From 080de8c2c57e3199eee837fe8b6d35a43679f8c1 Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Thu, 28 Feb 2008 20:54:43 +0100 Subject: firewire: fw-ohci: add option for remote debugging This way firewire-ohci can be used for remote debugging like ohci1394. Version with amendment from Fri, 11 Apr 2008 00:08:08 +0200. Signed-off-by: Stefan Richter Acked-by: Bernhard Kaindl --- Documentation/debugging-via-ohci1394.txt | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'Documentation/debugging-via-ohci1394.txt') diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt index c360d4e91b4..59a91e5c690 100644 --- a/Documentation/debugging-via-ohci1394.txt +++ b/Documentation/debugging-via-ohci1394.txt @@ -41,15 +41,19 @@ to a working state and enables physical DMA by default for all remote nodes. This can be turned off by ohci1394's module parameter phys_dma=0. The alternative firewire-ohci driver in drivers/firewire uses filtered physical -DMA, hence is not yet suitable for remote debugging. +DMA by default, which is more secure but not suitable for remote debugging. +Compile the driver with CONFIG_FIREWIRE_OHCI_REMOTE_DMA (Kernel hacking menu: +Remote debugging over FireWire with firewire-ohci) to get unfiltered physical +DMA. -Because ohci1394 depends on the PCI enumeration to be completed, an -initialization routine which runs pretty early (long before console_init() -which makes the printk buffer appear on the console can be called) was written. +Because ohci1394 and firewire-ohci depend on the PCI enumeration to be +completed, an initialization routine which runs pretty early has been +implemented for x86. This routine runs long before console_init() can be +called, i.e. before the printk buffer appears on the console. To activate it, enable CONFIG_PROVIDE_OHCI1394_DMA_INIT (Kernel hacking menu: -Provide code for enabling DMA over FireWire early on boot) and pass the -parameter "ohci1394_dma=early" to the recompiled kernel on boot. +Remote debugging over FireWire early on boot) and pass the parameter +"ohci1394_dma=early" to the recompiled kernel on boot. Tools ----- -- cgit v1.2.3