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authorDaisuke Nojiri <dnojiri@chromium.org>2015-01-23 10:06:19 -0800
committerPatrick Georgi <pgeorgi@google.com>2015-04-17 09:57:00 +0200
commita6712f3166f1a9e896f7ff0d4ef6216d7b9d081a (patch)
treeae7f723994b7e8eefd92eee0a01dc7430c0ff01b
parent105f5b737bf8de88e37ed991d7469e84cef17c45 (diff)
downloadcoreboot-a6712f3166f1a9e896f7ff0d4ef6216d7b9d081a.tar.xz
broadcom/cygnus: add new SoC driver
This commit covers bootblock and romstage. BUG=none BRANCH=tot TEST=ran emerge-purin coreboot Change-Id: I88e2dffb9e46ba5b066190e844a6a7302adcfdc7 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: b3af6343a74263f086fe82c600559e8204e7dec0 Original-Change-Id: I447ed5f6ed181cfc9d5521b8c57e5fe0036a3f71 Original-Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/242854 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9750 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
-rw-r--r--src/soc/Makefile.inc1
-rw-r--r--src/soc/broadcom/Makefile.inc20
-rw-r--r--src/soc/broadcom/cygnus/Kconfig43
-rw-r--r--src/soc/broadcom/cygnus/Makefile.inc50
-rw-r--r--src/soc/broadcom/cygnus/bootblock.c29
-rw-r--r--src/soc/broadcom/cygnus/cbmem.c26
-rw-r--r--src/soc/broadcom/cygnus/i2c.c32
-rw-r--r--src/soc/broadcom/cygnus/include/soc/gpio.h8
-rw-r--r--src/soc/broadcom/cygnus/include/soc/i2c.h25
-rw-r--r--src/soc/broadcom/cygnus/include/soc/memlayout.ld41
-rw-r--r--src/soc/broadcom/cygnus/include/soc/sdram.h25
-rw-r--r--src/soc/broadcom/cygnus/monotonic_timer.c24
-rw-r--r--src/soc/broadcom/cygnus/romstage.c74
-rw-r--r--src/soc/broadcom/cygnus/sdram.c25
-rw-r--r--src/soc/broadcom/cygnus/spi.c41
-rw-r--r--src/soc/broadcom/cygnus/uart.c42
16 files changed, 506 insertions, 0 deletions
diff --git a/src/soc/Makefile.inc b/src/soc/Makefile.inc
index b722323440..bbcfd2c81b 100644
--- a/src/soc/Makefile.inc
+++ b/src/soc/Makefile.inc
@@ -1,6 +1,7 @@
################################################################################
## Subdirectories
################################################################################
+subdirs-y += broadcom
subdirs-y += imgtec
subdirs-y += intel
subdirs-y += marvell
diff --git a/src/soc/broadcom/Makefile.inc b/src/soc/broadcom/Makefile.inc
new file mode 100644
index 0000000000..165f923032
--- /dev/null
+++ b/src/soc/broadcom/Makefile.inc
@@ -0,0 +1,20 @@
+##
+## 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.
+##
+## 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
+##
+
+subdirs-$(CONFIG_SOC_BROADCOM_CYGNUS) += cygnus
diff --git a/src/soc/broadcom/cygnus/Kconfig b/src/soc/broadcom/cygnus/Kconfig
new file mode 100644
index 0000000000..2f5ad21bc3
--- /dev/null
+++ b/src/soc/broadcom/cygnus/Kconfig
@@ -0,0 +1,43 @@
+##
+## This file is part of the coreboot project.
+##
+## Copyright 2014 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.
