Yes and no. How's that for an answer! First, let me tell you that it is entirely possible to do what I think it is you want to do. My Palm experience includes principal hardware engineer for the PalmIII, and engineering team member for the PalmVII, Tungsten-W, Tungsten-T, and I've written several alternative OS's for palm devices. It can work just fine. You need to know a lot about the device, though.
Direct and complete hardware access is only slightly more difficult on any of the ARM platforms, but both ARM and 68K platforms are essentially open to the world, or can be made so. For example, you have full access at all times on any of the 68K devices. The only area that may cause you trouble will be the things your OS must do to either make the hardware function as designed, or keep the hardware from interfering with whatever you may desire it to do. The Palm devices are not designed as generic microprocessor platforms, but are highly integrated systems. Certainly, you can disable system features to the point that you have simply a processor and memory, but to be useful, you would need to re-enable features such as serial and USB ports, IrDA, battery management, LCD, backlight, touch screen, buttons, wireless subsystems, audio subsystems, and the like. You would be limited to doing this in accordance with the way the device was designed, or it may not function. To make a long story short, you would need a system description and schematics to the extent that you could determine how, where and why the components are connected, and you would need to understand how the PDA was designed to function as an integrated system. After that, it's a piece of cake :) Jeff PS. Someone suggested writing your OS on top of PalmOS, or you can write it on top of the existing HAL/DAL. This is often done if it is a proof of concept, something like a school project, or a value-added/embedded use for the device. -------------------- Jeff Loucks Work 425-284-1128 [EMAIL PROTECTED] Home 253-851-8908 [EMAIL PROTECTED] Mobile 253-691-8812 -----Original Message----- From: Leo [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 23, 2005 3:59 PM To: Palm Developer Forum Subject: RE: change os of palm We wrote a HAL for a microcontroller, but in that case we knew that we could program it as we wish. In the case of the palm we want to know if we can do the same, i mean use the complete instruction set and interact directly with the microprocessor. Of course we have to build a bootloader, drivers and a lot of things that together make the HAL. What we want to know is if there is any limitation concerning access to the chip a very low level. Thank you, Leo --- Jeffry Loucks <[EMAIL PROTECTED]> wrote: > > Leo, > > Have you ever written a hardware layer for an > embedded microprocessor > system? If so, then you probably had access to the > specifications, including > schematics and sample drivers. Do you have these > specifications for any of > the Palm-ish devices you wish your OS to be > compatible? > > If you are satisfied that you understand the > hardware, then are you asking > how to load, execute and test your new OS? If you > presume to understand how > to write the OS for a platform, then I would assume > you'd know how to load > and test it. > > What is it you want to know? What are your > limitations? Be specific, please. > > > -------------------- > Jeff Loucks > Work 425-284-1128 [EMAIL PROTECTED] > Home 253-851-8908 [EMAIL PROTECTED] > Mobile 253-691-8812 > > > -----Original Message----- > From: Leo [mailto:[EMAIL PROTECTED] > Sent: Tuesday, March 22, 2005 8:51 AM > To: Palm Developer Forum > Subject: Re: change os of palm > > > But can't we use the palm to program its > microprocessor. What are the limitations? Be > specific, > please. > Thank you, > -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
