[U-Boot] [RFC/RFT PATCH v3 0/3] Add compressed Image booting support

[U-Boot] [RFC/RFT PATCH v3 0/3] Add compressed Image booting support

[Atish Patra]

This patch series extends booti to support compressed images
as well. Following compressed images are supported for now. 

lzma, lzo, bzip2, gz.

Other compression methods can easily be supported if required.
The above compression methods are the common ones that both
Linux kernel (ARM64/RISC-V) and U-Boot supports.

Atish Patra (3):
lib: kconfig: Add option to set BZIP2 compression method
image: Add a common compression type detection function.
image: Add compressed Image parsing support in booti.

cmd/booti.c                | 39 ++++++++++++++++++++++++++-
common/image.c             | 23 ++++++++++++++++
doc/README.distro          | 12 +++++++++
doc/board/sifive/fu540.rst | 55 ++++++++++++++++++++++++++++++++++++++
include/image.h            | 21 +++++++++++++++
lib/Kconfig                |  5 ++++
6 files changed, 154 insertions(+), 1 deletion(-)

--
2.21.0

[U-Boot] [RFC/RFT PATCH v3 1/3] lib: kconfig: Add option to set BZIP2 compression method

[Atish Patra]

There is no way to select BZIP2 compression method.
Add it under library/compression config where all other
compression related configs are present.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 lib/Kconfig | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/Kconfig b/lib/Kconfig
index 3da45a5ec322..b5dcdba23014 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -385,6 +385,11 @@ config GZIP
 	help
 	  This enables support for GZIP compression algorithm.
 
+config BZIP2
+	bool "Enable bzip2 decompression support"
+	help
+	  This enables support for BZIP2 compression algorithm.
+
 config ZLIB
 	bool
 	default y
-- 
2.21.0

[U-Boot] [RFC/RFT PATCH v3 1/3] lib: kconfig: Add option to set BZIP2 compression method

[Tom Rini]

On Wed, Nov 06, 2019 at 02:15:20PM -0800, Atish Patra wrote:

> There is no way to select BZIP2 compression method.
> Add it under library/compression config where all other
> compression related configs are present.
> 
> Signed-off-by: Atish Patra <atish.patra@wdc.com>

With the note that when applying I need to run moveconfig.py on
CONFIG_BZIP2:

Reviewed-by: Tom Rini <trini@konsulko.com>

-- 
Tom
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[U-Boot] [RFC/RFT PATCH v3 2/3] image: Add a common compression type detection function.

[Atish Patra]

Currently, there is no method that can detect compression types
given a file. This is very useful where a compressed kernel image
is loaded directly to the memory.

Inspect initial few bytes to figure out compression type of the
image. It will be used in booti method for now but can be reused
any other function in future as well.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 common/image.c  | 23 +++++++++++++++++++++++
 include/image.h | 21 +++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/common/image.c b/common/image.c
index 179eef0bd2dc..3043f0a1c2fc 100644
--- a/common/image.c
+++ b/common/image.c
@@ -196,6 +196,14 @@ struct table_info {
 	const table_entry_t *table;
 };
 
+static const struct comp_magic_map image_comp[] = {
+	{	IH_COMP_BZIP2,	"bzip2",	{0x42, 0x5a},},
+	{	IH_COMP_GZIP,	"gzip",		{0x1f, 0x8b},},
+	{	IH_COMP_LZMA,	"lzma",		{0x5d, 0x00},},
+	{	IH_COMP_LZO,	"lzo",		{0x89, 0x4c},},
+	{	IH_COMP_NONE,	"none",		{},	},
+};
+
 static const struct table_info table_info[IH_COUNT] = {
 	{ "architecture", IH_ARCH_COUNT, uimage_arch },
 	{ "compression", IH_COMP_COUNT, uimage_comp },
@@ -401,6 +409,21 @@ static void print_decomp_msg(int comp_type, int type, bool is_xip)
 		printf("   Uncompressing %s\n", name);
 }
 
