[SeaBIOS] Re: [PATCH] Add an option for debug output on the vga console.

[Paul Menzel]

Dear Karl,

Thank you for your patch.

Am 12.03.22 um 02:04 schrieb Karl Semich:

One nit: Could you please remove the dot/period from the end of the summary.
> Only available if threads are disabled.

Could you please elaborate, why it does not work with enabled threads.
> Only displays after the console has been loaded and from within 32bit
> flat regions of code.

How did you test this?

Kind regards,

Paul
> Signed-off-by: Karl Semich
>
> src/Kconfig      |  9 +++++++++
>   src/bootsplash.c |  9 +++++++++
>   src/output.c     | 32 +++++++++++++++++++++++++-------
>   src/util.h       |  1 +
>   4 files changed, 44 insertions(+), 7 deletions(-)
>
> diff --git a/src/Kconfig b/src/Kconfig
> index 3a8ffa1..5d2c7ab 100644
> --- a/src/Kconfig
> +++ b/src/Kconfig
> @@ -571,6 +571,15 @@ menu "Debugging"
>               provide the 32 bit address. E.g. 0xFEDC6000 for the AMD Kern
>               (a.k.a Hudson UART).
> config DEBUG_VGA_CONSOLE
>    depends on DEBUG_LEVEL != 0 && !THREADS
>    bool "VGA console debugging"
>    default y
>    help
>        Send debugging information to vga console. This is only displayed
>        after the VGA console has loaded, and only in 32 bit flat regions
>        of code. Requires that threads are disabled.
> config DEBUG_IO
>     depends on QEMU_HARDWARE && DEBUG_LEVEL != 0
>     bool "Special IO port debugging"
>
> diff --git a/src/bootsplash.c b/src/bootsplash.c
> index 538b316..2a93c8a 100644
> --- a/src/bootsplash.c
> +++ b/src/bootsplash.c
> @@ -36,6 +36,8 @@ call16_int10(struct bregs *br)
> VGA text / graphics console
>
> ****************************************************************/
>
> +static int VgaConsoleActive = 0;
> void
> enable_vga_console(void)
> {
>
> @@ -47,11 +49,18 @@ enable_vga_console(void)
>       br.ax = 0x0003;
>       call16_int10(&br);
> VgaConsoleActive = 1;
> // Write to screen.
> printf("SeaBIOS (version %s)\n", VERSION);
> display_uuid();
> }
>
> +int vga_console_active(void)
> +{
> return VgaConsoleActive;
>
> +}
> static int
> find_videomode(struct vbe_info *vesa_info, struct vbe_mode_info *mode_info
>                , int width, int height, int bpp_req)
>
> diff --git a/src/output.c b/src/output.c
> index 0184444..27935bc 100644
> --- a/src/output.c
> +++ b/src/output.c
> @@ -17,12 +17,15 @@
>   #include "output.h" // dprintf
>   #include "stacks.h" // call16_int
>   #include "string.h" // memset
> -#include "util.h" // ScreenAndDebug
> +#include "util.h" // ScreenAndDebug vga_console_active
>
> struct putcinfo {
>       void (*func)(struct putcinfo *info, char c);
>   };
>
> +static void __debug_putc(char c);
> +static void __screen_putc(char c);
>
> /****************************************************************
> Debug output
>
> @@ -35,9 +38,8 @@ debug_banner(void)
>       dprintf(1, "BUILD: %s\n", BUILDINFO);
>   }
>
> -// Write a character to debug port(s).
>   static void
> -debug_putc(struct putcinfo *action, char c)
> +__debug_putc(char c)
>   {
>       if (! CONFIG_DEBUG_LEVEL)
>           return;
> @@ -47,6 +49,16 @@ debug_putc(struct putcinfo *action, char c)
>       serial_debug_putc(c);
>   }
>
> +// Write a character to debug port(s).
> +static void
> +debug_putc(struct putcinfo *action, char c)
> +{
> __debug_putc(c);
> if (CONFIG_DEBUG_LEVEL && CONFIG_DEBUG_VGA_CONSOLE && !MODESEGMENT
>    && vga_console_active())
>    __screen_putc(c);
>
> +}
> // Flush any pending output to debug port(s).
> static void
> debug_flush(void)
>
> @@ -86,17 +98,23 @@ screenc(char c)
>       call16_int(0x10, &br);
>   }
>
> -// Handle a character from a printf request.
>   static void
> -screen_putc(struct putcinfo *action, char c)
> +__screen_putc(char c)
>   {
> if (ScreenAndDebug)
>    debug_putc(&debuginfo, c);
> if (c == '\n')
>     screenc('\r');
> screenc(c);
> }
>
> +// Handle a character from a printf request.
> +static void
> +screen_putc(struct putcinfo *action, char c)
> +{
> if (ScreenAndDebug)
>    __debug_putc(c);
> __screen_putc(c);
>
> +}
> static struct putcinfo screeninfo = { screen_putc };
>
> diff --git a/src/util.h b/src/util.h
> index aff8e88..8219e0c 100644
> --- a/src/util.h
> +++ b/src/util.h
> @@ -50,6 +50,7 @@ int boot_lchs_find_ata_device(struct pci_device *pci, int chanid, int slave,
>
> // bootsplash.c
>   void enable_vga_console(void);
> +int vga_console_active(void);
>   void enable_bootsplash(void);
>   void disable_bootsplash(void);