coreboot-kgpe-d16/payloads/libpayload/drivers/cbmem_console.c

140 lines
4.2 KiB
C

/*
*
* Copyright (c) 2012 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <libpayload.h>
#include <stdint.h>
struct cbmem_console {
uint32_t size;
uint32_t cursor;
uint8_t body[];
} __packed;
#define CURSOR_MASK ((1 << 28) - 1)
#define OVERFLOW (1 << 31)
static uintptr_t cbmem_console_p;
static struct console_output_driver cbmem_console_driver =
{
.write = &cbmem_console_write,
};
static void do_write(const void *buffer, size_t count)
{
struct cbmem_console *const cbmem_cons = phys_to_virt(cbmem_console_p);
memcpy(cbmem_cons->body + (cbmem_cons->cursor & CURSOR_MASK), buffer, count);
cbmem_cons->cursor += count;
}
void cbmem_console_init(void)
{
const struct cbmem_console *const cbmem_cons = phys_to_virt(lib_sysinfo.cbmem_cons);
cbmem_console_p = lib_sysinfo.cbmem_cons;
if (cbmem_console_p && cbmem_cons->size)
console_add_output_driver(&cbmem_console_driver);
}
void cbmem_console_write(const void *buffer, size_t count)
{
struct cbmem_console *const cbmem_cons = phys_to_virt(cbmem_console_p);
while ((cbmem_cons->cursor & CURSOR_MASK) + count >=
cbmem_cons->size) {
size_t still_fits = cbmem_cons->size - (cbmem_cons->cursor & CURSOR_MASK);
do_write(buffer, still_fits);
cbmem_cons->cursor &= ~CURSOR_MASK;
cbmem_cons->cursor |= OVERFLOW;
buffer += still_fits;
count -= still_fits;
}
do_write(buffer, count);
}
static void snapshot_putc(char *console, uint32_t *cursor, char c)
{
/* This is BIOS_LOG_IS_MARKER() from coreboot. Due to stupid
licensing restrictions, we can't use it directly. */
if (c >= 0x10 && c <= 0x18)
return;
/* Slight memory corruption may occur between reboots and give us a few
unprintable characters like '\0'. Replace them with '?' on output. */
if (!isprint(c) && !isspace(c))
console[*cursor] = '?';
else
console[*cursor] = c;
*cursor += 1;
}
char *cbmem_console_snapshot(void)
{
const struct cbmem_console *const console_p = phys_to_virt(cbmem_console_p);
char *console_c;
uint32_t size, cursor, overflow, newc, oldc;
if (!console_p) {
printf("ERROR: No cbmem console found in coreboot table\n");
return NULL;
}
cursor = console_p->cursor & CURSOR_MASK;
overflow = console_p->cursor & OVERFLOW;
if (!overflow && cursor < console_p->size)
size = cursor;
else
size = console_p->size;
console_c = malloc(size + 1);
if (!console_c) {
printf("ERROR: Not enough memory for console (size = %u)\n",
size);
return NULL;
}
newc = 0;
if (overflow) {
if (cursor >= size) {
printf("ERROR: CBMEM console struct is corrupted\n");
return NULL;
}
for (oldc = cursor; oldc < size; oldc++)
snapshot_putc(console_c, &newc, console_p->body[oldc]);
}
for (oldc = 0; oldc < size && oldc < cursor; oldc++)
snapshot_putc(console_c, &newc, console_p->body[oldc]);
console_c[newc] = '\0';
return console_c;
}