+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 The ChromiumOS Authors. All rights reserved.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
+ */
+
+#include <console/console.h>
+#include <cbmem.h>
+#include <string.h>
+
+/*
+ * Structure describing console buffer. It is overlaid on a flat memory area,
+ * whith buffer_body covering the extent of the memory. Once the buffer is
+ * full, the cursor keeps going but the data is dropped on the floor. This
+ * allows to tell how much data was lost in the process.
+ */
+struct cbmem_console {
+ u32 buffer_size;
+ u32 buffer_cursor;
+ u8 buffer_body[0];
+} __attribute__ ((__packed__));
+
+#ifdef __PRE_RAM__
+/*
+ * While running from ROM, before DRAM is initialized, some area in cache as
+ * ram space is used for the console buffer storage. The size and location of
+ * the area are defined in the config.
+ */
+#define cbmem_console_p ((struct cbmem_console *)CONFIG_DCACHE_RAM_BASE)
+
+/*
+ * Once DRAM is initialized and the cache as ram mode is disabled, while still
+ * running from ROM, the console buffer in the cache as RAM area becomes
+ * unavailable.
+ *
+ * By this time the console log buffer is already available in
+ * CBMEM. The location at 0x600 is used as the redirect pointer allowing to
+ * find out where the actual console log buffer is.
+ */
+#define CBMEM_CONSOLE_REDIRECT (*((struct cbmem_console **)0x600))
+#else
+
+/*
+ * When running from RAM, a lot of console output is generated before CBMEM is
+ * reinitialized. This static buffer is used to store that output temporarily,
+ * to be concatenated with the CBMEM console buffer contents accumulated
+ * during the ROM stage, once CBMEM becomes available at RAM stage.
+ */
+static u8 static_console[40000];
+static struct cbmem_console *cbmem_console_p;
+#endif
+
+void cbmemc_init(void)
+{
+#ifdef __PRE_RAM__
+ cbmem_console_p->buffer_size = CONFIG_CONSOLE_CAR_BUFFER_SIZE -
+ sizeof(struct cbmem_console);
+#else
+ /*
+ * Initializing before CBMEM is available, use static buffer to store
+ * the log.
+ */
+ cbmem_console_p = (struct cbmem_console *) static_console;
+ cbmem_console_p->buffer_size = sizeof(static_console) -
+ sizeof(struct cbmem_console);
+#endif
+ cbmem_console_p->buffer_cursor = 0;
+}
+
+void cbmemc_tx_byte(unsigned char data)
+{
+ struct cbmem_console *cbm_cons_p = cbmem_console_p;
+ u32 cursor;
+#ifdef __PRE_RAM__
+ /*
+ * This check allows to tell if the cache as RAM mode has been exited
+ * or not. If it has been exited, the real memory is being used
+ * (resulting in the variable on the stack located below
+ * DCACHE_RAM_BASE), use the redirect pointer to find out where the
+ * actual console buffer is.
+ */
+ if ((u32)&cursor < (u32)CONFIG_DCACHE_RAM_BASE)
+ cbm_cons_p = CBMEM_CONSOLE_REDIRECT;
+#endif
+ if (!cbm_cons_p)
+ return;
+
+ cursor = cbm_cons_p->buffer_cursor++;
+ if (cursor < cbm_cons_p->buffer_size)
+ cbm_cons_p->buffer_body[cursor] = data;
+}
+
+/*
+ * Copy the current console buffer (either from the cache as RAM area, or from
+ * the static buffer, pointed at by cbmem_console_p) into the CBMEM console
+ * buffer space (pointed at by new_cons_p), concatenating the copied data with
+ * the CBMEM console buffer contents.
+ *
+ * If there is overflow - add to the destination area a string, reporting the
+ * overflow and the number of dropped charactes.
+ */
+static void copy_console_buffer(struct cbmem_console *new_cons_p)
+{
+ u32 copy_size;
+ u32 cursor = new_cons_p->buffer_cursor;
+ int overflow = cbmem_console_p->buffer_cursor >
+ cbmem_console_p->buffer_size;
+
+ copy_size = overflow ?
+ cbmem_console_p->buffer_size : cbmem_console_p->buffer_cursor;
+
+ memcpy(new_cons_p->buffer_body + cursor,
+ cbmem_console_p->buffer_body,
+ copy_size);
+
+ cursor += copy_size;
+
+ if (overflow) {
+ const char loss_str1[] = "\n\n*** Log truncated, ";
+ const char loss_str2[] = " characters dropped. ***\n\n";
+ u32 dropped_chars = cbmem_console_p->buffer_cursor - copy_size;
+
+ /*
+ * When running from ROM sprintf is not available, a simple
+ * itoa implementation is used instead.
+ */
+ int got_first_digit = 0;
+
+ /* Way more than possible number of dropped characters. */
+ u32 mult = 100000;
+
+ strcpy((char *)new_cons_p->buffer_body + cursor, loss_str1);
+ cursor += sizeof(loss_str1) - 1;
+
+ while (mult) {
+ int digit = dropped_chars / mult;
+ if (got_first_digit || digit) {
+ new_cons_p->buffer_body[cursor++] = digit + '0';
+ dropped_chars %= mult;
+ /* Excessive, but keeps it simple */
+ got_first_digit = 1;
+ }
+ mult /= 10;
+ }
+
+ strcpy((char *)new_cons_p->buffer_body + cursor, loss_str2);
+ cursor += sizeof(loss_str2) - 1;
+ }
+ new_cons_p->buffer_cursor = cursor;
+}
+
+void cbmemc_reinit(void)
+{
+ struct cbmem_console *cbm_cons_p;
+
+#ifdef __PRE_RAM__
+ cbm_cons_p = cbmem_add(CBMEM_ID_CONSOLE,
+ CONFIG_CONSOLE_CBMEM_BUFFER_SIZE);
+ if (!cbm_cons_p) {
+ CBMEM_CONSOLE_REDIRECT = NULL;
+ return;
+ }
+
+ cbm_cons_p->buffer_size = CONFIG_CONSOLE_CBMEM_BUFFER_SIZE -
+ sizeof(struct cbmem_console);
+
+ cbm_cons_p->buffer_cursor = 0;
+
+ copy_console_buffer(cbm_cons_p);
+
+ CBMEM_CONSOLE_REDIRECT = cbm_cons_p;
+#else
+ cbm_cons_p = cbmem_find(CBMEM_ID_CONSOLE);
+
+ if (!cbm_cons_p)
+ return;
+
+ copy_console_buffer(cbm_cons_p);
+
+ cbmem_console_p = cbm_cons_p;
+#endif
+}
projects / coreboot.git / commitdiff