Merge branch 'fix/misc' into topic/misc

9 files changed, 518 insertions, 137 deletions

diff --git a/arch/mips/boot/Makefile b/arch/mips/boot/Makefile
index 2a209d74f0b4..094bc84765a3 100644
--- a/arch/mips/boot/Makefile
+++ b/arch/mips/boot/Makefile
@@ -25,7 +25,7 @@ strip-flags	= $(addprefix --remove-section=,$(drop-sections))
 
 VMLINUX = vmlinux
 
-all: vmlinux.ecoff vmlinux.srec addinitrd
+all: vmlinux.ecoff vmlinux.srec
 
 vmlinux.ecoff: $(obj)/elf2ecoff $(VMLINUX)
 	$(obj)/elf2ecoff $(VMLINUX) vmlinux.ecoff $(E2EFLAGS)
@@ -39,11 +39,7 @@ vmlinux.bin: $(VMLINUX)
 vmlinux.srec: $(VMLINUX)
 	$(OBJCOPY) -S -O srec $(strip-flags) $(VMLINUX) $(obj)/vmlinux.srec
 
-$(obj)/addinitrd: $(obj)/addinitrd.c
-	$(HOSTCC) -o $@ $^
-
-clean-files += addinitrd \
-	       elf2ecoff \
+clean-files += elf2ecoff \
 	       vmlinux.bin \
 	       vmlinux.ecoff \
 	       vmlinux.srec
diff --git a/arch/mips/boot/addinitrd.c b/arch/mips/boot/addinitrd.c
deleted file mode 100644
index b5b3febc10cc..000000000000
--- a/arch/mips/boot/addinitrd.c
+++ /dev/null
@@ -1,131 +0,0 @@
-/*
- * addinitrd - program to add a initrd image to an ecoff kernel
- *
- * (C) 1999 Thomas Bogendoerfer
- * minor modifications, cleanup: Guido Guenther <agx@sigxcpu.org>
- * further cleanup: Maciej W. Rozycki
- */
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <netinet/in.h>
-
-#include "ecoff.h"
-
-#define MIPS_PAGE_SIZE	4096
-#define MIPS_PAGE_MASK	(MIPS_PAGE_SIZE-1)
-
-#define swab16(x) \
-        ((unsigned short)( \
-                (((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \
-                (((unsigned short)(x) & (unsigned short)0xff00U) >> 8) ))
-
-#define swab32(x) \
-        ((unsigned int)( \
-                (((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \
-                (((unsigned int)(x) & (unsigned int)0x0000ff00UL) <<  8) | \
-                (((unsigned int)(x) & (unsigned int)0x00ff0000UL) >>  8) | \
-                (((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) ))
-
-#define SWAB(a)	(swab ? swab32(a) : (a))
-
-void die(char *s)
-{
-	perror(s);
-	exit(1);
-}
-
-int main(int argc, char *argv[])
-{
-	int fd_vmlinux, fd_initrd, fd_outfile;
-	FILHDR efile;
-	AOUTHDR eaout;
-	SCNHDR esecs[3];
-	struct stat st;
-	char buf[1024];
-	unsigned long loadaddr;
-	unsigned long initrd_header[2];
-	int i, cnt;
-	int swab = 0;
-
-	if (argc != 4) {
-		printf("Usage: %s <vmlinux> <initrd> <outfile>\n", argv[0]);
-		exit(1);
-	}
-
-	if ((fd_vmlinux = open (argv[1], O_RDONLY)) < 0)
-		 die("open vmlinux");
-	if (read (fd_vmlinux, &efile, sizeof efile) != sizeof efile)
