From e4680bbaab69e5bd9f6b022d5ae938259bfc6a24 Mon Sep 17 00:00:00 2001 From: Francis Rowe Date: Sat, 4 Apr 2015 19:05:59 +0100 Subject: docs/install/*_external.html: Update notes: switchable graphics --- docs/install/t400_external.html | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'docs/install/t400_external.html') diff --git a/docs/install/t400_external.html b/docs/install/t400_external.html index 207e51a3..e5208419 100644 --- a/docs/install/t400_external.html +++ b/docs/install/t400_external.html @@ -54,16 +54,23 @@

A note about GPUs

- This guide currently assumes that you have an Intel GPU (non-switchable). - Some T400 have switchable graphics (ATI), which means that you can choose between ATI or Intel - in the BIOS setup. When switching to Intel, is lenovobios not enabling ATI - (where ATI is disabled by default and the system uses the Intel chip), or are they - disabling it (where the system uses the ATI chip by default)? + Some models have an Intel GPU, while others have both an ATI and an Intel GPU; this + is referred to as "switchable graphics". In the BIOS setup programme + for lenovobios, you can specify that the system will use one or the other (but not both).

- Basically, switchable graphics is untested, but it should be easy to get it working - (if it doesn't already work). + Libreboot is known to work on systems with only the Intel GPU, using native graphics initialization. + On systems with switchable graphics, it is believed that the ATI chip is used by default; coreboot + was tested with the native init and it didn't work, so the theory is that you have to disable + the ATI chip and make it use the Intel GPU instead (with native graphics), using the same method + as lenovobios. The other alternative is to implement native graphics initialization for the ATI chip + used on some models, but this is much harder (disabling the ATI chip in favour of Intel is likely much easier). +

+ +

+ For now (unless you want to help make systems with switchable graphics work, where a display + is initialized for the Intel GPU), you should avoid systems with switchable graphics.

CPU paste required

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