[syslinux] [PATCH 0/1] dprintf: add debug console support

Geert Stappers stappers at stappers.nl
Sun Feb 8 08:41:58 PST 2015

On Sun, Feb 08, 2015 at 09:13:02AM -0700, Jonathan Boeing via Syslinux wrote:
> This patch adds support for printing messages through a debug console.  QEMU,
> for example, supports this through the debugcon facility.  The benefit is that
> it's *much* faster than printing over a serial port.
> To print to I/O port 0x402 (the default used by SeaBIOS and OVMF),
> add "-DDEBUG_IO_PORT=0x402 -DCORE_DEBUG=1" to the build CFLAGS.
> To enable a debug console in QEMU that listens to I/O port 0x402 and prints to
> stdio, add "-debugcon stdio -global isa-debugcon.iobase=0x402" to the QEMU
> command line.

When enabled, what will the effect on real hardware without the diagnostic hardware ?

When enabled, what will the effect on real hardware ?

What (real) diagnostic hardware is adviced?

Oops, I should have start with:

Thank you for providing these development tools.

Geert Stappers

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