1 files changed, 142 insertions, 0 deletions
diff --git a/src/drivers/spi/flashconsole.c b/src/drivers/spi/flashconsole.c
new file mode 100644
index 0000000000..e73af22951
--- /dev/null
+++ b/src/drivers/spi/flashconsole.c
@@ -0,0 +1,142 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google Inc.
+ *
+ * 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 <arch/early_variables.h>
+#include <region.h>
+#include <boot_device.h>
+#include <fmap.h>
+#include <console/console.h>
+#include <console/flash.h>
+#include <string.h>
+
+#define LINE_BUFFER_SIZE 128
+#define READ_BUFFER_SIZE 0x100
+
+static const struct region_device *g_rdev_ptr CAR_GLOBAL;
+static struct region_device g_rdev CAR_GLOBAL;
+static uint8_t g_line_buffer[LINE_BUFFER_SIZE] CAR_GLOBAL;
+static size_t g_offset CAR_GLOBAL;
+static size_t g_line_offset CAR_GLOBAL;
+
+void flashconsole_init(void)
+{
+	struct region_device *rdev = car_get_var_ptr(&g_rdev);
+	uint8_t buffer[READ_BUFFER_SIZE];
+	size_t size;
+	size_t 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 && offset < size; ) {
+		// Fill the buffer on first iteration
+		if (i == 0) {
+			len = min(READ_BUFFER_SIZE, size - offset);
+			if (rdev_readat(rdev, buffer, offset, len) != len)
+				return;
+		}
+		if (buffer[i] == 0xff) {
+			offset += i;
+			break;
+		}
+		// If we're done, repeat the process for the next sector
+		if (++i == READ_BUFFER_SIZE) {
+			offset += len;
+			i = 0;
+		}
+	}
+	// Make sure there is still space left on the console
+	if (offset >= size) {
+		printk(BIOS_INFO, "No space left on 'console' region in SPI flash\n");
+		return;
+	}
+
+	car_set_var(g_offset, offset);
+	/* Set g_rdev_ptr last so tx_byte doesn't get executed early */
+	car_set_var(g_rdev_ptr, rdev);
+}
+
+void flashconsole_tx_byte(unsigned char c)
+{
+	const struct region_device *rdev = car_get_var(g_rdev_ptr);
+	uint8_t *line_buffer;
+	size_t offset;
+	size_t len;
+	size_t region_size;
+
+	if (!rdev)
+		return;
+
+	line_buffer = car_get_var_ptr(g_line_buffer);
+	offset = car_get_var(g_offset);
+	len = car_get_var(g_line_offset);
+	region_size = region_device_sz(rdev);
+
+	line_buffer[len++] = c;
+	car_set_var(g_line_offset, len);
+
+	if (len >= LINE_BUFFER_SIZE ||
+		offset + len >= region_size || c == '\n') {
+		flashconsole_tx_flush();
+	}
+}
+
+void flashconsole_tx_flush(void)
+{
+	const struct region_device *rdev = car_get_var(g_rdev_ptr);
+	uint8_t *line_buffer = car_get_var_ptr(g_line_buffer);
+	size_t offset = car_get_var(g_offset);
+	size_t len = car_get_var(g_line_offset);
+	size_t region_size;
+
+	if (!rdev)
+		return;
+
+	/* Prevent any recursive loops in case the spi flash driver
+	 * calls printk (in case of transaction timeout or
+	 * any other error while writing) */
+	car_set_var(g_rdev_ptr, NULL);
+
+	region_size = region_device_sz(rdev);
+	if (offset + len >= region_size)
+		len = region_size - offset;
+
+	if (rdev_writeat(rdev, line_buffer, offset, len) != len)
+		rdev = NULL;
+
+	// If the region is full, stop future write attempts
+	if (offset + len >= region_size)
+		rdev = NULL;
+
+	car_set_var(g_offset, offset + len);
+	car_set_var(g_line_offset, 0);
+
+	car_set_var(g_rdev_ptr, rdev);
+}