summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2025-04-07 20:22:14 +0300
committerIngo Molnar <mingo@kernel.org>2025-04-09 12:27:08 +0200
commit996457176bb7c64b3d30996592c754205ec4d3ea (patch)
treeb7bb150634f1f026c6681a3c96c98e26defef90e /Documentation
parent45c2e30bbd64d75559b99f3a5c455129a7a34b06 (diff)
x86/early_printk: Use 'mmio32' for consistency, fix comments
First of all, using 'mmio' prevents proper implementation of 8-bit accessors. Second, it's simply inconsistent with uart8250 set of options. Rename it to 'mmio32'. While at it, remove rather misleading comment in the documentation. From now on mmio32 is self-explanatory and pciserial supports not only 32-bit MMIO accessors. Also, while at it, fix the comment for the "pciserial" case. The comment seems to be a copy'n'paste error when mentioning "serial" instead of "pciserial" (with double quotes). Fix this. With that, move it upper, so we don't calculate 'buf' twice. Fixes: 3181424aeac2 ("x86/early_printk: Add support for MMIO-based UARTs") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Denis Mukhin <dmukhin@ford.com> Link: https://lore.kernel.org/r/20250407172214.792745-1-andriy.shevchenko@linux.intel.com
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt5
1 files changed, 1 insertions, 4 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 76e538c77e31..d9fd26b95b34 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1407,18 +1407,15 @@
earlyprintk=serial[,0x...[,baudrate]]
earlyprintk=ttySn[,baudrate]
earlyprintk=dbgp[debugController#]
+ earlyprintk=mmio32,membase[,{nocfg|baudrate}]
earlyprintk=pciserial[,force],bus:device.function[,{nocfg|baudrate}]
earlyprintk=xdbc[xhciController#]
earlyprintk=bios
- earlyprintk=mmio,membase[,{nocfg|baudrate}]
earlyprintk is useful when the kernel crashes before
the normal console is initialized. It is not enabled by
default because it has some cosmetic problems.
- Only 32-bit memory addresses are supported for "mmio"
- and "pciserial" devices.
-
Use "nocfg" to skip UART configuration, assume
BIOS/firmware has configured UART correctly.