ARM: shmobile: kzm9g: Declare the full 512 MiB of RAM

Quoted 27 lines · Simon Horman

Quoted 26 lines · Geert Uytterhoeven

Hi Simon, Magnus,

This patch series prepares kzm9g and kzm9g-reference dts for booting a multi-platform kernel.

Traditionally, the first 16 MiB of RAM was reserved for the RT processor. However, this is incompatible with CONFIG_AUTO_ZRELADDR=y, which requires that the start address of physical memory is a multiple of 128 MiB.

As CONFIG_AUTO_ZRELADDR=y is enabled for multi-platform kernels, declare RAM to start at 0x40000000.

While at it, reclaim the last 8 MiB of RAM, too, so the full 512 MiB is available. We don't know the exact reason why the last 8 MiB of RAM was reserved, but thanks to Simon we know it is not used for a U-Boot splash screen. Note that kzm9g_defconfig still has CONFIG_MEMORY_START=0x41000000 and CONFIG_MEMORY_SIZE=0x1f000000, so before the advent of DT we scribbled over the last 8 MiB, too.

This is an alternative solution for "[PATCH v2 01/05] ARM: shmobile:
kzm9g-reference: 0x48008000 load address"
(http://www.spinics.net/lists/linux-sh/msg38385.html), which
(a) doesn't loose 112 MiB of RAM, and
(b) doesn't force to switch from zImage to uImage.

Quoted 3 lines

Quoted 1 line

Thanks for applying!

Thanks, done.

For the record: Olof has asked for review comments for the BSC driver and binding patches. Accordingly I have dropped them, and these patches which depend on them, from next.

This dependency may be due to the way the branches are arranged, rather than actual dependencies of the code. But regardless I am dropping all effected branches for now.