Bug 194952
| Summary: | uart(4) needs BayTrail support for Minnowboard Max | ||||||
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| Product: | Base System | Reporter: | Ed Maste <emaste> | ||||
| Component: | kern | Assignee: | Marcel Moolenaar <marcel> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Some People | CC: | k, marcel, marcnarc | ||||
| Priority: | --- | ||||||
| Version: | CURRENT | ||||||
| Hardware: | Any | ||||||
| OS: | Any | ||||||
| See Also: | https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=192324 | ||||||
| Attachments: |
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Created attachment 159741 [details]
Proposed fix for BayTril as low-level console
FreeBSD-current (at time of this writing) already supports the H/W, but not yet when used as low-level console. This patch fixes that.
A commit references this bug: Author: marcel Date: Wed Aug 12 15:26:35 UTC 2015 New revision: 286667 URL: https://svnweb.freebsd.org/changeset/base/286667 Log: Better support memory mapped console devices, such as VGA and EFI frame buffers and memory mapped UARTs. 1. Delay calling cninit() until after pmap_bootstrap(). This makes sure we have PMAP initialized enough to add translations. Keep kdb_init() after cninit() so that we have console when we need to break into the debugger on boot. 2. Unfortunately, the ATPIC code had be moved as well so as to avoid a spurious trap #30. The reason for which is not known at this time. 3. In pmap_mapdev_attr(), when we need to map a device prior to the VM system being initialized, use virtual_avail as the KVA to map the device at. In particular, avoid using the direct map on amd64 because we can't demote by virtue of not being able to allocate yet. Keep track of the translation. Re-use the translation after the VM has been initialized to not waste KVA and to satisfy the assumption in uart(4) that the handle returned for the low-level console is the same as later returned when the device is probed and attached. 4. In pmap_unmapdev() remove the mapping from the table when called pre-init. Otherwise keep the mapping. During bus probe and attach device resources are mapped and unmapped multiple times, which would have us destroy the mapping used by the low-level console. 5. In pmap_init(), set pmap_initialized to signal that we're not pre-init anymore. On amd64, bring the direct map in sync with the translations created at that time. 6. Implement bus_space_map() and bus_space_unmap() for real: when the tag corresponds to memory space, call the corresponding pmap_mapdev() and pmap_unmapdev() functions to construct and actual handle. 7. In efifb.c and vt_vga.c, remove the crutches and hacks and simply call pmap_mapdev_attr() or bus_space_map() as desired. Notes: 1. uart(4) already used bus_space_map() during low-level console setup but since serial ports have traditionally been I/O port based, the lack of a proper implementation for said function was not a problem. It has always supported memory mapped UARTs for low-level consoles by setting hw.uart.console accordingly. 2. The use of the direct map on amd64 without setting caching attributes has been a bigger problem than previously thought. This change has the fortunate (and unexpected) side-effect of fixing various EFI frame buffer problems (though not all). PR: 191564, 194952 Special thanks to: 1. XipLink, Inc -- generously donated an Intel Bay Trail E3800 based eval board (ADLE3800PC). 2. The FreeBSD Foundation, in particular emaste@ -- for UEFI support in general and testing. 3. Everyone who tested the proposed for PR 191564. 4. jhb@ and kib@ for being a soundboard and applying a clue bat if so needed. Changes: head/sys/amd64/amd64/machdep.c head/sys/amd64/amd64/pmap.c head/sys/conf/files.amd64 head/sys/conf/files.i386 head/sys/dev/vt/hw/efifb/efifb.c head/sys/dev/vt/hw/vga/vt_vga.c head/sys/i386/i386/machdep.c head/sys/i386/i386/pmap.c head/sys/x86/include/bus.h head/sys/x86/x86/bus_machdep.c A commit references this bug: Author: marcel Date: Tue Aug 25 14:39:44 UTC 2015 New revision: 287126 URL: https://svnweb.freebsd.org/changeset/base/287126 Log: MFC r286667 & r286723 Better support memory mapped console devices, such as VGA and EFI frame buffers and memory mapped UARTs. PR: 191564, 194952, 202276 Changes: _U stable/10/ stable/10/sys/amd64/amd64/machdep.c stable/10/sys/amd64/amd64/pmap.c stable/10/sys/conf/files.amd64 stable/10/sys/conf/files.i386 stable/10/sys/dev/vt/hw/efifb/efifb.c stable/10/sys/dev/vt/hw/vga/vt_vga.c stable/10/sys/dev/vt/hw/vga/vt_vga_reg.h stable/10/sys/i386/i386/machdep.c stable/10/sys/i386/i386/pmap.c stable/10/sys/x86/include/bus.h stable/10/sys/x86/x86/bus_machdep.c |
See PR 192324 Intel's BayTrail SoC has 16550-like UARTs with some extra functionality. They appear to require some special configuration as well; presumably the firmware performs this configuration and enables a compatibility mode for CSM booting. Just adding the PCI device IDs is not sufficient. none7@pci0:0:30:3: class=0x078000 card=0x72708086 chip=0x0f0a8086 rev=0x0c hdr=0x00 vendor = 'Intel Corporation' device = 'ValleyView LPIO1 HSUART Controller' class = simple comms cap 01[80] = powerspec 3 supports D0 D3 current D0 none8@pci0:0:30:4: class=0x078000 card=0x72708086 chip=0x0f0c8086 rev=0x0c hdr=0x00 vendor = 'Intel Corporation' device = 'ValleyView LPIO1 HSUART Controller' class = simple comms cap 01[80] = powerspec 3 supports D0 D3 current D0 Related Linux commits are b15e5691 and 29897087