Date: Sun, 31 Jul 2016 19:21:13 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-arm@FreeBSD.org Subject: [Bug 211484] Zynq/Zybo cannot mount USB drives as root Message-ID: <bug-211484-7@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=211484 Bug ID: 211484 Summary: Zynq/Zybo cannot mount USB drives as root Product: Base System Version: CURRENT Hardware: arm OS: Any Status: New Severity: Affects Only Me Priority: --- Component: arm Assignee: freebsd-arm@FreeBSD.org Reporter: thoma555-bsd@yahoo.com Created attachment 173141 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=173141&action=edit patch to zynq-7000.dtsi A Zynq/Zybo system cannot mount a USB drive/stick as the root filesystem. The problem is the the ehci driver tries to DMA to a location in the first half megabyte of memory space which has several caveats on Zynq including a hole between 256K-512K that is inaccessible by bus masters. Originally, I tried to avoid something like this happening by starting memory at 0x100000 in the Zynq DTS file. But, ubldr "fixes up" memory ranges using information from u-boot (retrieved by a sysinfo call to the API). That causes the kernel to allocate the first megabyte. The simplest work-around seems to be to add a “memreserve” property to the DTS. Also, It turns out that only the first half megabyte needs to be excluded. -- You are receiving this mail because: You are the assignee for the bug.
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