The RBL initializes the internal memory and then
8depending on the exact board and pin configurations will initialize another
9controller (such as NAND) to continue the boot process by loading
10the secondary program loader (SPL). The SPL will initialize the system
11further (some clocks, SDRAM). As on this board is used the falcon boot
12mode, now 2 ways are possible depending on the GPIO 7_14 input pin,
13connected with the "soft reset switch"
14
15If this pin is logical 1 (high level):
16spl code starts the kernel image without delay
17
18If this pin is logical 0 (low level):
19spl code starts the u-boot image
20
21AIS is an image format defined by TI for the images that are to be loaded
22to memory by the RBL. The image is divided into a series of sections and
23the image's entry point is specified. Each section comes with meta data
24like the target address the section is to be copied to and the size of the
25section, which is used by the RBL to load the image. At the end of the
26image the RBL jumps to the image entry point.  The AIS format allows for
27other things such as programming the clocks and SDRAM if the header is
28programmed for it.  We do not take advantage of this and instead use SPL as
29it allows for additional flexibility (run-time detect of board revision,
30loading the next image from a different media, etc).
31
32Compilation
33===========
34run "tools/buildman/buildman -k ipam390" in the u-boot source tree.
35Once this build completes you will have a ../current/ipam390/u-boot.ais file
36that needs to be written to the nand flash.
37
38Flashing the images to NAND
39==========================
40The AIS image can be written to NAND flash using the following commands.
41Assuming that the network is configured and enabled and the u-boot.ais file
42is tftp'able.
43
44U-Boot > print upd_uboot
45upd_uboot=tftp c0000000 ${u-boot};nand erase.part u-boot;nand write c0000000 20000 ${filesize}
46U-Boot >
47U-Boot > run upd_uboot
48Using DaVinci-EMAC device
49TFTP from server 192.168.1.1; our IP address is 192.168.20.71
50Filename '/tftpboot/ipam390/u-boot.ais'.
51Load address: 0xc0000000
52Loading: ##################################
53	 1.5 MiB/s
54done
55Bytes transferred = 493716 (78894 hex)
56
57NAND erase.part: device 0 offset 0x20000, size 0x160000
58Erasing at 0x160000 -- 100% complete.
59OK
60
61NAND write: device 0 offset 0x20000, size 0x78894
62 493716 bytes written: OK
63U-Boot >
64
65Recovery
66========
67
68In the case of a "bricked" board, you need to use the TI tools found
69here[1] to create an uboot-uart-ais.bin file
70
71- cd to the u-boot source tree
72
73- compile the u-boot for the ipam390 board:
74$ tools/buildman/buildman -k ipam390
75
76  -> Now we shall have u-boot.bin
77
78- Create u-boot-uart-ais.bin
79$ mono HexAIS_OMAP-L138.exe -entrypoint 0xC1080000 -ini ipam390-ais-uart.cfg \
80	-o ../current/ipam390/uboot-uart-ais.bin ./u-boot.bin@0xC1080000;
81
82Note: The ipam390-ais-uart.cfg is found in the board directory
83for the ipam390 board, u-boot:/board/Barix/ipam390/ipam390-ais-uart.cfg
84
85- We can now run bootloader on IPAM390 via UART using the command below:
86
87$ mono ./slh_OMAP-L138.exe -waitForDevice -v -p /dev/tty.UC-232AC uboot-uart-ais.bin
88NOTE: Do not cancel the command execution! The command takes 20+ seconds
89to upload u-boot over serial and run it!
90Outcome:
91Waiting for the OMAP-L138...
92(AIS Parse): Read magic word 0x41504954.
93(AIS Parse): Waiting for BOOTME... (power on or reset target now)
94(AIS Parse): BOOTME received!
95(AIS Parse): Performing Start-Word Sync...
96(AIS Parse): Performing Ping Opcode Sync...
97(AIS Parse): Processing command 0: 0x5853590D.
98(AIS Parse): Performing Opcode Sync...
99(AIS Parse): Executing function...
100(AIS Parse): Processing command 1: 0x5853590D.
101(AIS Parse): Performing Opcode Sync...
102(AIS Parse): Executing function...
103(AIS Parse): Processing command 2: 0x5853590D.
104(AIS Parse): Performing Opcode Sync...
105(AIS Parse): Executing function...
106(AIS Parse): Processing command 3: 0x5853590D.
107(AIS Parse): Performing Opcode Sync...
108(AIS Parse): Executing function...
109(AIS Parse): Processing command 4: 0x5853590D.
110(AIS Parse): Performing Opcode Sync...
111(AIS Parse): Executing function...
112(AIS Parse): Processing command 5: 0x58535901.
