x86: Update cbmem driver
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>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[Modified the comment about overflow a little bit]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index a6e3f62..c930e4a 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -122,6 +122,14 @@
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 8bbe33d..ba3a599 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;
- cursor = cbmem_console_p->buffer_cursor++;
- if (cursor < cbmem_console_p->buffer_size)
- cbmem_console_p->buffer_body[cursor] = data;
+ 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 later, e.g. Linux
+ */
+ if (pos >= cons->size) {
+ pos = 0;
+ flags |= CBMC_OVERFLOW;
+ }
+
+ cons->cursor = flags | pos;
}
void cbmemc_puts(struct stdio_dev *dev, const char *str)
@@ -40,7 +50,6 @@
{
int rc;
struct stdio_dev cons_dev;
- cbmem_console_p = lib_sysinfo.cbmem_cons;
memset(&cons_dev, 0, sizeof(cons_dev));