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/* SPDX-License-Identifier: GPL-2.0-only */
/* This file is part of the coreboot project. */
#include <commonlib/helpers.h>
#include <commonlib/region.h>
#include <boot_device.h>
#include <fmap.h>
#include <console/console.h>
#include <console/flash.h>
#include <types.h>
#define LINE_BUFFER_SIZE 128
#define READ_BUFFER_SIZE 0x100
static const struct region_device *rdev_ptr;
static struct region_device rdev;
static uint8_t line_buffer[LINE_BUFFER_SIZE];
static size_t offset;
static size_t line_offset;
void flashconsole_init(void)
{
uint8_t buffer[READ_BUFFER_SIZE];
size_t size;
size_t initial_offset = 0;
size_t len = READ_BUFFER_SIZE;
size_t i;
if (fmap_locate_area_as_rdev_rw("CONSOLE", &rdev)) {
printk(BIOS_INFO, "Can't find 'CONSOLE' area in FMAP\n");
return;
}
size = region_device_sz(&rdev);
/*
* We need to check the region until we find a 0xff indicating
* the end of a previous log write.
* We can't erase the region because one stage would erase the
* data from the previous stage. Also, it looks like doing an
* erase could completely freeze the SPI controller and then
* we can't write anything anymore (apparently might happen if
* the sector is already erased, so we would need to read
* anyways to check if it's all 0xff).
*/
for (i = 0; i < len && initial_offset < size;) {
// Fill the buffer on first iteration
if (i == 0) {
len = MIN(READ_BUFFER_SIZE, size - offset);
if (rdev_readat(&rdev, buffer, initial_offset, len) != len)
return;
}
if (buffer[i] == 0xff) {
initial_offset += i;
break;
}
// If we're done, repeat the process for the next sector
if (++i == READ_BUFFER_SIZE) {
initial_offset += len;
i = 0;
}
}
// Make sure there is still space left on the console
if (initial_offset >= size) {
printk(BIOS_INFO, "No space left on 'console' region in SPI flash\n");
return;
}
offset = initial_offset;
rdev_ptr = &rdev;
}
void flashconsole_tx_byte(unsigned char c)
{
if (!rdev_ptr)
return;
size_t region_size = region_device_sz(rdev_ptr);
line_buffer[line_offset++] = c;
if (line_offset >= LINE_BUFFER_SIZE ||
offset + line_offset >= region_size || c == '\n') {
flashconsole_tx_flush();
}
}
void flashconsole_tx_flush(void)
{
size_t len = line_offset;
size_t region_size;
static int busy;
/* Prevent any recursive loops in case the spi flash driver
* calls printk (in case of transaction timeout or
* any other error while writing) */
if (busy)
return;
if (!rdev_ptr)
return;
busy = 1;
region_size = region_device_sz(rdev_ptr);
if (offset + len >= region_size)
len = region_size - offset;
if (rdev_writeat(&rdev, line_buffer, offset, len) != len)
return;
// If the region is full, stop future write attempts
if (offset + len >= region_size)
return;
offset += len;
line_offset = 0;
busy = 0;
}
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