Re: [PATCH v4 4/5] rpi: Update environment to support booti and large initrd

[Christopher Obbard <obbardc@debian.org>]

Hi Simon,

On Thu, 2024-12-19 at 17:34 -0700, Simon Glass wrote:
> The existing values don't provide for decompressing an arm64 boot-
> image.
> Add those values and move things apart a bit so that a 50MB kernel
> can be
> accommodated.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>

Reviewed-by: Christopher Obbard <christopher.obbard@linaro.org>
Tested-by: Christopher Obbard <christopher.obbard@linaro.org> # CM4 1G

> ---
> 
> (no changes since v3)
> 
> Changes in v3:
> - Update the comment block with the new values, including compression
> 
>  board/raspberrypi/rpi/rpi.env | 27 ++++++++++++++++-----------
>  1 file changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/board/raspberrypi/rpi/rpi.env
> b/board/raspberrypi/rpi/rpi.env
> index 9b9fad82828..9ac9d6768ca 100644
> --- a/board/raspberrypi/rpi/rpi.env
> +++ b/board/raspberrypi/rpi/rpi.env
> @@ -48,28 +48,33 @@ dfu_alt_info+=zImage fat 0 1
>   *
>   * scriptaddr and pxefile_addr_r can be pretty much anywhere that
> doesn't
>   * conflict with something else. Reserving 1M for each of them at
> - * 0x02400000-0x02500000 and 0x02500000-0x02600000 should be plenty.
> + * 0x05400000-0x05500000 and 0x05500000-0x05600000 should be plenty.
>   *
>   * On ARM, both the DTB and any possible initrd must be loaded such
> that they
>   * fit inside the lowmem mapping in Linux. In practice, this usually
> means not
>   * more than ~700M away from the start of the kernel image but this
> number can
>   * be larger OR smaller depending on e.g. the 'vmalloc=xxxM' command
> line
>   * parameter given to the kernel. So reserving memory from low to
> high
> - * satisfies this constraint again. Reserving 1M at 0x02600000-
> 0x02700000 for
> - * the DTB leaves rest of the free RAM to the initrd starting at
> 0x02700000.
> - * Even with the smallest possible CPU-GPU memory split of the CPU
> getting
> - * only 64M, the remaining 25M starting at 0x02700000 should allow
> quite
> - * large initrds before they start colliding with U-Boot.
> + * satisfies this constraint again. Reserving 1M at 0x05600000-
> 0x05700000 for
> + * the DTB leaves rest of the free RAM to the initrd starting at
> 0x05700000.
> + * This means that the board must have at least 128MB of RAM
> available to
> + * U-Boot, more if the initrd is large.
>   *
> - * Limit bootm_size to 512MB so that all boot images stay within the
> bottom
> + * For compressed kernels, the maximum size is just under 32MB, with
> an area for
> + * decompression at 0x02000000 with space for 52MB, which is plenty
> for current
> + * kernels.
> + *
> + * limit bootm_size to 512MB so that all boot images stay within the
> bottom
>   * 512MB of memory
>   */
>  bootm_size=0x20000000
>  
>  kernel_addr_r=0x00080000
> -scriptaddr=0x02400000
> -pxefile_addr_r=0x02500000
> -fdt_addr_r=0x02600000
> -ramdisk_addr_r=0x02700000
> +kernel_comp_addr_r=0x02000000
> +kernel_comp_size=0x03400000
> +scriptaddr=0x05400000
> +pxefile_addr_r=0x05500000
> +fdt_addr_r=0x05600000
> +ramdisk_addr_r=0x05700000
>  
>  boot_targets=mmc usb pxe dhcp