NAND boot: MPC8536DS support
MPC8536E can support booting from NAND flash which uses the
image u-boot-nand.bin. This image contains two parts: a 4K
NAND loader and a main U-Boot image. The former is appended
to the latter to produce u-boot-nand.bin. The 4K NAND loader
includes the corresponding nand_spl directory, along with the
code twisted by CONFIG_NAND_SPL. The main U-Boot image just
like a general U-Boot image except the parts that included by
CONFIG_SYS_RAMBOOT.
When power on, eLBC will automatically load from bank 0 the
4K NAND loader into the FCM buffer RAM where CPU can execute
the boot code directly. In the first stage, the NAND loader
copies itself to RAM or L2SRAM to free up the FCM buffer RAM,
then loads the main image from NAND flash to RAM or L2SRAM
and boot from it.
This patch implements the NAND loader to load the main image
into L2SRAM, so the main image can configure the RAM by using
SPD EEPROM. In the first stage, the NAND loader copies itself
to the second to last 4K address space, and uses the last 4K
address space as the initial RAM for stack.
Obviously, the size of L2SRAM shouldn't be less than the size
of the image used. If so, the workaround is to generate another
image that includes the code to configure the RAM by SPD and
load it to L2SRAM first, then relocate the main image to RAM
to boot up.
Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/MAKEALL b/MAKEALL
index 776f968..0249058 100755
--- a/MAKEALL
+++ b/MAKEALL
@@ -387,6 +387,7 @@
LIST_85xx=" \
ATUM8548 \
MPC8536DS \
+ MPC8536DS_NAND \
MPC8540ADS \
MPC8540EVAL \
MPC8541CDS \
diff --git a/Makefile b/Makefile
index 9c5b2a5..781db22 100644
--- a/Makefile
+++ b/Makefile
@@ -2446,6 +2446,7 @@
ATUM8548_config: unconfig
@$(MKCONFIG) $(@:_config=) ppc mpc85xx atum8548
+MPC8536DS_NAND_config \
MPC8536DS_36BIT_config \
MPC8536DS_config: unconfig
@$(MKCONFIG) -t $(@:_config=) MPC8536DS ppc mpc85xx mpc8536ds freescale
diff --git a/board/freescale/mpc8536ds/config.mk b/board/freescale/mpc8536ds/config.mk
index c1d0525..d6490b5 100644
--- a/board/freescale/mpc8536ds/config.mk
+++ b/board/freescale/mpc8536ds/config.mk
@@ -23,6 +23,13 @@
#
# mpc8536ds board
#
+ifndef NAND_SPL
+ifeq ($(CONFIG_MK_NAND), y)
+TEXT_BASE = $(CONFIG_RAMBOOT_TEXT_BASE)
+LDSCRIPT := $(TOPDIR)/cpu/$(CPU)/u-boot-nand.lds
+endif
+endif
+
ifndef TEXT_BASE
TEXT_BASE = 0xeff80000
endif
diff --git a/board/freescale/mpc8536ds/tlb.c b/board/freescale/mpc8536ds/tlb.c
