On 12/12/07 09:40 +0900, Jun Koi wrote:
On 12/10/07, Uwe Hermann uwe@hermann-uwe.de wrote:
On Wed, Dec 05, 2007 at 12:31:54PM -0800, Wakefield, John wrote:
I have an Acer 5102WLMi Notebook with Dual Core AMD TL50s, which are 64
I'm afraid LinuxBIOS doesn't yet work on laptops, those are much harder to support than "normal" PCs for various reasons. It's on our TODO list to support laptops too sooner or later, but it's not a trivial task.
Uwe, could you elaborate a bit here? Why supporting laptops is technically much harder than desktop??
There are a number of reasons why laptops are considerably more complex:
1) The embedded controller. As Gregg alluded to, embedded 8051 microcontrollers manage a huge chunk of the laptop, from interfacing to the LPC, inputs and outputs, and even power control. No BIOS implementation for a laptop can avoid interfacing with the embedded controller. The problem is that embedded controllers are notorious black box devices. They are most often specific to individual platform designs, and deeply proprietary. Without in depth knowledge of the specific embedded controller at hand, getting it to work is a very long shot. If you want some idea of how tightly coupled the EC is to the BIOS, take a look at the OLPC implementation - you will see the OFW and the kernel littered with embedded controller references, and bear in mind that during that project, the OLPC team had unprecedented visibility into the EC code. They _are_ that evil.
2) Laptops have different design constraints then desktops - this might seem like a nobrainer, but it does affect us negatively. With small form factors, ROMs are usually soldered down (sockets take up too much room). Legacy devices such as serial ports are omitted, as are JTAG connectors and LPC headers and other things that we could use in a pinch to get access to the machine. Laptops will normally use different revisions of silicon to save money, power or real estate, and usually what gets left on the floor are the tools we can use to get at the system core. Most of the devices are soldered down, and there are no PCI or PCIe busses that we can tie into. Unlike PCI cards, mobile GPUS and NICs won't have a companion EEPROM to store optionROM data; instead that will be carried on the ROM, which makes it that much more difficult to replace the firmware image with LinuxBIOS. And last but not least, it is rather difficult to take a laptop apart to get at the motherboard, yet still keep everything working.
In short, the downside is huge, the upside is minimal, and few people are willing to donate their laptops to potential bricking.
Jordan