1 The Intel Assabet (SA-1110 evaluation) board
2 ============================================
5 http://developer.intel.com/design/strong/quicklist/eval-plat/sa-1110.htm
6 http://developer.intel.com/design/strong/guides/278278.htm
8 Also some notes from John G Dorsey <jd5q@andrew.cmu.edu>:
9 http://www.cs.cmu.edu/~wearable/software/assabet.html
15 To build the kernel with current defaults:
22 The resulting kernel image should be available in linux/arch/arm/boot/zImage.
25 Installing a bootloader
26 -----------------------
28 A couple of bootloaders able to boot Linux on Assabet are available:
30 BLOB (http://www.lart.tudelft.nl/lartware/blob/)
32 BLOB is a bootloader used within the LART project. Some contributed
33 patches were merged into BLOB to add support for Assabet.
35 Compaq's Bootldr + John Dorsey's patch for Assabet support
36 (http://www.handhelds.org/Compaq/bootldr.html)
37 (http://www.wearablegroup.org/software/bootldr/)
39 Bootldr is the bootloader developed by Compaq for the iPAQ Pocket PC.
40 John Dorsey has produced add-on patches to add support for Assabet and
43 RedBoot (http://sources.redhat.com/redboot/)
45 RedBoot is a bootloader developed by Red Hat based on the eCos RTOS
46 hardware abstraction layer. It supports Assabet amongst many other
49 RedBoot is currently the recommended choice since it's the only one to have
50 networking support, and is the most actively maintained.
52 Brief examples on how to boot Linux with RedBoot are shown below. But first
53 you need to have RedBoot installed in your flash memory. A known to work
54 precompiled RedBoot binary is available from the following location:
56 ftp://ftp.netwinder.org/users/n/nico/
57 ftp://ftp.arm.linux.org.uk/pub/linux/arm/people/nico/
58 ftp://ftp.handhelds.org/pub/linux/arm/sa-1100-patches/
60 Look for redboot-assabet*.tgz. Some installation infos are provided in
64 Initial RedBoot configuration
65 -----------------------------
67 The commands used here are explained in The RedBoot User's Guide available
68 on-line at http://sources.redhat.com/ecos/docs-latest/redboot/redboot.html.
69 Please refer to it for explanations.
71 If you have a CF network card (my Assabet kit contained a CF+ LP-E from
72 Socket Communications Inc.), you should strongly consider using it for TFTP
73 file transfers. You must insert it before RedBoot runs since it can't detect
76 To initialize the flash directory:
80 To initialize the non-volatile settings, like whether you want to use BOOTP or
81 a static IP address, etc, use this command:
86 Writing a kernel image into flash
87 ---------------------------------
89 First, the kernel image must be loaded into RAM. If you have the zImage file
90 available on a TFTP server:
92 load zImage -r -b 0x100000
94 If you rather want to use Y-Modem upload over the serial port:
96 load -m ymodem -r -b 0x100000
100 fis create "Linux kernel" -b 0x100000 -l 0xc0000
106 The kernel still requires a filesystem to boot. A ramdisk image can be loaded
109 load ramdisk_image.gz -r -b 0x800000
111 Again, Y-Modem upload can be used instead of TFTP by replacing the file name
114 Now the kernel can be retrieved from flash like this:
116 fis load "Linux kernel"
118 or loaded as described previously. To boot the kernel:
120 exec -b 0x100000 -l 0xc0000
122 The ramdisk image could be stored into flash as well, but there are better
123 solutions for on-flash filesystems as mentioned below.
129 Using JFFS2 (the Second Journalling Flash File System) is probably the most
130 convenient way to store a writable filesystem into flash. JFFS2 is used in
131 conjunction with the MTD layer which is responsible for low-level flash
132 management. More information on the Linux MTD can be found on-line at:
133 http://www.linux-mtd.infradead.org/. A JFFS howto with some infos about
134 creating JFFS/JFFS2 images is available from the same site.
136 For instance, a sample JFFS2 image can be retrieved from the same FTP sites
137 mentioned below for the precompiled RedBoot image.
141 load sample_img.jffs2 -r -b 0x100000
143 The result should look like:
145 RedBoot> load sample_img.jffs2 -r -b 0x100000
146 Raw file loaded 0x00100000-0x00377424
148 Now we must know the size of the unallocated flash:
155 0x500E0000 .. 0x503C0000
157 The values above may be different depending on the size of the filesystem and
158 the type of flash. See their usage below as an example and take care of
159 substituting yours appropriately.
