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

[Atish Patra <Atish.Patra@wdc.com>]

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