[PATCH] verdin-am62: fix FASTBOOT_BUF_ADDR and FASTBOOT_BUF_SIZE

[Hiago De Franco]

From: Hiago De Franco <hiago.franco at toradex.com>

The current value of CONFIG_FASTBOOT_BUF_ADDR is incorrect for hardware
with 512MB and 1GB of RAM. The RAM address ranges for these devices are:

- 512MB:
  - Start: 0x80000000
  - End:   0xA0000000
- 1GB:
  - Start: 0x80000000
  - End:   0xC0000000

The current buffer address makes fastboot downloads work only on
hardware with 2GB of RAM.

To fix this issue:
1. Lower CONFIG_FASTBOOT_BUF_ADDR to 0x80080000. This places the buffer
   near the beginning of RAM with a 512KB offset, as starting at exactly
   0x80000000 conflicts with the ATF load address. Following
   K3_ATF_LOAD_ADDR configuration, ATF is loaded at 0x80000000:

  config K3_ATF_LOAD_ADDR
    hex "Load address of ATF image"
    default 0x80000000 if (SOC_K3_AM625 || SOC_K3_AM62A7 || SOC_K3_AM62P5 || SOC_K3_J722S)
    default 0x70000000
    help
      The load address for the ATF image. This value is used to build the
      FIT image header that places ATF in memory where it will run.

2. Reduce the size of the download buffer to 128MB, avoiding overlaps
   with RAMDISK_ADDR_R. This is a good enough value for individual
   downloads.

Theses changes make fastboot downloads work with 512MB and 1GB devices.

Fixes: defe30a78b76 ("verdin-am62: add DFU, USB and UUU fastboot support")
Signed-off-by: Hiago De Franco <hiago.franco at toradex.com>
---
 configs/verdin-am62_a53_defconfig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/configs/verdin-am62_a53_defconfig b/configs/verdin-am62_a53_defconfig
index 49fb9790e295..6fa1a9d2c552 100644
--- a/configs/verdin-am62_a53_defconfig
+++ b/configs/verdin-am62_a53_defconfig
@@ -122,8 +122,8 @@ CONFIG_SYS_DFU_MAX_FILE_SIZE=0x800000
 CONFIG_DMA_CHANNELS=y
 CONFIG_TI_K3_NAVSS_UDMA=y
 CONFIG_USB_FUNCTION_FASTBOOT=y
-CONFIG_FASTBOOT_BUF_ADDR=0xC0000000
-CONFIG_FASTBOOT_BUF_SIZE=0x2F000000
+CONFIG_FASTBOOT_BUF_ADDR=0x80080000
+CONFIG_FASTBOOT_BUF_SIZE=0x8000000
 CONFIG_FASTBOOT_UUU_SUPPORT=y
 CONFIG_TI_SCI_PROTOCOL=y
 CONFIG_GPIO_HOG=y
-- 
2.39.5