113(AIS Parse): Performing Opcode Sync...
114(AIS Parse): Loading section...
115(AIS Parse): Loaded 326516-Byte section to address 0xC1080000.
116(AIS Parse): Processing command 6: 0x58535906.
117(AIS Parse): Performing Opcode Sync...
118(AIS Parse): Performing jump and close...
119(AIS Parse): AIS complete. Jump to address 0xC1080000.
120(AIS Parse): Waiting for DONE...
121(AIS Parse): Boot completed successfully.
122
123Operation completed successfully.
124
125Falcon Bootmode (boot linux without booting U-Boot)
126===================================================
127
128The Falcon Mode extends this way allowing to start the Linux kernel directly
129from SPL. A new command is added to U-Boot to prepare the parameters that SPL
130must pass to the kernel, using ATAGS or Device Tree.
131
132In normal mode, these parameters are generated each time before
133loading the kernel, passing to Linux the address in memory where
134the parameters can be read.
135With Falcon Mode, this snapshot can be saved into persistent storage and SPL is
136informed to load it before running the kernel.
137
138To boot the kernel, these steps under a Falcon-aware U-Boot are required:
139
1401. Boot the board into U-Boot.
141Use the "spl export" command to generate the kernel parameters area or the DT.
142U-Boot runs as when it boots the kernel, but stops before passing the control
143to the kernel.
144
145Here the command sequence for the ipam390 board:
146- load the linux kernel image into ram:
147
148U-Boot > nand read c0100000 2 200000 400000
149
150NAND read: device 0 offset 0x200000, size 0x400000
151 4194304 bytes read: OK
152
153- generate the bootparms image:
154
155U-Boot > spl export atags c0100000
156## Booting kernel from Legacy Image at c0100000 ...
157   Image Name:   Linux-3.5.1
158   Image Type:   ARM Linux Kernel Image (uncompressed)
159   Data Size:    2504280 Bytes = 2.4 MiB
160   Load Address: c0008000
161   Entry Point:  c0008000
162   Verifying Checksum ... OK
163   Loading Kernel Image ... OK
164subcommand not supported
165subcommand not supported
166Argument image is now in RAM at: 0xc0000100
167
168- copy the bootparms image into nand:
169
170U-Boot > mtdparts
171
172device nand0 <davinci_nand.0>, # parts = 6
173 #: name		size		offset		mask_flags
174 0: u-boot-env          0x00020000	0x00000000	0
175 1: u-boot              0x00160000	0x00020000	0
176 2: bootparms           0x00020000	0x00180000	0
177 3: factory-info        0x00060000	0x001a0000	0
178 4: kernel              0x00400000	0x00200000	0
179 5: rootfs              0x07a00000	0x00600000	0
180
181active partition: nand0,0 - (u-boot-env) 0x00020000 @ 0x00000000
182
183defaults:
184mtdids  : nand0=davinci_nand.0
185mtdparts: mtdparts=davinci_nand.0:128k(u-boot-env),1408k(u-boot),128k(bootparms),384k(factory-info),4M(kernel),-(rootfs)
186U-Boot > nand erase.part bootparms
187
188NAND erase.part: device 0 offset 0x180000, size 0x20000
189Erasing at 0x180000 -- 100% complete.
190OK
191U-Boot > nand write c0000100 180000 20000
192
193NAND write: device 0 offset 0x180000, size 0x20000
194 131072 bytes written: OK
195U-Boot >
196
197You can use also the predefined U-Boot Environment variable "setbootparms",
198which will do all the above steps in one command:
199
200U-Boot > print setbootparms
201setbootparms=nand read c0100000 200000 400000;spl export atags c0100000;nand erase.part bootparms;nand write c0000100 180000 20000
202U-Boot > run setbootparms
203
204NAND read: device 0 offset 0x200000, size 0x400000
205 4194304 bytes read: OK
206## Booting kernel from Legacy Image at c0100000 ...
207   Image Name:   Linux-3.5.1
208   Image Type:   ARM Linux Kernel Image (uncompressed)
209   Data Size:    2504280 Bytes = 2.4 MiB
210   Load Address: c0008000
211   Entry Point:  c0008000
212   Verifying Checksum ... OK
213   Loading Kernel Image ... OK
214subcommand not supported
215subcommand not supported
216Argument image is now in RAM at: 0xc0000100
217
218NAND erase.part: device 0 offset 0x180000, size 0x20000
219Erasing at 0x180000 -- 100% complete.
220OK
221
222NAND write: device 0 offset 0x180000, size 0x20000
223 131072 bytes written: OK
224U-Boot >
225
226Links
227=====
228[1]
229 http://sourceforge.net/projects/dvflashutils/files/OMAP-L138/
230