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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2008-04-19 16:17:34 (GMT)
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-04-19 16:17:34 (GMT)
commitcf816ecb533ab96b883dfdc0db174598b5b5c4d2 (patch)
tree1b7705db288ae2917105e624b01fdf81e0882bf1 /Documentation/debugging-via-ohci1394.txt
parentadf6d34e460387ee3e8f1e1875d52bff51212c7d (diff)
parent15f7d677ccff6f0f5de8a1ee43a792567e9f9de9 (diff)
downloadlinux-fsl-qoriq-cf816ecb533ab96b883dfdc0db174598b5b5c4d2.tar.xz
Merge branch 'merge-fixes' into devel
Diffstat (limited to 'Documentation/debugging-via-ohci1394.txt')
-rw-r--r--Documentation/debugging-via-ohci1394.txt16
1 files changed, 10 insertions, 6 deletions
diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt
index c360d4e..59a91e5 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
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