+int image_decomp_type(const unsigned char *buf, ulong len)
+{
+	const struct comp_magic_map *cmagic = image_comp;
+
+	if (len < 2)
+		return -EINVAL;
+
+	for (; cmagic->comp_id > 0; cmagic++) {
+		if (!memcmp(buf, cmagic->magic, 2))
+			break;
+	}
+
+	return cmagic->comp_id;
+}
+
 int image_decomp(int comp, ulong load, ulong image_start, int type,
 		 void *load_buf, void *image_buf, ulong image_len,
 		 uint unc_len, ulong *load_end)
diff --git a/include/image.h b/include/image.h
index c1065c06f9bd..733a6a107da8 100644
--- a/include/image.h
+++ b/include/image.h
@@ -447,6 +447,15 @@ typedef struct table_entry {
 	char	*lname;		/* long (output) name to print for messages */
 } table_entry_t;
 
+/*
+ * Compression type and magic number mapping table.
+ */
+struct comp_magic_map {
+	int		comp_id;
+	const char	*name;
+	unsigned char	magic[2];
+};
+
 /*
  * get_table_entry_id() scans the translation table trying to find an
  * entry that matches the given short name. If a matching entry is
@@ -851,6 +860,18 @@ static inline int image_check_target_arch(const image_header_t *hdr)
 }
 #endif /* USE_HOSTCC */
 
+/**
+ * image_decomp_type() - Find out compression type of an image
+ *
+ * @buf:	Address in U-Boot memory where image is loaded.
+ * @len:	Length of the compressed image.
+ * @return	compression type or IH_COMP_NONE if not compressed.
+ *
+ * Note: Only following compression types are supported now.
+ * lzo, lzma, gzip, bzip2
+ */
+int image_decomp_type(const unsigned char *buf, ulong len);
+
 /**
  * image_decomp() - decompress an image
  *
-- 
2.21.0

[U-Boot] [RFC/RFT PATCH v3 2/3] image: Add a common compression type detection function.

[Tom Rini]

On Wed, Nov 06, 2019 at 02:15:21PM -0800, Atish Patra wrote:

> Currently, there is no method that can detect compression types
> given a file. This is very useful where a compressed kernel image
> is loaded directly to the memory.
> 
> Inspect initial few bytes to figure out compression type of the
> image. It will be used in booti method for now but can be reused
> any other function in future as well.
> 
> Signed-off-by: Atish Patra <atish.patra@wdc.com>

Reviewed-by: Tom Rini <trini@konsulko.com>

-- 
Tom
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[U-Boot] [RFC/RFT PATCH v3 3/3] image: Add compressed Image parsing support in booti.

[Atish Patra]

Add compressed Image parsing support so that booti can parse both
flat and compressed Image to boot Linux. Currently, it is difficult
to calculate a safe address for every board where the compressed
image can be decompressed. It is also not possible to figure out the
size of the compressed file as well. Thus, user need to set two
additional environment variables kernel_comp_addr_r and filesize to
make this work.

Following compression methods are supported for now.
lzma, lzo, bzip2, gzip.

lz4 support is not added as ARM64 kernel generates a lz4 compressed
image with legacy header which U-Boot doesn't know how to parse and
decompress.

Tested on HiFive Unleashed and Qemu for RISC-V.
Tested on Qemu for ARM64.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
I could not test this patch on any ARM64 boards due to lack of
access to any ARM64 board. If anybody can test it on ARM64, that
would be great.
---
 cmd/booti.c                | 39 ++++++++++++++++++++++++++-
 doc/README.distro          | 12 +++++++++
 doc/board/sifive/fu540.rst | 55 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 105 insertions(+), 1 deletion(-)

diff --git a/cmd/booti.c b/cmd/booti.c
index c36b0235df8c..531de507149c 100644
--- a/cmd/booti.c
+++ b/cmd/booti.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/sizes.h>
 
+DECLARE_GLOBAL_DATA_PTR;
 /*
  * Image booting support
  */
@@ -23,6 +24,11 @@ static int booti_start(cmd_tbl_t *cmdtp, int flag, int argc,
 	ulong ld;
 	ulong relocated_addr;
 	ulong image_size;
+	uint8_t *temp;
+	ulong dest;
+	ulong dest_end;
+	unsigned long comp_len;
+	int ctype;
 
 	ret = do_bootm_states(cmdtp, flag, argc, argv, BOOTM_STATE_START,
 			      images, 1);
@@ -37,6 +43,33 @@ static int booti_start(cmd_tbl_t *cmdtp, int flag, int argc,
 		debug("*  kernel: cmdline image address = 0x%08lx\n", ld);
 	}
 
