/* * This file is part of the coreboot project. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #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; }