index 35a13d4..dc52d7f 100644
--- a/board/freescale/mpc8536ds/tlb.c
+++ b/board/freescale/mpc8536ds/tlb.c
@@ -71,6 +71,17 @@
SET_TLB_ENTRY(1, CONFIG_SYS_NAND_BASE, CONFIG_SYS_NAND_BASE_PHYS,
MAS3_SX|MAS3_SW|MAS3_SR, MAS2_I|MAS2_G,
0, 4, BOOKE_PAGESZ_1M, 1),
+
+#if defined(CONFIG_SYS_RAMBOOT) && defined(CONFIG_SYS_INIT_L2_ADDR)
+ /* *I*G - L2SRAM */
+ SET_TLB_ENTRY(1, CONFIG_SYS_INIT_L2_ADDR, CONFIG_SYS_INIT_L2_ADDR_PHYS,
+ MAS3_SX|MAS3_SW|MAS3_SR, MAS2_I|MAS2_G,
+ 0, 5, BOOKE_PAGESZ_256K, 1),
+ SET_TLB_ENTRY(1, CONFIG_SYS_INIT_L2_ADDR + 0x40000,
+ CONFIG_SYS_INIT_L2_ADDR_PHYS + 0x40000,
+ MAS3_SX|MAS3_SW|MAS3_SR, MAS2_I|MAS2_G,
+ 0, 6, BOOKE_PAGESZ_256K, 1),
+#endif
};
int num_tlb_entries = ARRAY_SIZE(tlb_table);
diff --git a/include/configs/MPC8536DS.h b/include/configs/MPC8536DS.h
index 9d45648..af36986 100644
--- a/include/configs/MPC8536DS.h
+++ b/include/configs/MPC8536DS.h
@@ -31,6 +31,12 @@
#define CONFIG_PHYS_64BIT 1
#endif
+#ifdef CONFIG_MK_NAND
+#define CONFIG_NAND_U_BOOT 1
+#define CONFIG_RAMBOOT_NAND 1
+#define CONFIG_RAMBOOT_TEXT_BASE 0xf8f82000
+#endif
+
/* High Level Configuration Options */
#define CONFIG_BOOKE 1 /* BOOKE */
#define CONFIG_E500 1 /* BOOKE e500 family */
@@ -91,10 +97,21 @@
#define CONFIG_PANIC_HANG /* do not reset board on panic */
/*
+ * Config the L2 Cache as L2 SRAM
+ */
+#define CONFIG_SYS_INIT_L2_ADDR 0xf8f80000
+#ifdef CONFIG_PHYS_64BIT
+#define CONFIG_SYS_INIT_L2_ADDR_PHYS 0xff8f80000ull
+#else
+#define CONFIG_SYS_INIT_L2_ADDR_PHYS CONFIG_SYS_INIT_L2_ADDR
+#endif
+#define CONFIG_SYS_L2_SIZE (512 << 10)
+#define CONFIG_SYS_INIT_L2_END (CONFIG_SYS_INIT_L2_ADDR + CONFIG_SYS_L2_SIZE)
+
+/*
* Base addresses -- Note these are effective addresses where the
* actual resources get mapped (not physical addresses)
*/
-#define CONFIG_SYS_CCSRBAR_DEFAULT 0xff700000 /* CCSRBAR Default */
#define CONFIG_SYS_CCSRBAR 0xffe00000 /* relocated CCSRBAR */
#ifdef CONFIG_PHYS_64BIT
#define CONFIG_SYS_CCSRBAR_PHYS 0xfffe00000ull /* physical addr of CCSRBAR */
@@ -103,6 +120,12 @@
#endif
#define CONFIG_SYS_IMMR CONFIG_SYS_CCSRBAR /* PQII uses CONFIG_SYS_IMMR */
+#if defined(CONFIG_RAMBOOT_NAND) && !defined(CONFIG_NAND_SPL)
+#define CONFIG_SYS_CCSRBAR_DEFAULT CONFIG_SYS_CCSRBAR
+#else
+#define CONFIG_SYS_CCSRBAR_DEFAULT 0xff700000 /* CCSRBAR Default */
+#endif
+
#define CONFIG_SYS_PCI1_ADDR (CONFIG_SYS_CCSRBAR + 0x8000)
#define CONFIG_SYS_PCIE1_ADDR (CONFIG_SYS_CCSRBAR + 0xa000)