+	temp = map_sysmem(ld, 0);
+	ctype = image_decomp_type(temp, 2);
+	if (ctype > 0) {
+		dest = env_get_ulong("kernel_comp_addr_r", 16, 0);
+		comp_len = env_get_ulong("filesize", 16, 0);
+		if (!dest || !comp_len) {
+			puts("kernel_comp_addr_r or filesize is not provided!\n");
+			return -EINVAL;
+		}
+		if (dest < gd->ram_base || dest > gd->ram_top) {
+			puts("kernel_comp_addr_r is outside of DRAM range!\n");
+			return -EINVAL;
+		}
+
+		debug("kernel image compression type %d size = 0x%08lx address = 0x%08lx\n",
+			ctype, comp_len, (ulong)dest);
+
+		ret = image_decomp(ctype, 0, ld, IH_TYPE_KERNEL,
+				 (void *)dest, (void *)ld, comp_len,
+				 CONFIG_SYS_BOOTM_LEN, &dest_end);
+		if (ret)
+			return ret;
+		/* dest_end contains the uncompressed Image size */
+		memmove((void *) ld, (void *)dest, dest_end);
+	}
+	unmap_sysmem((void *)ld);
+
 	ret = booti_setup(ld, &relocated_addr, &image_size, false);
 	if (ret != 0)
 		return 1;
@@ -96,10 +129,14 @@ int do_booti(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 #ifdef CONFIG_SYS_LONGHELP
 static char booti_help_text[] =
 	"[addr [initrd[:size]] [fdt]]\n"
-	"    - boot Linux 'Image' stored at 'addr'\n"
+	"    - boot Linux flat or compressed 'Image' stored at 'addr'\n"
 	"\tThe argument 'initrd' is optional and specifies the address\n"
 	"\tof an initrd in memory. The optional parameter ':size' allows\n"
 	"\tspecifying the size of a RAW initrd.\n"
+	"\tCurrently only booting from gz, bz2, lzma and lz4 compression\n"
+	"\ttypes are supported. In order to boot from any of these compressed\n"
+	"\timages, user have to set kernel_comp_addr_r and filesize enviornment\n"
+	"\tvariables beforehand.\n"
 #if defined(CONFIG_OF_LIBFDT)
 	"\tSince booting a Linux kernel requires a flat device-tree, a\n"
 	"\tthird argument providing the address of the device-tree blob\n"
diff --git a/doc/README.distro b/doc/README.distro
index ab6e6f4e74be..67b49e1e4b6a 100644
--- a/doc/README.distro
+++ b/doc/README.distro
@@ -246,6 +246,18 @@ kernel_addr_r:
 
   A size of 16MB for the kernel is likely adequate.
 
+kernel_comp_addr_r:
+  Optional. This is only required if user wants to boot Linux from a compressed
+  Image(.gz, .bz2, .lzma, .lzo) using booti command. It represents the location
+  in RAM where the compressed Image will be decompressed temporarily. Once the
+  decompression is complete, decompressed data will be moved kernel_addr_r for
+  booting.
+
+filesize:
+  Optional. This is only required if user wants to boot Linux from a compressed
+  Image using booti command. It represents the size of the compressed file. The
+  size has to at least the size of loaded image for decompression to succeed.
+
 pxefile_addr_r:
 
