Bug: qemu_arm64: Cannot access the second flash bank

[Robin Randhawa]

Hi folks.

[CC'ing some hopefully relevant folks].

As of:

commit 0ba41ce1b7816c229cc19e0621148b98f990cb68
libfdt: return correct value if #size-cells property is not present

.. accesses to the second flash bank on the qemu_arm64 virtual board
appear broken.

To demonstrate, consider that the physical memory map for the 2 flash
banks is:

Bank 1: 0x0000_0000 - 0x03FC_0000
Bank 2: 0x0400_0000 - 0x7FC0_0000

Now, consider the abbreviated output of the flinfo command pre and post
the above commit:

Pre:
===

=> flinfo

Bank # 1: CFI conformant flash (32 x 16)  Size: 64 MB in 256 Sectors
  Intel Extended command set, Manufacturer ID: 0x89, Device ID: 0x0018
  Erase timeout: 16384 ms, write timeout: 3 ms
  Buffer write timeout: 3 ms, buffer size: 2048 bytes

  Sector Start Addresses:
  00000000   RO   00040000   RO   00080000   RO   000C0000        00100000
  00140000        00180000        001C0000        00200000        00240000
  .
  .
  03E80000        03EC0000        03F00000        03F40000        03F80000
  03FC0000

Bank # 2: CFI conformant flash (32 x 16)  Size: 64 MB in 256 Sectors
  Intel Extended command set, Manufacturer ID: 0x89, Device ID: 0x0018
  Erase timeout: 16384 ms, write timeout: 3 ms
  Buffer write timeout: 3 ms, buffer size: 2048 bytes

  Sector Start Addresses:
  04000000   RO   04040000        04080000        040C0000        04100000
  04140000        04180000        041C0000        04200000        04240000
  .
  .
  07E80000        07EC0000        07F00000        07F40000        07F80000
  07FC0000

Post:
====

=> flinfo

Bank # 1: CFI conformant flash (32 x 16)  Size: 64 MB in 256 Sectors
  Intel Extended command set, Manufacturer ID: 0x89, Device ID: 0x0018
  Erase timeout: 16384 ms, write timeout: 3 ms
  Buffer write timeout: 3 ms, buffer size: 2048 bytes

  Sector Start Addresses:
  00000000   RO   00040000   RO   00080000   RO   000C0000        00100000
  00140000        00180000        001C0000        00200000        00240000
  .
  .
  03E80000        03EC0000        03F00000        03F40000        03F80000
  03FC0000

Bank # 2: CFI conformant flash (32 x 16)  Size: 64 MB in 256 Sectors
  Intel Extended command set, Manufacturer ID: 0x89, Device ID: 0x0018
  Erase timeout: 16384 ms, write timeout: 3 ms
  Buffer write timeout: 3 ms, buffer size: 2048 bytes

  Sector Start Addresses:
  400000000000000        400000000040000        400000000080000        4000000000C0000        400000000100000
  400000000140000        400000000180000        4000000001C0000        400000000200000        400000000240000
  .
  .
 
400000003E80000        400000003EC0000        400000003F00000        40
0000003F40000        400000003F80000
  400000003FC0000

As a result, the second bank is unusable for environment stores
(CONFIG_ENV_ADDR is 0x4000000):

=> saveenv
Saving Environment to Flash... Error: start and/or end address not on
sector boundary
Error: start and/or end address not on sector boundary
Failed (1)

Rewinding the u-boot repo to before this commit fixes the problem.

Manually (uncleanly) reverting the commit and it's dependent commits
fixes the problem.

Here are the HEAD commits from the relevant repos that I used for the data above:

qemu: commit dd5b0f95490883cd8bc7d070db8de70d5c979cbc
u-boot: commit 6cb87cbb1475f668689f95911d1521ee6ba7f55c

Here is the qemu invocation I used:

$ dd if=/dev/zero of=./flash0-with-uboot.img bs=1M count=64 && dd if=/path/to/u-boot.bin of=./flash0-with-uboot.img conv=notrunc
$ qemu-system-aarch64 -M virt -cpu cortex-a53 -m 1024M -nographic -drive if=pflash,format=raw,index=0,file=flash0-with-uboot.img  -drive if=pflash,format=raw,index=1,file=flash1.img

I'm happy to help test any fixes if and as needed.

Cheers,
Robin