#define CONFIG_SYS_PCIE2_ADDR (CONFIG_SYS_CCSRBAR + 0x9000)
@@ -190,10 +213,10 @@
#define CONFIG_SYS_FLASH_BASE_PHYS CONFIG_SYS_FLASH_BASE
#endif
-#define CONFIG_SYS_BR0_PRELIM \
+#define CONFIG_FLASH_BR_PRELIM \
(BR_PHYS_ADDR((CONFIG_SYS_FLASH_BASE_PHYS + 0x8000000)) \
| BR_PS_16 | BR_V)
-#define CONFIG_SYS_OR0_PRELIM 0xf8000ff7
+#define CONFIG_FLASH_OR_PRELIM 0xf8000ff7
#define CONFIG_SYS_BR1_PRELIM \
(BR_PHYS_ADDR(CONFIG_SYS_FLASH_BASE_PHYS) \
@@ -213,6 +236,12 @@
#define CONFIG_SYS_MONITOR_BASE TEXT_BASE /* start of monitor */
+#if defined(CONFIG_SYS_SPL) || defined(CONFIG_RAMBOOT_NAND)
+#define CONFIG_SYS_RAMBOOT
+#else
+#undef CONFIG_SYS_RAMBOOT
+#endif
+
#define CONFIG_FLASH_CFI_DRIVER
#define CONFIG_SYS_FLASH_CFI
#define CONFIG_SYS_FLASH_EMPTY_INFO
@@ -265,6 +294,8 @@
#define PIXIS_VWATCH 0x24 /* Watchdog Register */
#define PIXIS_LED 0x25 /* LED Register */
+#define PIXIS_SPD_SYSCLK 0x7 /* SYSCLK option */
+
/* old pixis referenced names */
#define PIXIS_VCLKH 0x19 /* VELA VCLKH register */
#define PIXIS_VCLKL 0x1A /* VELA VCLKL register */
@@ -282,12 +313,21 @@
#define CONFIG_SYS_MONITOR_LEN (256 * 1024) /* Reserve 256 kB for Mon */
#define CONFIG_SYS_MALLOC_LEN (1024 * 1024) /* Reserved for malloc */
+#ifndef CONFIG_NAND_SPL
#define CONFIG_SYS_NAND_BASE 0xffa00000
#ifdef CONFIG_PHYS_64BIT
#define CONFIG_SYS_NAND_BASE_PHYS 0xfffa00000ull
#else
#define CONFIG_SYS_NAND_BASE_PHYS CONFIG_SYS_NAND_BASE
#endif
+#else
+#define CONFIG_SYS_NAND_BASE 0xfff00000
+#ifdef CONFIG_PHYS_64BIT
+#define CONFIG_SYS_NAND_BASE_PHYS 0xffff00000ull
+#else
+#define CONFIG_SYS_NAND_BASE_PHYS CONFIG_SYS_NAND_BASE
+#endif
+#endif
#define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE,\
CONFIG_SYS_NAND_BASE + 0x40000, \
CONFIG_SYS_NAND_BASE + 0x80000, \
@@ -298,6 +338,16 @@
#define CONFIG_NAND_FSL_ELBC 1
#define CONFIG_SYS_NAND_BLOCK_SIZE (128 * 1024)
+/* NAND boot: 4K NAND loader config */
+#define CONFIG_SYS_NAND_SPL_SIZE 0x1000
+#define CONFIG_SYS_NAND_U_BOOT_SIZE ((512 << 10) - 0x2000)
+#define CONFIG_SYS_NAND_U_BOOT_DST (CONFIG_SYS_INIT_L2_ADDR)
+#define CONFIG_SYS_NAND_U_BOOT_START \
+ (CONFIG_SYS_INIT_L2_ADDR + CONFIG_SYS_NAND_SPL_SIZE)
+#define CONFIG_SYS_NAND_U_BOOT_OFFS (0)
+#define CONFIG_SYS_NAND_U_BOOT_RELOC (CONFIG_SYS_INIT_L2_END - 0x2000)
+#define CONFIG_SYS_NAND_U_BOOT_RELOC_SP ((CONFIG_SYS_INIT_L2_END - 1) & ~0xF)
+
/* NAND flash config */
#define CONFIG_NAND_BR_PRELIM \
