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@chromium.org ---
Changes in v4: - Add some comments to help understand the overflow mechanism
Changes in v2: - Update to support the new overflow mechanism
drivers/misc/Kconfig | 8 +++++++ drivers/misc/cbmem_console.c | 43 ++++++++++++++++++++++-------------- 2 files changed, 34 insertions(+), 17 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..3cbe9fb1a46a 100644 --- a/drivers/misc/cbmem_console.c +++ b/drivers/misc/cbmem_console.c @@ -5,27 +5,37 @@
#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; + uint pos, flags; + + if (!sysinfo) + return; + cons = sysinfo->cbmem_cons; + if (!cons) + return; + + pos = cons->cursor & CBMC_CURSOR_MASK; + + /* preserve the overflow flag if present */ + flags = cons->cursor & ~CBMC_CURSOR_MASK; + + cons->body[pos++] = data; + + /* + * Deal with overflow - the flag may be cleared by another program which + * reads the buffer out, e.g. Linux + */ + if (pos >= cons->size) { + pos = 0; + flags |= CBMC_OVERFLOW; + }
- cursor = cbmem_console_p->buffer_cursor++; - if (cursor < cbmem_console_p->buffer_size) - cbmem_console_p->buffer_body[cursor] = data; + cons->cursor = flags | pos; }
void cbmemc_puts(struct stdio_dev *dev, const char *str) @@ -40,7 +50,6 @@ 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));