TouchBook, use files from SD card
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Wouter Rademaker (458) 197 posts |
Support is added for the TouchBook’s SD slot, but how do I get it to change the filesystem to SDFS? I have tried putting a saved CMOS file in the boot partition, but that doesn’t changed anything. What else can I try? |
andym (447) 464 posts |
I’m sure I used to have some software that loaded CMOS settings as part of the Boot sequence. It was a dedicated app that I used to use on the Touchbook, that loaded from either Chioces.PreDesk or Choices.Tasks, I think. Trouble is, I can’t find it, or remember it’s name. Maybe someone else knows? |
Wouter Rademaker (458) 197 posts |
Loading the CMOS settings as part of the Boot sequence would be to late, because I want to change the disc with the Boot sequence. SDFS::0.$.CMOS gets written to, when you change something in the configuration. But, so far as I can tell, it is not read when booting. |
Jeffrey Lee (213) 6046 posts |
Yeah, that’s one of the reasons why I hadn’t bothered to add SD card support before now. With other machines, we can use boot.scr/uenv.txt to get u-boot to load the CMOS file on startup. But it looks like the version of u-boot used by the Touch Book has been configured to ignore those files and just go straight to loading a kernel image. I’ll need to spend some time taking a closer look at how things are set up to see if there are any alternative ways we can do things. |
Wouter Rademaker (458) 197 posts |
I have found on http://tb.mrkva.eu/boot/ a standard U-boot patched for the Touch Book. It boots Linux and RISC OS uImages. This uEnv.txt works:
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Wouter Rademaker (458) 197 posts |
And this script run under Linux builds a, with the official version of the U-boat used by the Touch Book, working boot.scr: but change to
The dual boot option is still usable. (edit on 2018-01-28)
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Steve Pampling (1551) 7951 posts |
Correct me if I’m wrong, but I thought the boot sequence for these various boards was: Now given this the question is do we need anything from the current u-boot that couldn’t be done by an alternate code object, which would have to be called MLO1, that purely loaded the RISCOS image? NB. Most of the boot time on many of these systems is in that MLO => U-Boot=> OSimage sequence2 1 MLO is the target name for the OMAP boot code so calling it anything else breaks things. |
Jeffrey Lee (213) 6046 posts |
There’ll be some stuff which u-boot does which RISC OS relies on, e.g. setting up pin mux settings or enabling certain bits of hardware. Some of this will be complicated by the fact that there are usually several different hardware revisions that any particular u-boot version needs to deal with. Plus of course there are board-specific versions of the MLO, since they need to know the correct RAM timings to use. But basically, yeah, there’s nothing stopping us from replacing MLO + u-boot with our own solution, except for the time required to get it working and the time required to maintain it going forward. And the solution might not work (conveniently) for some systems if the default boot settings mean that the system doesn’t load our MLO by default (e.g. non-xM beagleboards default to loading the MLO from NAND, as would most consumer devices like the Pandora and TouchBook, I think) |
Wouter Rademaker (458) 197 posts |
The most important job of MLO is to set up the memory so the larger, full bootloader can be loaded. Chances are that a bootloader with the features needed to load RISC OS is larger than the maximum size for a MLO. Then you still need a two-stage bootloader. So you might as well use the standard MLO and u-boat. Much of the boot time are the various timeouts. |
Steve Pampling (1551) 7951 posts |
1MB IIRC. I think Jeffreys comments about the maintained-by-someone-else code probably cover the biggest argument against a custom loader |
Jeffrey Lee (213) 6046 posts |
I thought maximum MLO size was 64K (or 32K?) since the MLO gets loaded into a small amount of SRAM that’s built into the chip. Then the MLO initialises the main DRAM and loads u-boot or a kernel image, depending on how the MLO has been configured. It has to happen that way because there’s no standard way for the SoC to know how to configure the DRAM. |
Raik (463) 2029 posts |
The “u-boot-patch” and the “boot.scr change” are noot working with my TouchBook. Other revision? I have try to use the cmos widget. It looks like, it works. I have also replaced the tablet accu. Next step, RTC fix. Something like this but with a RPi working RTC. |
Raik (463) 2029 posts |
With a SystemDisc it works very fine. No USBStick needed. RPi RTC is installed now… In Linux I can detect the RTC but in RISC OS it not works. So I’m at the end because too stupid to change the driver / ROM. |
Chris Evans (457) 1614 posts |
I suspect the RTC problem will be the I2C bus number? Is there more than one accessible on the TouchBook? I see the TouchBook uses an MLO! What does it stand for? |
Rick Murray (539) 13422 posts |
I can’t find any explanation of the acronym. It’s just what the OMAP bootloader calls the x-loader (second stage boot) program. Maybe it’s the initials of the designer or something? Like the Nick and Hugo in the ADFS maps. |
David Pitt (102) 743 posts | |
Raik (463) 2029 posts |
Jeffrey has send a new uImage (ROM) to try. Now the RTC works… |
Erich Kraehenbuehl (1634) 176 posts |
Is there a source, where i can get an sd-card image for the touchbook? Does some kind soul know, where i could get such? |
Raik (463) 2029 posts |
There is not an sd-card image aviable. I can made one but is not necessary. |
Erich Kraehenbuehl (1634) 176 posts |
@Raik: thank you. The link helped me a lot. could find the reason for my TB not starting up: death Li-battery. now i have to wait for a new one.. |
Erich Kraehenbuehl (1634) 176 posts |
@ Raik: what happens if one try to start th TB, with the li-battery (in the upper part) disconnected? does it start up or not? ( only the powersupply (5v) connected to the upper part ( tablet + screen.)) here it doesnt start ( red led lights for less as one second). i need just to know, if its only the defect battery, or if theres another problem too. |
Jeffrey Lee (213) 6046 posts |
I might be wrong but I don’t think it will start if the battery is disconnected. One thing you can try doing is taking apart the keyboard and connecting the keyboard battery to the main board instead of the tablet battery. Taking the keyboard apart is also a good way of charging the tablet battery if you’re having trouble charging it normally (connect the tablet battery to the charging circuit in the keyboard) http://alwaysinnovating.com/wiki/index.php/Tablet_battery_charging_fix#Alternative_way |
Raik (463) 2029 posts |
Note: I have try the hardware fix on top of Jeffreys link. With this, my touchbook no longer boot. I have remove the fix… I can confirm. Without a tablet battery, it works, with a defect tablet battery not. |
Erich Kraehenbuehl (1634) 176 posts |
@Raik: thank you. That proves, that there has to be a problem on my mainboard. |
Raik (463) 2029 posts |
I will look at at the evening but I remember no “living sign” without a working boot card. Only a power LED. At first I use a SDCreated card only with the bootfiles. SDCreate / MKImage create a uImage from the RISC OS ROM. This is what you need. |
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