(BR_PHYS_ADDR(CONFIG_SYS_NAND_BASE_PHYS) \
@@ -314,8 +364,17 @@
| OR_FCM_TRLX \
| OR_FCM_EHTR)
+#ifdef CONFIG_RAMBOOT_NAND
+#define CONFIG_SYS_BR0_PRELIM CONFIG_NAND_BR_PRELIM /* NAND Base Address */
+#define CONFIG_SYS_OR0_PRELIM CONFIG_NAND_OR_PRELIM /* NAND Options */
+#define CONFIG_SYS_BR2_PRELIM CONFIG_FLASH_BR_PRELIM /* NOR Base Address */
+#define CONFIG_SYS_OR2_PRELIM CONFIG_FLASH_OR_PRELIM /* NOR Options */
+#else
+#define CONFIG_SYS_BR0_PRELIM CONFIG_FLASH_BR_PRELIM /* NOR Base Address */
+#define CONFIG_SYS_OR0_PRELIM CONFIG_FLASH_OR_PRELIM /* NOR Options */
#define CONFIG_SYS_BR2_PRELIM CONFIG_NAND_BR_PRELIM /* NAND Base Address */
#define CONFIG_SYS_OR2_PRELIM CONFIG_NAND_OR_PRELIM /* NAND Options */
+#endif
#define CONFIG_SYS_BR4_PRELIM \
(BR_PHYS_ADDR((CONFIG_SYS_NAND_BASE_PHYS + 0x40000)) \
@@ -536,15 +595,6 @@
#define CONFIG_CMD_EXT2
#endif
-/*
- * USB
- */
-#define CONFIG_CMD_USB
-#define CONFIG_USB_STORAGE
-#define CONFIG_USB_EHCI
-#define CONFIG_USB_EHCI_FSL
-#define CONFIG_EHCI_HCD_INIT_AFTER_RESET
-
#if defined(CONFIG_TSEC_ENET)
#ifndef CONFIG_NET_MULTI
@@ -579,14 +629,23 @@
/*
* Environment
*/
-#define CONFIG_ENV_IS_IN_FLASH 1
-#if CONFIG_SYS_MONITOR_BASE > 0xfff80000
-#define CONFIG_ENV_ADDR 0xfff80000
-#else
-#define CONFIG_ENV_ADDR (CONFIG_SYS_MONITOR_BASE - CONFIG_ENV_SECT_SIZE)
+
+#if defined(CONFIG_SYS_RAMBOOT)
+#if defined(CONFIG_RAMBOOT_NAND)
+ #define CONFIG_ENV_IS_IN_NAND 1
+ #define CONFIG_ENV_SIZE CONFIG_SYS_NAND_BLOCK_SIZE
+ #define CONFIG_ENV_OFFSET ((512 * 1024) + CONFIG_SYS_NAND_BLOCK_SIZE)
#endif
-#define CONFIG_ENV_SIZE 0x2000
-#define CONFIG_ENV_SECT_SIZE 0x20000 /* 128K (one sector) */
+#else
+ #define CONFIG_ENV_IS_IN_FLASH 1
+ #if CONFIG_SYS_MONITOR_BASE > 0xfff80000
+ #define CONFIG_ENV_ADDR 0xfff80000
+ #else
+ #define CONFIG_ENV_ADDR (CONFIG_SYS_MONITOR_BASE - CONFIG_ENV_SECT_SIZE)
+ #endif
+ #define CONFIG_ENV_SIZE 0x2000
+ #define CONFIG_ENV_SECT_SIZE 0x20000 /* 128K (one sector) */
+#endif
#define CONFIG_LOADS_ECHO 1 /* echo on for serial download */
#define CONFIG_SYS_LOADS_BAUD_CHANGE 1 /* allow baudrate change */
diff --git a/nand_spl/board/freescale/mpc8536ds/Makefile b/nand_spl/board/freescale/mpc8536ds/Makefile
new file mode 100644
index 0000000..1d5e319
--- /dev/null
+++ b/nand_spl/board/freescale/mpc8536ds/Makefile
@@ -0,0 +1,127 @@
+#
+# (C) Copyright 2007
+# Stefan Roese, DENX Software Engineering, sr@denx.de.