   Mandatory. The location in RAM where extlinux.conf will be loaded to prior
diff --git a/doc/board/sifive/fu540.rst b/doc/board/sifive/fu540.rst
index 7807f5b2c128..df2c5ad8d3e3 100644
--- a/doc/board/sifive/fu540.rst
+++ b/doc/board/sifive/fu540.rst
@@ -138,6 +138,10 @@ load uImage.
    => setenv netmask 255.255.252.0
    => setenv serverip 10.206.4.143
    => setenv gateway 10.206.4.1
+
+If you want to use a flat kernel image such as Image file
+
+.. code-block:: none
    => tftpboot ${kernel_addr_r} /sifive/fu540/Image
    ethernet at 10090000: PHY present at 0
    ethernet at 10090000: Starting autonegotiation...
@@ -177,6 +181,57 @@ load uImage.
             1.2 MiB/s
    done
    Bytes transferred = 8867100 (874d1c hex)
+
+Or if you want to use a compressed kernel image file such as Image.gz
+
+.. code-block:: none
+   => tftpboot ${kernel_addr_r} /sifive/fu540/Image.gz
+   ethernet at 10090000: PHY present at 0
+   ethernet at 10090000: Starting autonegotiation...
+   ethernet at 10090000: Autonegotiation complete
+   ethernet at 10090000: link up, 1000Mbps full-duplex (lpa: 0x3c00)
+   Using ethernet at 10090000 device
+   TFTP from server 10.206.4.143; our IP address is 10.206.7.133
+   Filename '/sifive/fu540/Image.gz'.
+   Load address: 0x84000000
+   Loading: #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            #################################################################
+            ##########################################
+            1.2 MiB/s
+   done
+   Bytes transferred = 4809458 (4962f2 hex)
+   =>setenv kernel_comp_addr_r 0x90000000
+   =>setenv filesize 0x500000
+
+By this time, correct kernel image is loaded and required enviornment variables
+are set. You can proceed to load the ramdisk and device tree from the tftp server
+as well.
+
+.. code-block:: none
    => tftpboot ${ramdisk_addr_r} /sifive/fu540/uRamdisk
    ethernet at 10090000: PHY present at 0
    ethernet at 10090000: Starting autonegotiation...
-- 
2.21.0

[U-Boot] [RFC/RFT PATCH v3 3/3] image: Add compressed Image parsing support in booti.

[Tom Rini]

On Wed, Nov 06, 2019 at 02:15:22PM -0800, Atish Patra wrote:

> Add compressed Image parsing support so that booti can parse both
> flat and compressed Image to boot Linux. Currently, it is difficult
> to calculate a safe address for every board where the compressed
> image can be decompressed. It is also not possible to figure out the
> size of the compressed file as well. Thus, user need to set two
> additional environment variables kernel_comp_addr_r and filesize to
> make this work.
> 
> Following compression methods are supported for now.
> lzma, lzo, bzip2, gzip.
> 
> lz4 support is not added as ARM64 kernel generates a lz4 compressed
> image with legacy header which U-Boot doesn't know how to parse and
> decompress.
> 
> Tested on HiFive Unleashed and Qemu for RISC-V.
> Tested on Qemu for ARM64.
> 
> Signed-off-by: Atish Patra <atish.patra@wdc.com>

Reviewed-by: Tom Rini <trini@konsulko.com>

-- 
Tom
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[U-Boot] [RFC/RFT PATCH v3 3/3] image: Add compressed Image parsing support in booti.

[Atish Patra]