-		die("read file header");
-	if (read (fd_vmlinux, &eaout, sizeof eaout) != sizeof eaout)
-		die("read aout header");
-	if (read (fd_vmlinux, esecs, sizeof esecs) != sizeof esecs)
-		die("read section headers");
-	/*
-	 * check whether the file is good for us
-	 */
-	/* TBD */
-
-	/*
-	 * check, if we have to swab words
-	 */
-	if (ntohs(0xaa55) == 0xaa55) {
-		if (efile.f_magic == swab16(MIPSELMAGIC))
-			swab = 1;
-	} else {
-		if (efile.f_magic == swab16(MIPSEBMAGIC))
-			swab = 1;
-	}
-
-	/* make sure we have an empty data segment for the initrd */
-	if (eaout.dsize || esecs[1].s_size) {
-		fprintf(stderr, "Data segment not empty. Giving up!\n");
-		exit(1);
-	}
-	if ((fd_initrd = open (argv[2], O_RDONLY)) < 0)
-		die("open initrd");
-	if (fstat (fd_initrd, &st) < 0)
-		die("fstat initrd");
-	loadaddr = ((SWAB(esecs[2].s_vaddr) + SWAB(esecs[2].s_size)
-			+ MIPS_PAGE_SIZE-1) & ~MIPS_PAGE_MASK) - 8;
-	if (loadaddr < (SWAB(esecs[2].s_vaddr) + SWAB(esecs[2].s_size)))
-		loadaddr += MIPS_PAGE_SIZE;
-	initrd_header[0] = SWAB(0x494E5244);
-	initrd_header[1] = SWAB(st.st_size);
-	eaout.dsize = esecs[1].s_size = initrd_header[1] = SWAB(st.st_size+8);
-	eaout.data_start = esecs[1].s_vaddr = esecs[1].s_paddr = SWAB(loadaddr);
-
-	if ((fd_outfile = open (argv[3], O_RDWR|O_CREAT|O_TRUNC, 0666)) < 0)
-		die("open outfile");
-	if (write (fd_outfile, &efile, sizeof efile) != sizeof efile)
-		die("write file header");
-	if (write (fd_outfile, &eaout, sizeof eaout) != sizeof eaout)
-		die("write aout header");
-	if (write (fd_outfile, esecs, sizeof esecs) != sizeof esecs)
-		die("write section headers");
-	/* skip padding */
-	if(lseek(fd_vmlinux, SWAB(esecs[0].s_scnptr), SEEK_SET) == (off_t)-1)
-		die("lseek vmlinux");
-	if(lseek(fd_outfile, SWAB(esecs[0].s_scnptr), SEEK_SET) == (off_t)-1)
-		die("lseek outfile");
-	/* copy text segment */
-	cnt = SWAB(eaout.tsize);
-	while (cnt) {
-		if ((i = read (fd_vmlinux, buf, sizeof buf)) <= 0)
-			die("read vmlinux");
-		if (write (fd_outfile, buf, i) != i)
-			die("write vmlinux");
-		cnt -= i;
-	}
-	if (write (fd_outfile, initrd_header, sizeof initrd_header) != sizeof initrd_header)
-		die("write initrd header");
-	while ((i = read (fd_initrd, buf, sizeof buf)) > 0)
-		if (write (fd_outfile, buf, i) != i)
-			die("write initrd");
-	close(fd_vmlinux);
-	close(fd_initrd);
-	return 0;
-}
diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
new file mode 100644
index 000000000000..e27f40bbd4e5
--- /dev/null
+++ b/arch/mips/boot/compressed/Makefile
@@ -0,0 +1,100 @@
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.
