MIPS: Alchemy: Save the Ethernet address before reusing PROM memory

Alchemy keeps pointers into the firmware environment and looks up ethaddr
when initializing the Ethernet devices. By that point, memory allocation
can have overwritten the environment, causing prom_getenv() to pass an
invalid pointer to strchr() and panic during boot.

On the MTX-1, the struct page layout change in 9ddb3c14afba reduces struct
page from 40 to 32 bytes and exposes this unreserved firmware memory.
Bisection and boot tests confirmed that the parent boots while the change
reproduces the panic.

Parse the Ethernet address during prom_init(), before registering RAM
with memblock, and keep the six bytes in kernel-owned init data. Return
the saved address during device initialization, preserving the existing
YAMON formats and command-line fallback without reserving a fixed
low-memory region.

Fixes: b93ddc4f9156 ("mips: Reserve memory for the kernel image resources")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

0 files changed, 0 insertions, 0 deletions