On Wed, 2019-11-06 at 14:15 -0800, Atish Patra wrote:
> Add compressed Image parsing support so that booti can parse both
> flat and compressed Image to boot Linux. Currently, it is difficult
> to calculate a safe address for every board where the compressed
> image can be decompressed. It is also not possible to figure out the
> size of the compressed file as well. Thus, user need to set two
> additional environment variables kernel_comp_addr_r and filesize to
> make this work.
> 
> Following compression methods are supported for now.
> lzma, lzo, bzip2, gzip.
> 
> lz4 support is not added as ARM64 kernel generates a lz4 compressed
> image with legacy header which U-Boot doesn't know how to parse and
> decompress.
> 
> Tested on HiFive Unleashed and Qemu for RISC-V.
> Tested on Qemu for ARM64.
> 
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> ---
> I could not test this patch on any ARM64 boards due to lack of
> access to any ARM64 board. If anybody can test it on ARM64, that
> would be great.
> ---
>  cmd/booti.c                | 39 ++++++++++++++++++++++++++-
>  doc/README.distro          | 12 +++++++++
>  doc/board/sifive/fu540.rst | 55
> ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 105 insertions(+), 1 deletion(-)
> 
> diff --git a/cmd/booti.c b/cmd/booti.c
> index c36b0235df8c..531de507149c 100644
> --- a/cmd/booti.c
> +++ b/cmd/booti.c
> @@ -13,6 +13,7 @@
>  #include <linux/kernel.h>
>  #include <linux/sizes.h>
>  
> +DECLARE_GLOBAL_DATA_PTR;
>  /*
>   * Image booting support
>   */
> @@ -23,6 +24,11 @@ static int booti_start(cmd_tbl_t *cmdtp, int flag,
> int argc,
>  	ulong ld;
>  	ulong relocated_addr;
>  	ulong image_size;
> +	uint8_t *temp;
> +	ulong dest;
> +	ulong dest_end;
> +	unsigned long comp_len;
> +	int ctype;
>  
>  	ret = do_bootm_states(cmdtp, flag, argc, argv,
> BOOTM_STATE_START,
>  			      images, 1);
> @@ -37,6 +43,33 @@ static int booti_start(cmd_tbl_t *cmdtp, int flag,
> int argc,
>  		debug("*  kernel: cmdline image address = 0x%08lx\n",
> ld);
>  	}
>  
> +	temp = map_sysmem(ld, 0);
> +	ctype = image_decomp_type(temp, 2);
> +	if (ctype > 0) {
> +		dest = env_get_ulong("kernel_comp_addr_r", 16, 0);
> +		comp_len = env_get_ulong("filesize", 16, 0);
> +		if (!dest || !comp_len) {
> +			puts("kernel_comp_addr_r or filesize is not
> provided!\n");
> +			return -EINVAL;
> +		}
> +		if (dest < gd->ram_base || dest > gd->ram_top) {
> +			puts("kernel_comp_addr_r is outside of DRAM
> range!\n");
> +			return -EINVAL;
> +		}
> +
> +		debug("kernel image compression type %d size = 0x%08lx
> address = 0x%08lx\n",
> +			ctype, comp_len, (ulong)dest);
> +
> +		ret = image_decomp(ctype, 0, ld, IH_TYPE_KERNEL,
> +				 (void *)dest, (void *)ld, comp_len,
> +				 CONFIG_SYS_BOOTM_LEN, &dest_end);

There is a chance that CONFIG_SYS_BOOTM_LEN may not be defined or a
fixed size may not be sufficient. I have sent a v4 fixing this.

In stead of using a fixed expected uncompressed file size, we can
calculate uncompressed size as a factor of comp_len. As this is just a
maximum possible size, a higher value won't hurt.

I have modified the patch as below.

diff --git a/cmd/booti.c b/cmd/booti.c
index 531de507149c..cd8670a9a8db 100644
--- a/cmd/booti.c
+++ b/cmd/booti.c
@@ -28,6 +28,7 @@ static int booti_start(cmd_tbl_t *cmdtp, int flag,
int argc,
        ulong dest;
        ulong dest_end;
        unsigned long comp_len;
+       unsigned long decomp_len;
        int ctype;
 
        ret = do_bootm_states(cmdtp, flag, argc, argv,
BOOTM_STATE_START,
@@ -59,10 +60,10 @@ static int booti_start(cmd_tbl_t *cmdtp, int flag,
int argc,
 
                debug("kernel image compression type %d size = 0x%08lx
address = 0x%08lx\n",
                        ctype, comp_len, (ulong)dest);
-
+               decomp_len = comp_len * 10;
                ret = image_decomp(ctype, 0, ld, IH_TYPE_KERNEL,
                                 (void *)dest, (void *)ld, comp_len,
-                                CONFIG_SYS_BOOTM_LEN, &dest_end);
+                                decomp_len, &dest_end);