+##
+## 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
+##
+
+config SOC_BROADCOM_CYGNUS
+ bool
+ default n
+ select ARCH_BOOTBLOCK_ARMV7
+ select ARCH_RAMSTAGE_ARMV7
+ select ARCH_ROMSTAGE_ARMV7
+ select ARCH_VERSTAGE_ARMV7
+ select BOOTBLOCK_CONSOLE
+ select CPU_HAS_BOOTBLOCK_INIT
+ select DYNAMIC_CBMEM
+ select EARLY_CONSOLE
+ select GENERIC_UDELAY
+ select HAVE_MONOTONIC_TIMER
+ select HAVE_UART_MEMORY_MAPPED
+ select HAVE_UART_SPECIAL
+ select RETURN_FROM_VERSTAGE
+
+if SOC_BROADCOM_CYGNUS
+
+config BOOTBLOCK_CPU_INIT
+ string
+ default "soc/broadcom/cygnus/bootblock.c"
+
+endif
diff --git a/src/soc/broadcom/cygnus/Makefile.inc b/src/soc/broadcom/cygnus/Makefile.inc
new file mode 100644
index 0000000000..4d122819a4
--- /dev/null
+++ b/src/soc/broadcom/cygnus/Makefile.inc
@@ -0,0 +1,50 @@
+##
+## This file is part of the coreboot project.
+##
+## Copyright 2014 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.
+##
+## 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
+##
+
+bootblock-y += bootblock.c
+bootblock-y += cbmem.c
+bootblock-y += i2c.c
+bootblock-y += monotonic_timer.c
+bootblock-$(CONFIG_SPI_FLASH) += spi.c
+bootblock-$(CONFIG_CONSOLE_SERIAL) += uart.c
+
+verstage-y += i2c.c
+verstage-y += monotonic_timer.c
+verstage-$(CONFIG_SPI_FLASH) += spi.c
+verstage-$(CONFIG_CONSOLE_SERIAL) += uart.c
+
+romstage-y += cbmem.c
+romstage-y += i2c.c
+romstage-y += monotonic_timer.c
+romstage-y += romstage.c
+romstage-y += sdram.c
+romstage-$(CONFIG_SPI_FLASH) += spi.c
+romstage-$(CONFIG_CONSOLE_SERIAL) += uart.c
+
+ramstage-y += cbmem.c
+ramstage-y += i2c.c
+ramstage-y += monotonic_timer.c
+ramstage-$(CONFIG_SPI_FLASH) += spi.c
+ramstage-$(CONFIG_CONSOLE_SERIAL) += uart.c
+
+CPPFLAGS_common += -Isrc/soc/broadcom/cygnus/include/
+
+$(objcbfs)/bootblock.bin: $(objcbfs)/bootblock.elf
+ @printf " OBJCOPY $(subst $(obj)/,,$(@))\n"
+ $(OBJCOPY_bootblock) -O binary $< $@
diff --git a/src/soc/broadcom/cygnus/bootblock.c b/src/soc/broadcom/cygnus/bootblock.c
new file mode 100644
index 0000000000..37edf7f771
--- /dev/null
+++ b/src/soc/broadcom/cygnus/bootblock.c
@@ -0,0 +1,29 @@
+/*
+ * 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.
+ *
+ * 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 <bootblock_common.h>
+#include <console/console.h>
+
+void bootblock_soc_init(void)
+{
+ /*
+ * typically, this is the place where mmu is initialized to enable
+ * cache. it helps speed up vboot verification.
+ */
+}
diff --git a/src/soc/broadcom/cygnus/cbmem.c b/src/soc/broadcom/cygnus/cbmem.c
new file mode 100644
index 0000000000..4532b7e01c
--- /dev/null
+++ b/src/soc/broadcom/cygnus/cbmem.c
@@ -0,0 +1,26 @@
+/*
+ * 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.
+ *
+ * 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 <cbmem.h>
+#include <stddef.h>
+
+void *cbmem_top(void)
+{
+ return NULL;
+}
diff --git a/src/soc/broadcom/cygnus/i2c.c b/src/soc/broadcom/cygnus/i2c.c
new file mode 100644
index 0000000000..a6865b9b33
--- /dev/null
+++ b/src/soc/broadcom/cygnus/i2c.c
@@ -0,0 +1,32 @@
+/*
+ * 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.