+#
+# Copyright 2009 Freescale Semiconductor, Inc.
+#
+# See file CREDITS for list of people who contributed to this
+# 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; either version 2 of
+# the License, or (at your option) any later version.
+#
+# 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., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+NAND_SPL := y
+TEXT_BASE := 0xfff00000
+PAD_TO := 0xfff01000
+
+include $(TOPDIR)/config.mk
+
+LDSCRIPT= $(TOPDIR)/cpu/$(CPU)/u-boot-nand_spl.lds
+LDFLAGS = -Bstatic -T $(LDSCRIPT) -Ttext $(TEXT_BASE) $(PLATFORM_LDFLAGS)
+AFLAGS += -DCONFIG_NAND_SPL
+CFLAGS += -DCONFIG_NAND_SPL
+
+SOBJS = start.o resetvec.o
+COBJS = cache.o cpu_init_early.o cpu_init_nand.o fsl_law.o law.o \
+ nand_boot.o nand_boot_fsl_elbc.o ns16550.o tlb.o tlb_table.o
+
+SRCS := $(addprefix $(obj),$(SOBJS:.o=.S) $(COBJS:.o=.c))
+OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS))
+__OBJS := $(SOBJS) $(COBJS)
+LNDIR := $(OBJTREE)/nand_spl/board/$(BOARDDIR)
+
+nandobj := $(OBJTREE)/nand_spl/
+
+ALL = $(nandobj)u-boot-spl $(nandobj)u-boot-spl.bin $(nandobj)u-boot-spl-16k.bin
+
+all: $(obj).depend $(ALL)
+
+$(nandobj)u-boot-spl-16k.bin: $(nandobj)u-boot-spl
+ $(OBJCOPY) ${OBJCFLAGS} --pad-to=$(PAD_TO) -O binary $< $@
+
+$(nandobj)u-boot-spl.bin: $(nandobj)u-boot-spl
+ $(OBJCOPY) ${OBJCFLAGS} -O binary $< $@
+
+$(nandobj)u-boot-spl: $(OBJS)
+ cd $(LNDIR) && $(LD) $(LDFLAGS) $(__OBJS) $(PLATFORM_LIBS) \
+ -Map $(nandobj)u-boot-spl.map \
+ -o $(nandobj)u-boot-spl
+
+# create symbolic links for common files
+
+$(obj)cache.c:
+ @rm -f $(obj)cache.c
+ ln -sf $(SRCTREE)/lib_ppc/cache.c $(obj)cache.c
+
+$(obj)cpu_init_early.c:
+ @rm -f $(obj)cpu_init_early.c
+ ln -sf $(SRCTREE)/cpu/mpc85xx/cpu_init_early.c $(obj)cpu_init_early.c
+
+$(obj)cpu_init_nand.c:
+ @rm -f $(obj)cpu_init_nand.c
+ ln -sf $(SRCTREE)/cpu/mpc85xx/cpu_init_nand.c $(obj)cpu_init_nand.c
+
+$(obj)fsl_law.c:
+ @rm -f $(obj)fsl_law.c
+ ln -sf $(SRCTREE)/drivers/misc/fsl_law.c $(obj)fsl_law.c
+
+$(obj)law.c:
+ @rm -f $(obj)law.c
+ ln -sf $(SRCTREE)/board/$(BOARDDIR)/law.c $(obj)law.c
+
+$(obj)nand_boot_fsl_elbc.c:
+ @rm -f $(obj)nand_boot_fsl_elbc.c
+ ln -sf $(SRCTREE)/nand_spl/nand_boot_fsl_elbc.c \
+ $(obj)nand_boot_fsl_elbc.c
+
+$(obj)ns16550.c:
+ @rm -f $(obj)ns16550.c
+ ln -sf $(SRCTREE)/drivers/serial/ns16550.c $(obj)ns16550.c
+
+$(obj)resetvec.S:
+ @rm -f $(obj)resetvec.S
+ ln -s $(SRCTREE)/cpu/$(CPU)/resetvec.S $(obj)resetvec.S
+
+$(obj)fixed_ivor.S:
+ @rm -f $(obj)fixed_ivor.S
