All modern desgin support stack pointer and it's also an
important information, so let's standardize this interface.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
All supported arch uses a push-down stack:
The stack grows toward lower addresses in memory. The stack pointer
register points to the lowest, valid working address (the "top" of
the stack). Items on the stack are referenced as positive(include zero)
word offsets from sp.
Which means that for stack in the [begin, begin + size):
1.The initial SP point to begin + size
2.push equals sub and then store
3.pop equals load and then add
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Squashed commit of the following:
Author: Gregory Nutt <gnutt@nuttx.org>
Update README.
configs/or1k: Should include header file file where exported functin is prototyped.
arch/or1k/src: Eliminate some warnings.
arch/or1k: Complete review
Fix some recently introduced build issues
configs/or1k/nsh: Convert to proper, compressed defconfig file.
Another README update.
Update README
configs/or1k: Updates from initial review.
Update README.
Author: Matt Thompson <matt@extent3d.com>
or1k: Added configurable CPU frequency to Kconfig. Calculate tick timer match period based on configured frequency.
OpenRISC: Enable instruction and data cache
OpenRISC: Initial support.