+#
+# Adapted for MIPS Pete Popov, Dan Malek
+#
+# Copyright (C) 1994 by Linus Torvalds
+# Adapted for PowerPC by Gary Thomas
+# modified by Cort (cort@cs.nmt.edu)
+#
+# Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University
+# Author: Wu Zhangjin <wuzj@lemote.com>
+#
+
+# compressed kernel load addr: VMLINUZ_LOAD_ADDRESS > VMLINUX_LOAD_ADDRESS + VMLINUX_SIZE
+VMLINUX_SIZE := $(shell wc -c $(objtree)/$(KBUILD_IMAGE) 2>/dev/null | cut -d' ' -f1)
+VMLINUX_SIZE := $(shell [ -n "$(VMLINUX_SIZE)" ] && echo $$(($(VMLINUX_SIZE) + (65536 - $(VMLINUX_SIZE) % 65536))))
+VMLINUZ_LOAD_ADDRESS := 0x$(shell [ -n "$(VMLINUX_SIZE)" ] && printf %x $$(($(VMLINUX_LOAD_ADDRESS) + $(VMLINUX_SIZE))))
+
+# set the default size of the mallocing area for decompressing
+BOOT_HEAP_SIZE := 0x400000
+
+# Disable Function Tracer
+KBUILD_CFLAGS := $(shell echo $(KBUILD_CFLAGS) | sed -e "s/-pg//")
+
+KBUILD_CFLAGS := $(LINUXINCLUDE) $(KBUILD_CFLAGS) -D__KERNEL__ \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) -D"VMLINUX_LOAD_ADDRESS_ULL=$(VMLINUX_LOAD_ADDRESS)ull" \
+
+KBUILD_AFLAGS := $(LINUXINCLUDE) $(KBUILD_AFLAGS) -D__ASSEMBLY__ \
+	-DKERNEL_ENTRY=0x$(shell $(NM) $(objtree)/$(KBUILD_IMAGE) 2>/dev/null | grep " kernel_entry" | cut -f1 -d \ ) \
+	-DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE)
+
+obj-y := $(obj)/head.o $(obj)/decompress.o $(obj)/dbg.o
+
+obj-$(CONFIG_SYS_SUPPORTS_ZBOOT_UART16550) += $(obj)/uart-16550.o
+
+OBJCOPYFLAGS_vmlinux.bin := $(OBJCOPYFLAGS) -O binary -R .comment -S
+$(obj)/vmlinux.bin: $(KBUILD_IMAGE)
+	$(call if_changed,objcopy)
+
+suffix_$(CONFIG_KERNEL_GZIP)  = gz
+suffix_$(CONFIG_KERNEL_BZIP2) = bz2
+suffix_$(CONFIG_KERNEL_LZMA)  = lzma
+tool_$(CONFIG_KERNEL_GZIP)    = gzip
+tool_$(CONFIG_KERNEL_BZIP2)   = bzip2
+tool_$(CONFIG_KERNEL_LZMA)    = lzma
+$(obj)/vmlinux.$(suffix_y): $(obj)/vmlinux.bin
+	$(call if_changed,$(tool_y))
+
+$(obj)/piggy.o: $(obj)/vmlinux.$(suffix_y) $(obj)/dummy.o
+	$(Q)$(OBJCOPY) $(OBJCOPYFLAGS) \
+		--add-section=.image=$< \
+		--set-section-flags=.image=contents,alloc,load,readonly,data \
+		$(obj)/dummy.o $@
+
+LDFLAGS_vmlinuz := $(LDFLAGS) -Ttext $(VMLINUZ_LOAD_ADDRESS) -T
+vmlinuz: $(src)/ld.script $(obj-y) $(obj)/piggy.o
+	$(call if_changed,ld)
+	$(Q)$(OBJCOPY) $(OBJCOPYFLAGS) -R .comment -R .stab -R .stabstr -R .initrd -R .sysmap $@
+
+#
+# Some DECstations need all possible sections of an ECOFF executable
+#
+ifdef CONFIG_MACH_DECSTATION
+  E2EFLAGS = -a
+else
+  E2EFLAGS =
+endif
+
+# elf2ecoff can only handle 32bit image
+
+ifdef CONFIG_32BIT
+	VMLINUZ = vmlinuz
+else
+	VMLINUZ = vmlinuz.32
+endif
+
+vmlinuz.32: vmlinuz
+	$(Q)$(OBJCOPY) -O $(32bit-bfd) $(OBJCOPYFLAGS) $< $@
+
+vmlinuz.ecoff: $(obj)/../elf2ecoff $(VMLINUZ)
+	$(Q)$(obj)/../elf2ecoff $(VMLINUZ) vmlinuz.ecoff $(E2EFLAGS)