+ ln -sf $(SRCTREE)/cpu/mpc85xx/fixed_ivor.S $(obj)fixed_ivor.S
+
+$(obj)start.S: $(obj)fixed_ivor.S
+ @rm -f $(obj)start.S
+ ln -sf $(SRCTREE)/cpu/mpc85xx/start.S $(obj)start.S
+
+$(obj)tlb.c:
+ @rm -f $(obj)tlb.c
+ ln -sf $(SRCTREE)/cpu/mpc85xx/tlb.c $(obj)tlb.c
+
+$(obj)tlb_table.c:
+ @rm -f $(obj)tlb_table.c
+ ln -sf $(SRCTREE)/board/$(BOARDDIR)/tlb.c $(obj)tlb_table.c
+
+#########################################################################
+
+$(obj)%.o: $(obj)%.S
+ $(CC) $(AFLAGS) -c -o $@ $<
+
+$(obj)%.o: $(obj)%.c
+ $(CC) $(CFLAGS) -c -o $@ $<
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/nand_spl/board/freescale/mpc8536ds/nand_boot.c b/nand_spl/board/freescale/mpc8536ds/nand_boot.c
new file mode 100644
index 0000000..af29dc2
--- /dev/null
+++ b/nand_spl/board/freescale/mpc8536ds/nand_boot.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2009 Freescale Semiconductor, 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <ns16550.h>
+#include <asm/io.h>
+#include <nand.h>
+
+u32 sysclk_tbl[] = {
+ 33333000, 39999600, 49999500, 66666000,
+ 83332500, 99999000, 133332000, 166665000
+};
+
+void board_init_f(ulong bootflag)
+{
+ int px_spd;
+ u32 plat_ratio, bus_clk, sys_clk;
+ ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
+ ccsr_lbc_t *lbc = (void *)CONFIG_SYS_MPC85xx_LBC_ADDR;
+
+#if defined(CONFIG_SYS_BR3_PRELIM) && defined(CONFIG_SYS_OR3_PRELIM)
+ /* for FPGA */
+ out_be32(&lbc->br3, CONFIG_SYS_BR3_PRELIM);
+ out_be32(&lbc->or3, CONFIG_SYS_OR3_PRELIM);
+#else
+#error CONFIG_SYS_BR3_PRELIM, CONFIG_SYS_OR3_PRELIM must be defined
+#endif
+
+ /* initialize selected port with appropriate baud rate */
+ px_spd = in_8((unsigned char *)(PIXIS_BASE + PIXIS_SPD));
+ sys_clk = sysclk_tbl[px_spd & PIXIS_SPD_SYSCLK];
+ plat_ratio = in_be32(&gur->porpllsr) & MPC85xx_PORPLLSR_PLAT_RATIO;
+ bus_clk = sys_clk * plat_ratio / 2;
+
+ NS16550_init((NS16550_t)CONFIG_SYS_NS16550_COM1,
+ bus_clk / 16 / CONFIG_BAUDRATE);
+
+ puts("\nNAND boot... ");
+
+ /* copy code to RAM and jump to it - this should not return */
+ /* NOTE - code has to be copied out of NAND buffer before
+ * other blocks can be read.
+ */
+ relocate_code(CONFIG_SYS_NAND_U_BOOT_RELOC_SP, 0,
+ CONFIG_SYS_NAND_U_BOOT_RELOC);
+}
+
+void board_init_r(gd_t *gd, ulong dest_addr)
+{
+ nand_boot();
+}
+
+void putc(char c)
+{
+ if (c == '\n')
+ NS16550_putc((NS16550_t)CONFIG_SYS_NS16550_COM1, '\r');
+
+ NS16550_putc((NS16550_t)CONFIG_SYS_NS16550_COM1, c);
+}
+
+void puts(const char *str)
+{
+ while (*str)
+ putc(*str++);
+}