+ *
+ * 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 <device/i2c.h>
+#include <soc/i2c.h>
+
+int platform_i2c_transfer(unsigned bus, struct i2c_seg *segments, int seg_count)
+{
+ return 0;
+}
+
+void i2c_init(unsigned int bus, unsigned int hz)
+{
+ printk(BIOS_INFO, "i2c initialization is not implemented\n");
+}
diff --git a/src/soc/broadcom/cygnus/include/soc/gpio.h b/src/soc/broadcom/cygnus/include/soc/gpio.h
new file mode 100644
index 0000000000..2d9d8f4911
--- /dev/null
+++ b/src/soc/broadcom/cygnus/include/soc/gpio.h
@@ -0,0 +1,8 @@
+#ifndef __SOC_BROADCOM_CYGNUS_GPIO_H__
+#define __SOC_BROADCOM_CYGNUS_GPIO_H__
+
+#include <types.h>
+
+typedef u32 gpio_t;
+
+#endif /* __SOC_BROADCOM_CYGNUS_GPIO_H__ */
diff --git a/src/soc/broadcom/cygnus/include/soc/i2c.h b/src/soc/broadcom/cygnus/include/soc/i2c.h
new file mode 100644
index 0000000000..18b6eec90a
--- /dev/null
+++ b/src/soc/broadcom/cygnus/include/soc/i2c.h
@@ -0,0 +1,25 @@
+/*
+ * 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.
+ *
+ * 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
+ */
+
+#ifndef __SOC_BROADCOM_CYGNUS_I2C_H__
+#define __SOC_BROADCOM_CYGNUS_I2C_H__
+
+void i2c_init(unsigned int bus, unsigned int hz);
+
+#endif /* __SOC_BROADCOM_CYGNUS_I2C_H__ */
diff --git a/src/soc/broadcom/cygnus/include/soc/memlayout.ld b/src/soc/broadcom/cygnus/include/soc/memlayout.ld
new file mode 100644
index 0000000000..41d13fd7c5
--- /dev/null
+++ b/src/soc/broadcom/cygnus/include/soc/memlayout.ld
@@ -0,0 +1,41 @@
+/*
+ * 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.
+ *
+ * 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 <memlayout.h>
+#include <vendorcode/google/chromeos/memlayout.h>
+
+#include <arch/header.ld>
+
+SECTIONS
+{
+ DRAM_START(0x00000000)
+ RAMSTAGE(0x00200000, 128K)
+ POSTRAM_CBFS_CACHE(0x01000000, 1M)
+
+ SRAM_START(0x61000000)
+ TTB(0x61000000, 16K)
+ BOOTBLOCK(0x61004000, 16K)
+ PRERAM_CBMEM_CONSOLE(0x61008000, 4K)
+ VBOOT2_WORK(0x61009000, 12K)
+ OVERLAP_VERSTAGE_ROMSTAGE(0x6100C000, 40K)
+ PRERAM_CBFS_CACHE(0x61016000, 1K)
+ CBFS_HEADER_OFFSET(0x61016800)
+ STACK(0x61017800, 4K)
+ SRAM_END(0x610040000)
+}
diff --git a/src/soc/broadcom/cygnus/include/soc/sdram.h b/src/soc/broadcom/cygnus/include/soc/sdram.h
new file mode 100644
index 0000000000..573364dfe3
--- /dev/null
+++ b/src/soc/broadcom/cygnus/include/soc/sdram.h
@@ -0,0 +1,25 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 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.
+ *
+ * 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
+ */
+
+#ifndef __SOC_BROADCOM_CYGNUS_SDRAM_H__
+#define __SOC_BROADCOM_CYGNUS_SDRAM_H__
+
+void sdram_init(void);
+
+#endif /* __SOC_BROADCOM_CYGNUS_SDRAM_H__ */
diff --git a/src/soc/broadcom/cygnus/monotonic_timer.c b/src/soc/broadcom/cygnus/monotonic_timer.c
new file mode 100644
index 0000000000..67694f9947
--- /dev/null
+++ b/src/soc/broadcom/cygnus/monotonic_timer.c
@@ -0,0 +1,24 @@
+/*
+ * 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.