+
+$(obj)/../elf2ecoff: $(src)/../elf2ecoff.c
+	$(Q)$(HOSTCC) -o $@ $^
+
+drop-sections	= .reginfo .mdebug .comment .note .pdr .options .MIPS.options
+strip-flags	= $(addprefix --remove-section=,$(drop-sections))
+
+OBJCOPYFLAGS_vmlinuz.bin := $(OBJCOPYFLAGS) -O binary $(strip-flags)
+vmlinuz.bin: vmlinuz
+	$(call if_changed,objcopy)
+
+OBJCOPYFLAGS_vmlinuz.srec := $(OBJCOPYFLAGS) -S -O srec $(strip-flags)
+vmlinuz.srec: vmlinuz
+	$(call if_changed,objcopy)
+
+clean:
+clean-files += *.o \
+	       vmlinu*
diff --git a/arch/mips/boot/compressed/dbg.c b/arch/mips/boot/compressed/dbg.c
new file mode 100644
index 000000000000..ff4dc7a33a9f
--- /dev/null
+++ b/arch/mips/boot/compressed/dbg.c
@@ -0,0 +1,37 @@
+/*
+ * MIPS-specific debug support for pre-boot environment
+ *
+ * NOTE: putc() is board specific, if your board have a 16550 compatible uart,
+ * please select SYS_SUPPORTS_ZBOOT_UART16550 for your machine. othewise, you
+ * need to implement your own putc().
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+
+void __attribute__ ((weak)) putc(char c)
+{
+}
+
+void puts(const char *s)
+{
+	char c;
+	while ((c = *s++) != '\0') {
+		putc(c);
+		if (c == '\n')
+			putc('\r');
+	}
+}
+
+void puthex(unsigned long long val)
+{
+
+	unsigned char buf[10];
+	int i;
+	for (i = 7; i >= 0; i--) {
+		buf[i] = "0123456789ABCDEF"[val & 0x0F];
+		val >>= 4;
+	}
+	buf[8] = '\0';
+	puts(buf);
+}
diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
new file mode 100644
index 000000000000..67330c2f7318
--- /dev/null
+++ b/arch/mips/boot/compressed/decompress.c
@@ -0,0 +1,126 @@
+/*
+ * Misc. bootloader code for many machines.
+ *
+ * Copyright 2001 MontaVista Software Inc.
+ * Author: Matt Porter <mporter@mvista.com> Derived from
+ * arch/ppc/boot/prep/misc.c
+ *
+ * Copyright (C) 2009 Lemote, Inc. & Institute of Computing Technology
+ * Author: Wu Zhangjin <wuzj@lemote.com>
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#include <asm/addrspace.h>
+
+/* These two variables specify the free mem region
+ * that can be used for temporary malloc area
+ */
+unsigned long free_mem_ptr;
+unsigned long free_mem_end_ptr;
+char *zimage_start;
+
+/* The linker tells us where the image is. */
+extern unsigned char __image_begin, __image_end;
+extern unsigned char __ramdisk_begin, __ramdisk_end;
+unsigned long initrd_size;
+
+/* debug interfaces  */
+extern void puts(const char *s);
+extern void puthex(unsigned long long val);
+
+void error(char *x)
+{
+	puts("\n\n");
+	puts(x);
+	puts("\n\n -- System halted");
+
+	while (1)
+		;	/* Halt */
+}
+
+/* activate the code for pre-boot environment */
+#define STATIC static
+
+#ifdef CONFIG_KERNEL_GZIP
+void *memcpy(void *dest, const void *src, size_t n)
+{
+	int i;
+	const char *s = src;
