Hi Simon,
On Thu, Aug 17, 2023 at 9:58 AM Simon Glass <s...@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 <s...@chromium.org>
> ---
>
> (no changes since v2)
>
> Changes in v2:
> - Update to support the new overflow mechanism
>
> drivers/misc/Kconfig | 8 ++++++++
> drivers/misc/cbmem_console.c | 38 +++++++++++++++++++-----------------
> 2 files changed, 28 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index a6e3f62ecb09..c930e4a361bf 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..7a47a814f638 100644
> --- a/drivers/misc/cbmem_console.c
> +++ b/drivers/misc/cbmem_console.c
> @@ -5,27 +5,30 @@
>
> #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;
> -
> - cursor = cbmem_console_p->buffer_cursor++;
> - if (cursor < cbmem_console_p->buffer_size)
> - cbmem_console_p->buffer_body[cursor] = data;
> + const struct sysinfo_t *sysinfo = cb_get_sysinfo();
> + struct cbmem_console *cons;
> + uint pos, flags;
> +
> + if (!sysinfo)
> + return;
> + cons = sysinfo->cbmem_cons;
> + if (!cons)
> + return;
> +
> + pos = cons->cursor & CBMC_CURSOR_MASK;
> + flags = cons->cursor & ~CBMC_CURSOR_MASK;
This line does not seem useful to me, as we don't use the extracted
flag from the higher bits of cons->cursor.
I guess we can just drop it.
> +
> + cons->body[pos++] = data;
> + if (pos >= cons->size) {
> + pos = 0;
> + flags |= CBMC_OVERFLOW;
Who is supposed to clear the overflow flag?
> + }
> +
> + cons->cursor = flags | pos;
> }
>
> void cbmemc_puts(struct stdio_dev *dev, const char *str)
> @@ -40,7 +43,6 @@ 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));
>
> --
Regards,
Bin
