[PATCH] x86: Update cbmem driver

[Simon Glass]

+Paul Menzel <pmenzel at molgen.mpg.de>

On Sun, 13 Aug 2023 at 14:10, Simon Glass <sjg at chromium.org> wrote:
>
> This driver is not actually built since a Kconfig was never created for
> it.
>
> Add a Kconfig (which is already implied by COREBOOT) and update the
> implementation to avoid using unnecessary memory. Drop the #ifdef at the
> top since we can rely on Kconfig to get that right.
>
> To enable it (in addition to serial and video), use:
>
>    setenv stdout serial,vidconsole,cbmem
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  drivers/misc/Kconfig         |  8 ++++++++
>  drivers/misc/cbmem_console.c | 26 +++++++++-----------------
>  2 files changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index b9f5c7a37aed..3df57a5bfbd9 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -122,6 +122,14 @@ config VEXPRESS_CONFIG
>           configuration bus on the Arm Versatile Express boards via
>           a sysreg driver.
>
> +config CBMEM_CONSOLE
> +       bool "Write console output to coreboot cbmem"
> +       depends on X86
> +       help
> +         Enables console output to the cbmem console, which is a memory
> +         region set up by coreboot to hold a record of all console output.
> +         Enable this only if booting from coreboot.
> +
>  config CMD_CROS_EC
>         bool "Enable crosec command"
>         depends on CROS_EC
> diff --git a/drivers/misc/cbmem_console.c b/drivers/misc/cbmem_console.c
> index 8bbe33d414da..6ae1389a23e0 100644
> --- a/drivers/misc/cbmem_console.c
> +++ b/drivers/misc/cbmem_console.c
> @@ -5,27 +5,20 @@
>
>  #include <common.h>
>  #include <console.h>
> -#ifndef CONFIG_SYS_COREBOOT
> -#error This driver requires coreboot
> -#endif
> -
>  #include <asm/cb_sysinfo.h>
>
> -struct cbmem_console {
> -       u32 buffer_size;
> -       u32 buffer_cursor;
> -       u8  buffer_body[0];
> -}  __attribute__ ((__packed__));
> -
> -static struct cbmem_console *cbmem_console_p;
> -
>  void cbmemc_putc(struct stdio_dev *dev, char data)
>  {
> -       int cursor;
> +       const struct sysinfo_t *sysinfo = cb_get_sysinfo();
> +       struct cbmem_console *cons = sysinfo ? sysinfo->cbmem_cons : NULL;
> +       int pos;
> +
> +       if (!cons)
> +               return;
>
> -       cursor = cbmem_console_p->buffer_cursor++;
> -       if (cursor < cbmem_console_p->buffer_size)
> -               cbmem_console_p->buffer_body[cursor] = data;
> +       pos = cons->cursor++;
> +       if (pos < cons->size)
> +               cons->body[pos] = data;
>  }
>
>  void cbmemc_puts(struct stdio_dev *dev, const char *str)
> @@ -40,7 +33,6 @@ int cbmemc_init(void)
>  {
>         int rc;
>         struct stdio_dev cons_dev;
> -       cbmem_console_p = lib_sysinfo.cbmem_cons;
>
>         memset(&cons_dev, 0, sizeof(cons_dev));
>
> --
> 2.41.0.640.ga95def55d0-goog
>