+	char *d = dest;
+
+	for (i = 0; i < n; i++)
+		d[i] = s[i];
+	return dest;
+}
+#include "../../../../lib/decompress_inflate.c"
+#endif
+
+#ifdef CONFIG_KERNEL_BZIP2
+void *memset(void *s, int c, size_t n)
+{
+	int i;
+	char *ss = s;
+
+	for (i = 0; i < n; i++)
+		ss[i] = c;
+	return s;
+}
+#include "../../../../lib/decompress_bunzip2.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZMA
+#include "../../../../lib/decompress_unlzma.c"
+#endif
+
+void decompress_kernel(unsigned long boot_heap_start)
+{
+	int zimage_size;
+
+	/*
+	 * We link ourself to an arbitrary low address.  When we run, we
+	 * relocate outself to that address.  __image_beign points to
+	 * the part of the image where the zImage is. -- Tom
+	 */
+	zimage_start = (char *)(unsigned long)(&__image_begin);
+	zimage_size = (unsigned long)(&__image_end) -
+	    (unsigned long)(&__image_begin);
+
+	/*
+	 * The zImage and initrd will be between start and _end, so they've
+	 * already been moved once.  We're good to go now. -- Tom
+	 */
+	puts("zimage at:     ");
+	puthex((unsigned long)zimage_start);
+	puts(" ");
+	puthex((unsigned long)(zimage_size + zimage_start));
+	puts("\n");
+
+	if (initrd_size) {
+		puts("initrd at:     ");
+		puthex((unsigned long)(&__ramdisk_begin));
+		puts(" ");
+		puthex((unsigned long)(&__ramdisk_end));
+		puts("\n");
+	}
+
+	/* this area are prepared for mallocing when decompressing */
+	free_mem_ptr = boot_heap_start;
+	free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
+
+	/* Display standard Linux/MIPS boot prompt for kernel args */
+	puts("Uncompressing Linux at load address ");
+	puthex(VMLINUX_LOAD_ADDRESS_ULL);
+	puts("\n");
+	/* Decompress the kernel with according algorithm */
+	decompress(zimage_start, zimage_size, 0, 0,
+		   (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, error);
+	/* FIXME: is there a need to flush cache here? */
+	puts("Now, booting the kernel...\n");
+}
diff --git a/arch/mips/boot/compressed/dummy.c b/arch/mips/boot/compressed/dummy.c
new file mode 100644
index 000000000000..31dbf45bf99c
--- /dev/null
+++ b/arch/mips/boot/compressed/dummy.c
@@ -0,0 +1,4 @@
+int main(void)
+{
+	return 0;
+}
diff --git a/arch/mips/boot/compressed/head.S b/arch/mips/boot/compressed/head.S
new file mode 100644
index 000000000000..4e65a8420bee
--- /dev/null
+++ b/arch/mips/boot/compressed/head.S
@@ -0,0 +1,56 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994, 1995 Waldorf Electronics
+ * Written by Ralf Baechle and Andreas Busse
+ * Copyright (C) 1995 - 1999 Ralf Baechle
+ * Copyright (C) 1996 Paul M. Antoine
+ * Modified for DECStation and hence R3000 support by Paul M. Antoine
+ * Further modifications by David S. Miller and Harald Koerfgen
+ * Copyright (C) 1999 Silicon Graphics, Inc.