+ *
+ * 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 <timer.h>
+
+void timer_monotonic_get(struct mono_time *mt)
+{
+}
diff --git a/src/soc/broadcom/cygnus/romstage.c b/src/soc/broadcom/cygnus/romstage.c
new file mode 100644
index 0000000000..e581a63356
--- /dev/null
+++ b/src/soc/broadcom/cygnus/romstage.c
@@ -0,0 +1,74 @@
+/*
+ * 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.
+ *
+ * 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 <arch/cache.h>
+#include <arch/exception.h>
+#include <arch/stages.h>
+#include <armv7.h>
+#include <cbfs.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <delay.h>
+#include <program_loading.h>
+#include <soc/sdram.h>
+#include <stdlib.h>
+#include <symbols.h>
+#include <timestamp.h>
+#include <types.h>
+#include <vendorcode/google/chromeos/chromeos.h>
+
+void main(void)
+{
+#if CONFIG_COLLECT_TIMESTAMPS
+ uint64_t start_romstage_time;
+ uint64_t before_dram_time;
+ uint64_t after_dram_time;
+ uint64_t base_time = timestamp_get();
+ start_romstage_time = timestamp_get();
+#endif
+
+ console_init();
+
+#if CONFIG_COLLECT_TIMESTAMPS
+ before_dram_time = timestamp_get();
+#endif
+
+ sdram_init();
+
+#if CONFIG_COLLECT_TIMESTAMPS
+ after_dram_time = timestamp_get();
+#endif
+
+ mmu_init();
+ mmu_config_range(0, 4096, DCACHE_OFF);
+ dcache_mmu_enable();
+
+ cbmem_initialize_empty();
+
+#if CONFIG_COLLECT_TIMESTAMPS
+ timestamp_init(base_time);
+ timestamp_add(TS_START_ROMSTAGE, start_romstage_time);
+ timestamp_add(TS_BEFORE_INITRAM, before_dram_time);
+ timestamp_add(TS_AFTER_INITRAM, after_dram_time);
+
+ timestamp_add_now(TS_END_ROMSTAGE);
+#endif
+
+ run_ramstage();
+}
diff --git a/src/soc/broadcom/cygnus/sdram.c b/src/soc/broadcom/cygnus/sdram.c
new file mode 100644
index 0000000000..d9b45c0d43
--- /dev/null
+++ b/src/soc/broadcom/cygnus/sdram.c
@@ -0,0 +1,25 @@
+/*
+ * 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.
+ *
+ * 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 <soc/sdram.h>
+
+void sdram_init(void)
+{
+ printk(BIOS_INFO, "sdram initialization is not implemented\n");
+}
diff --git a/src/soc/broadcom/cygnus/spi.c b/src/soc/broadcom/cygnus/spi.c
new file mode 100644
index 0000000000..16e09ae79f
--- /dev/null
+++ b/src/soc/broadcom/cygnus/spi.c
@@ -0,0 +1,41 @@
+/*
+ * 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.
+ *
+ * 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 <stddef.h>
+#include <spi-generic.h>
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs)
+{
+ return NULL;
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+}
+
+int spi_xfer(struct spi_slave *slave, const void *dout,
+ unsigned out_bytes, void *din, unsigned in_bytes)
+{
+ return 0;
+}
diff --git a/src/soc/broadcom/cygnus/uart.c b/src/soc/broadcom/cygnus/uart.c
new file mode 100644
index 0000000000..70b4a2ef5f
--- /dev/null
+++ b/src/soc/broadcom/cygnus/uart.c
@@ -0,0 +1,42 @@
+/*
+ * 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.
+ *
+ * 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 <boot/coreboot_tables.h>
+#include <console/uart.h>
+
+void uart_init(int idx)
+{
+}
+
+void uart_tx_byte(int idx, unsigned char data)
+{
+}
+
+void uart_tx_flush(int idx)
+{
+}
+
+unsigned char uart_rx_byte(int idx)
+{
+ return '\0';
+}
+
+void uart_fill_lb(void *data)
+{
+}