u-boot/drivers/misc/cbmem_console.c
Simon Glass fb5cfbe17d 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>
2023-09-22 06:03:46 +08:00

64 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2011 The ChromiumOS Authors. All rights reserved.
*/
#include <common.h>
#include <console.h>
#include <asm/cb_sysinfo.h>
void cbmemc_putc(struct stdio_dev *dev, char 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;
/* 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)
{
char c;
while ((c = *str++) != 0)
cbmemc_putc(dev, c);
}
int cbmemc_init(void)
{
int rc;
struct stdio_dev cons_dev;
memset(&cons_dev, 0, sizeof(cons_dev));
strcpy(cons_dev.name, "cbmem");
cons_dev.flags = DEV_FLAGS_OUTPUT; /* Output only */
cons_dev.putc = cbmemc_putc;
cons_dev.puts = cbmemc_puts;
rc = stdio_register(&cons_dev);
return (rc == 0) ? 1 : rc;
}