+ */
+
+#include <asm/asm.h>
+#include <asm/regdef.h>
+
+	.set noreorder
+	.cprestore
+	LEAF(start)
+start:
+	/* Save boot rom start args */
+	move	s0, a0
+	move	s1, a1
+	move	s2, a2
+	move	s3, a3
+
+	/* Clear BSS */
+	PTR_LA	a0, _edata
+	PTR_LA	a2, _end
+1:	sw	zero, 0(a0)
+	bne	a2, a0, 1b
+	 addiu	a0, a0, 4
+
+	PTR_LA	a0, (.heap)          /* heap address */
+	PTR_LA  sp, (.stack + 8192)  /* stack address */
+
+	PTR_LA	ra, 2f
+	PTR_LA	k0, decompress_kernel
+	jr	k0
+	 nop
+2:
+	move	a0, s0
+	move	a1, s1
+	move	a2, s2
+	move	a3, s3
+	PTR_LI	k0, KERNEL_ENTRY
+	jr	k0
+	 nop
+3:
+	b	3b
+	 nop
+	END(start)
+
+	.comm .heap,BOOT_HEAP_SIZE,4
+	.comm .stack,4096*2,4
diff --git a/arch/mips/boot/compressed/ld.script b/arch/mips/boot/compressed/ld.script
new file mode 100644
index 000000000000..29e9f4c0d5d8
--- /dev/null
+++ b/arch/mips/boot/compressed/ld.script
@@ -0,0 +1,150 @@
+OUTPUT_ARCH(mips)
+ENTRY(start)
+SECTIONS
+{
+  /* Read-only sections, merged into text segment: */
+  .init          : { *(.init)		} =0
+  .text      :
+  {
+    _ftext = . ;
+    *(.text)
+    *(.rodata)
+    *(.rodata1)
+    /* .gnu.warning sections are handled specially by elf32.em.  */
+    *(.gnu.warning)
+  } =0
+  .kstrtab : { *(.kstrtab) }
+
+  . = ALIGN(16);		/* Exception table */
+  __start___ex_table = .;
+  __ex_table : { *(__ex_table) }
+  __stop___ex_table = .;
+
+  __start___dbe_table = .;	/* Exception table for data bus errors */
+  __dbe_table : { *(__dbe_table) }
+  __stop___dbe_table = .;
+
+  __start___ksymtab = .;	/* Kernel symbol table */
+  __ksymtab : { *(__ksymtab) }
+  __stop___ksymtab = .;
+
+  _etext = .;
+
+  . = ALIGN(8192);
+  .data.init_task : { *(.data.init_task) }
+
+  /* Startup code */
+  . = ALIGN(4096);
+  __init_begin = .;
+  .text.init : { *(.text.init) }
+  .data.init : { *(.data.init) }
+  . = ALIGN(16);
+  __setup_start = .;
+  .setup.init : { *(.setup.init) }
+  __setup_end = .;
+  __initcall_start = .;
+  .initcall.init : { *(.initcall.init) }
+  __initcall_end = .;
+  . = ALIGN(4096);	/* Align double page for init_task_union */
+  __init_end = .;
+
+  . = ALIGN(4096);
+  .data.page_aligned : { *(.data.idt) }
+
+  . = ALIGN(32);
+  .data.cacheline_aligned : { *(.data.cacheline_aligned) }
+
+  .fini      : { *(.fini)    } =0
+  .reginfo : { *(.reginfo) }
+  /* Adjust the address for the data segment.  We want to adjust up to
+     the same address within the page on the next page up.  It would
+     be more correct to do this:
+       . = .;
+     The current expression does not correctly handle the case of a
+     text segment ending precisely at the end of a page; it causes the
+     data segment to skip a page.  The above expression does not have
+     this problem, but it will currently (2/95) cause BFD to allocate
+     a single segment, combining both text and data, for this case.
