linux.git/arch/powerpc/kernel/udbg.c, branch v3.0

powerpc: Add early debug for WSP platforms

2011-05-06T03:32:41+00:00

Signed-off-by: Jack Miller 
Signed-off-by: Michael Ellerman 
Signed-off-by: Benjamin Herrenschmidt

powerpc: gamecube/wii: early debugging using usbgecko

2009-12-13T05:24:31+00:00

Add support for using the USB Gecko adapter as an early debugging
console on the Nintendo GameCube and Wii video game consoles.
The USB Gecko is a 3rd party memory card interface adapter that provides
a EXI (External Interface) to USB serial converter.

Signed-off-by: Albert Herranz 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Grant Likely

powerpc/udbg: Fix lost byte during console handover; change LFCR to CRLF

2009-03-11T06:11:34+00:00

When the console is on a serial port to be driven by serial8250, a
character can be lost from the end of the first line in the two-line
sequence

	serial8250.0: ttyS0 at MMIO 0xe0004500 (irq = 42) is a 16550A
	console handover: boot [udbg0] -> real [ttyS0]

This happens because udbg_puts or udbg_write stuff the last byte of
the line into the Tx FIFO and return, whereupon the serial8250
initialization code immediately empties that FIFO.  The fix: udbg_puts
and udbg_write now wait for the Tx FIFO to clear before returning.
This delays the system by one additional serial frame time for each
line written by udbg, but the effect is not noticeable, a cumulative
17 milliseconds for 200 lines of early printk output at 115200 baud.

Also, the routines in udbg_16550.c now emit CRLF instead of LFCR.
Linux makes a point of emitting CRLF because, when serial output is
captured to a file, LFCR sequences can confuse text editors.  See
http://lkml.org/lkml/2006/2/4/50 for some history.

Signed-off-by: Andrew Klossner 
Signed-off-by: Benjamin Herrenschmidt

[POWERPC] Mark udbg console as CON_ANYTIME, ie. callable early in boot

2008-04-24T11:08:11+00:00

The udbg console should be safe to call basically at any time after boot.
It does not need any per-cpu resources or for the cpu to be online, as
long as there is a udbg_putc routine hooked up it should work. So mark it
as CON_ANYTIME.

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras

[POWERPC] Set udbg_console index to 0

2008-04-24T11:08:11+00:00

Because the udbg_console has CON_ENABLED set, it's possible that when we
register it with the console code the index won't be set. This leads to
slightly confusing boot messages like:

[    0.000000] console [udbg-1] enabled

We could remove CON_ENABLED, but we don't want to do that, we always
want the udbg console to be activated, even if the user specified some
other console on the command line.

The simplest fix seems to be just to set the index to 0 by hand. There
is no issue with duplicate udbg consoles, as we guard against registering
multiple times in register_early_udbg_console().

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras

[POWERPC] 4xx: Add early udbg support for 40x processors

2007-12-23T19:13:03+00:00

This adds some basic real mode based early udbg support for 40x
in order to debug things more easily

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Josh Boyer

[POWERPC] Early debug forces console log level to max

2007-12-11T04:43:35+00:00

This makes the early debug option force the console loglevel
to the max.  The early debug option is meant to catch messages very
early in the kernel boot process, in many cases, before the kernel
has a chance to parse the "debug" command line argument.  Thus it
makes sense when CONFIG_PPC_EARLY_DEBUG is set, to force the console
log level to the max at boot time.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Paul Mackerras

[POWERPC] Add early debug console for CPM serial ports.

2007-10-04T01:35:43+00:00

This code assumes that the ports have been previously set up, with
buffers in DPRAM.

Signed-off-by: Scott Wood 
Acked-by: David Gibson 
Signed-off-by: Kumar Gala

[POWREPC] Fixup a number of modpost warnings on ppc32

2007-07-26T05:16:21+00:00

Fixed the following warnings:

WARNING: vmlinux.o(.text+0x2934): Section mismatch: reference to .init.text:__alloc_bootmem (between 'irq_alloc_host' and 'irq_set_default_host')
WARNING: vmlinux.o(.text+0xb2aa): Section mismatch: reference to .init.data:boot_command_line (between 'register_early_udbg_console' and 'udbg_printf')
WARNING: vmlinux.o(.text+0xb2b2): Section mismatch: reference to .init.data:boot_command_line (between 'register_early_udbg_console' and 'udbg_printf')
WARNING: vmlinux.o(.text+0xe354): Section mismatch: reference to .init.text:__alloc_bootmem (between 'pcibios_alloc_controller' and 'pci_domain_nr')
WARNING: vmlinux.o(.text+0x12768): Section mismatch: reference to .init.text:update_bridge_resource (between 'quirk_fsl_pcie_transparent' and 'indirect_read_config')
WARNING: vmlinux.o(.text+0x127a8): Section mismatch: reference to .init.text:update_bridge_resource (between 'quirk_fsl_pcie_transparent' and 'indirect_read_config')
WARNING: vmlinux.o(.text+0x17566c): Section mismatch: reference to .init.text:pcibios_fixup_bus (between 'pci_scan_child_bus' and 'pci_scan_bus_parented')

Signed-off-by: Kumar Gala

[POWERPC] Fix console output getting dropped on platforms without udbg_putc

2007-06-14T01:56:17+00:00

Previously, registering this early console would just result
in dropping early buffered printk output until a udbg_putc
was registered.

However, commit 69331af79cf29e26d1231152a172a1a10c2df511
clears the CON_PRINTBUFFER flag on the main console when a
CON_BOOT (early) console has been registered, resulting in
the buffered messages never being displayed to the user.

This fixes the problem by making sure we don't register udbg_console
on platforms that don't implement udbg_putc.

Signed-off-by: Milton Miller 
Acked-by: Mark A. Greer 
Signed-off-by: Paul Mackerras