161 We must determine some values:
163 size of unallocated flash: 0x503c0000 - 0x500e0000 = 0x2e0000
164 size of the filesystem image: 0x00377424 - 0x00100000 = 0x277424
166 We want to fit the filesystem image of course, but we also want to give it all
167 the remaining flash space as well. To write it:
169 fis unlock -f 0x500E0000 -l 0x2e0000
170 fis erase -f 0x500E0000 -l 0x2e0000
171 fis write -b 0x100000 -l 0x277424 -f 0x500E0000
172 fis create "JFFS2" -n -f 0x500E0000 -l 0x2e0000
174 Now the filesystem is associated to a MTD "partition" once Linux has discovered
175 what they are in the boot process. From Redboot, the 'fis list' command
179 Name FLASH addr Mem addr Length Entry point
180 RedBoot 0x50000000 0x50000000 0x00020000 0x00000000
181 RedBoot config 0x503C0000 0x503C0000 0x00020000 0x00000000
182 FIS directory 0x503E0000 0x503E0000 0x00020000 0x00000000
183 Linux kernel 0x50020000 0x00100000 0x000C0000 0x00000000
184 JFFS2 0x500E0000 0x500E0000 0x002E0000 0x00000000
186 However Linux should display something like:
188 SA1100 flash: probing 32-bit flash bus
189 SA1100 flash: Found 2 x16 devices at 0x0 in 32-bit mode
190 Using RedBoot partition definition
191 Creating 5 MTD partitions on "SA1100 flash":
192 0x00000000-0x00020000 : "RedBoot"
193 0x00020000-0x000e0000 : "Linux kernel"
194 0x000e0000-0x003c0000 : "JFFS2"
195 0x003c0000-0x003e0000 : "RedBoot config"
196 0x003e0000-0x00400000 : "FIS directory"
198 What's important here is the position of the partition we are interested in,
199 which is the third one. Within Linux, this correspond to /dev/mtdblock2.
200 Therefore to boot Linux with the kernel and its root filesystem in flash, we
201 need this RedBoot command:
203 fis load "Linux kernel"
204 exec -b 0x100000 -l 0xc0000 -c "root=/dev/mtdblock2"
206 Of course other filesystems than JFFS might be used, like cramfs for example.
207 You might want to boot with a root filesystem over NFS, etc. It is also
208 possible, and sometimes more convenient, to flash a filesystem directly from
209 within Linux while booted from a ramdisk or NFS. The Linux MTD repository has
210 many tools to deal with flash memory as well, to erase it for example. JFFS2
211 can then be mounted directly on a freshly erased partition and files can be
212 copied over directly. Etc...
218 All the commands above aren't so useful if they have to be typed in every
219 time the Assabet is rebooted. Therefore it's possible to automatize the boot
220 process using RedBoot's scripting capability.
222 For example, I use this to boot Linux with both the kernel and the ramdisk
223 images retrieved from a TFTP server on the network:
226 Run script at boot: false true
228 Enter script, terminate with empty line
229 >> load zImage -r -b 0x100000
230 >> load ramdisk_ks.gz -r -b 0x800000
231 >> exec -b 0x100000 -l 0xc0000
233 Boot script timeout (1000ms resolution): 3
234 Use BOOTP for network configuration: true
235 GDB connection port: 9000
236 Network debug at boot time: false
237 Update RedBoot non-volatile configuration - are you sure (y/n)? y
239 Then, rebooting the Assabet is just a matter of waiting for the login prompt.
248 Status of peripherals in -rmk tree (updated 14/10/2001)
249 -------------------------------------------------------
253 Radio: TX, RX, CTS, DSR, DCD, RI
255 COM: TX, RX, CTS, DSR, DCD, RTS, DTR, PM
257 I2C: Implemented, not fully tested.
258 L3: Fully tested, pass.
262 LCD: Fully tested. PM
263 (LCD doesn't like being blanked with
269 Playback: Fully tested, pass.
270 Record: Implemented, not tested.
274 Audio play: Implemented, not heavily tested.
275 Audio rec: Implemented, not heavily tested.
276 Telco audio play: Implemented, not heavily tested.
277 Telco audio rec: Implemented, not heavily tested.
284 LPE: Fully tested, pass.
287 SIR: Fully tested, pass.
288 FIR: Fully tested, pass.
293 COM1,2: TX, RX, CTS, DSR, DCD, RTS, DTR
295 USB: Implemented, not heavily tested.
296 PCMCIA: Implemented, not heavily tested.
298 CF: Implemented, not heavily tested.
301 More stuff can be found in the -np (Nicolas Pitre's) tree.