+     This will prevent the text segment from being shared among
+     multiple executions of the program; I think that is more
+     important than losing a page of the virtual address space (note
+     that no actual memory is lost; the page which is skipped can not
+     be referenced).  */
+  . = .;
+  .data    :
+  {
+    _fdata = . ;
+    *(.data)
+
+   /* Put the compressed image here, so bss is on the end. */
+   __image_begin = .;
+   *(.image)
+   __image_end = .;
+   /* Align the initial ramdisk image (INITRD) on page boundaries. */
+   . = ALIGN(4096);
+   __ramdisk_begin = .;
+   *(.initrd)
+   __ramdisk_end = .;
+   . = ALIGN(4096);
+
+    CONSTRUCTORS
+  }
+  .data1   : { *(.data1) }
+  _gp = . + 0x8000;
+  .lit8 : { *(.lit8) }
+  .lit4 : { *(.lit4) }
+  .ctors         : { *(.ctors)   }
+  .dtors         : { *(.dtors)   }
+  .got           : { *(.got.plt) *(.got) }
+  .dynamic       : { *(.dynamic) }
+  /* We want the small data sections together, so single-instruction offsets
+     can access them all, and initialized data all before uninitialized, so
+     we can shorten the on-disk segment size.  */
+  .sdata     : { *(.sdata) }
+  . = ALIGN(4);
+  _edata  =  .;
+  PROVIDE (edata = .);
+
+  __bss_start = .;
+  _fbss = .;
+  .sbss      : { *(.sbss) *(.scommon) }
+  .bss       :
+  {
+   *(.dynbss)
+   *(.bss)
+   *(COMMON)
+   .  = ALIGN(4);
+  _end = . ;
+  PROVIDE (end = .);
+  }
+
+  /* Sections to be discarded */
+  /DISCARD/ :
+  {
+        *(.text.exit)
+        *(.data.exit)
+        *(.exitcall.exit)
+  }
+
+  /* This is the MIPS specific mdebug section.  */
+  .mdebug : { *(.mdebug) }
+  /* These are needed for ELF backends which have not yet been
+     converted to the new style linker.  */
+  .stab 0 : { *(.stab) }
+  .stabstr 0 : { *(.stabstr) }
+  /* DWARF debug sections.
+     Symbols in the .debug DWARF section are relative to the beginning of the
+     section so we begin .debug at 0.  It's not clear yet what needs to happen
+     for the others.   */
+  .debug          0 : { *(.debug) }
+  .debug_srcinfo  0 : { *(.debug_srcinfo) }
+  .debug_aranges  0 : { *(.debug_aranges) }
+  .debug_pubnames 0 : { *(.debug_pubnames) }
+  .debug_sfnames  0 : { *(.debug_sfnames) }
+  .line           0 : { *(.line) }
+  /* These must appear regardless of  .  */
+  .gptab.sdata : { *(.gptab.data) *(.gptab.sdata) }
+  .gptab.sbss : { *(.gptab.bss) *(.gptab.sbss) }
+  .comment : { *(.comment) }
+  .note : { *(.note) }
+}
diff --git a/arch/mips/boot/compressed/uart-16550.c b/arch/mips/boot/compressed/uart-16550.c
new file mode 100644
index 000000000000..c9caaf4fbf60
--- /dev/null
+++ b/arch/mips/boot/compressed/uart-16550.c
@@ -0,0 +1,43 @@
+/*
+ * 16550 compatible uart based serial debug support for zboot
+ */
+
+#include <linux/types.h>
+#include <linux/serial_reg.h>
+#include <linux/init.h>
+
+#include <asm/addrspace.h>
+
+#if defined(CONFIG_MACH_LOONGSON) || defined(CONFIG_MIPS_MALTA)
+#define UART_BASE 0x1fd003f8
+#define PORT(offset) (CKSEG1ADDR(UART_BASE) + (offset))
+#endif
+
+#ifdef CONFIG_AR7
+#include <ar7.h>
+#define PORT(offset) (CKSEG1ADDR(AR7_REGS_UART0) + (4 * offset))
+#endif
+
+#ifndef PORT
+#error please define the serial port address for your own machine
+#endif
+
+static inline unsigned int serial_in(int offset)
+{
+	return *((char *)PORT(offset));
+}
+
+static inline void serial_out(int offset, int value)
+{
+	*((char *)PORT(offset)) = value;
+}
+
+void putc(char c)
+{
+	int timeout = 1024;
+
+	while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
+		;
+
+	serial_out(UART_TX, c);
+}