> +		if (ret)
> +			return ret;
> +		/* dest_end contains the uncompressed Image size */
> +		memmove((void *) ld, (void *)dest, dest_end);
> +	}
> +	unmap_sysmem((void *)ld);
> +
>  	ret = booti_setup(ld, &relocated_addr, &image_size, false);
>  	if (ret != 0)
>  		return 1;
> @@ -96,10 +129,14 @@ int do_booti(cmd_tbl_t *cmdtp, int flag, int
> argc, char * const argv[])
>  #ifdef CONFIG_SYS_LONGHELP
>  static char booti_help_text[] =
>  	"[addr [initrd[:size]] [fdt]]\n"
> -	"    - boot Linux 'Image' stored at 'addr'\n"
> +	"    - boot Linux flat or compressed 'Image' stored at
> 'addr'\n"
>  	"\tThe argument 'initrd' is optional and specifies the
> address\n"
>  	"\tof an initrd in memory. The optional parameter ':size'
> allows\n"
>  	"\tspecifying the size of a RAW initrd.\n"
> +	"\tCurrently only booting from gz, bz2, lzma and lz4
> compression\n"
> +	"\ttypes are supported. In order to boot from any of these
> compressed\n"
> +	"\timages, user have to set kernel_comp_addr_r and filesize
> enviornment\n"
> +	"\tvariables beforehand.\n"
>  #if defined(CONFIG_OF_LIBFDT)
>  	"\tSince booting a Linux kernel requires a flat device-tree,
> a\n"
>  	"\tthird argument providing the address of the device-tree
> blob\n"
> diff --git a/doc/README.distro b/doc/README.distro
> index ab6e6f4e74be..67b49e1e4b6a 100644
> --- a/doc/README.distro
> +++ b/doc/README.distro
> @@ -246,6 +246,18 @@ kernel_addr_r:
>  
>    A size of 16MB for the kernel is likely adequate.
>  
> +kernel_comp_addr_r:
> +  Optional. This is only required if user wants to boot Linux from a
> compressed
> +  Image(.gz, .bz2, .lzma, .lzo) using booti command. It represents
> the location
> +  in RAM where the compressed Image will be decompressed
> temporarily. Once the
> +  decompression is complete, decompressed data will be moved
> kernel_addr_r for
> +  booting.
> +
> +filesize:
> +  Optional. This is only required if user wants to boot Linux from a
> compressed
> +  Image using booti command. It represents the size of the
> compressed file. The
> +  size has to at least the size of loaded image for decompression to
> succeed.
> +
>  pxefile_addr_r:
>  
>    Mandatory. The location in RAM where extlinux.conf will be loaded
> to prior
> diff --git a/doc/board/sifive/fu540.rst b/doc/board/sifive/fu540.rst
> index 7807f5b2c128..df2c5ad8d3e3 100644
> --- a/doc/board/sifive/fu540.rst
> +++ b/doc/board/sifive/fu540.rst
> @@ -138,6 +138,10 @@ load uImage.
>     => setenv netmask 255.255.252.0
>     => setenv serverip 10.206.4.143
>     => setenv gateway 10.206.4.1
> +
> +If you want to use a flat kernel image such as Image file
> +
> +.. code-block:: none
>     => tftpboot ${kernel_addr_r} /sifive/fu540/Image
>     ethernet at 10090000: PHY present at 0
>     ethernet at 10090000: Starting autonegotiation...
> @@ -177,6 +181,57 @@ load uImage.
>              1.2 MiB/s
>     done
>     Bytes transferred = 8867100 (874d1c hex)
> +
> +Or if you want to use a compressed kernel image file such as
> Image.gz
> +
> +.. code-block:: none
> +   => tftpboot ${kernel_addr_r} /sifive/fu540/Image.gz
> +   ethernet at 10090000: PHY present at 0
> +   ethernet at 10090000: Starting autonegotiation...
> +   ethernet at 10090000: Autonegotiation complete
> +   ethernet at 10090000: link up, 1000Mbps full-duplex (lpa: 0x3c00)
> +   Using ethernet at 10090000 device
> +   TFTP from server 10.206.4.143; our IP address is 10.206.7.133
> +   Filename '/sifive/fu540/Image.gz'.
> +   Load address: 0x84000000
> +   Loading:
> #################################################################
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ########################################################
> #########
> +            ##########################################
> +            1.2 MiB/s
> +   done
> +   Bytes transferred = 4809458 (4962f2 hex)
> +   =>setenv kernel_comp_addr_r 0x90000000
> +   =>setenv filesize 0x500000
> +
> +By this time, correct kernel image is loaded and required
> enviornment variables
> +are set. You can proceed to load the ramdisk and device tree from
> the tftp server
> +as well.
> +
> +.. code-block:: none
>     => tftpboot ${ramdisk_addr_r} /sifive/fu540/uRamdisk
>     ethernet at 10090000: PHY present at 0
>     ethernet at 10090000: Starting autonegotiation...

-- 
Regards,
Atish