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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-04-19 16:17:34 (GMT) |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-04-19 16:17:34 (GMT) |
commit | cf816ecb533ab96b883dfdc0db174598b5b5c4d2 (patch) | |
tree | 1b7705db288ae2917105e624b01fdf81e0882bf1 /Documentation/debugging-via-ohci1394.txt | |
parent | adf6d34e460387ee3e8f1e1875d52bff51212c7d (diff) | |
parent | 15f7d677ccff6f0f5de8a1ee43a792567e9f9de9 (diff) | |
download | linux-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.txt | 16 |
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 ----- |