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Update README

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This commit is contained in:
Gregory Nutt 2015-03-30 07:33:48 -06:00
parent 55a7065f07
commit 9057fe2051
1 changed files with 38 additions and 10 deletions
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configs/samv71-xult/README.txt
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@ -90,14 +90,14 @@ The BASIC nsh configuration is fully function (as desribed below under
6. There is a port of the SAMA5D4-EK Ethernet driver to the SAMV71-XULT.
This driver appears to be 100% functional with the following caveats:
- There is a compiler optimization problem. At -O2, there is odd
- There is a compiler optimization issue. At -O2, there is odd
behavior on pings and ARP messages. But the behavior is OK with
optimization set to -O2. This may or may not be a compiler
optimization issue (it could also be a timing issue or a need
for some additional volatile qualifiers).
- I- and D-Caches are enabled but the D-Cache must be enabled in
write-trough mode. This is to work around issues with the RX and TX
write-through mode. This is to work around issues with the RX and TX
descriptors with are 8-bytes in size. But the D-Cache cache line size
is 32-bytes. That means that you cannot reload, clean or invalidate a
descriptor without also effecting three neighboring descriptors.
@ -526,6 +526,17 @@ Selecting the GMAC peripheral
CONFIG_NSH_NOMAC=n : We will get the IP address from EEPROM
: Defaults should be okay for other options
Cache-Related Issues
--------------------
I- and D-Caches can be enabled but the D-Cache must be enabled in write-
through mode. This is to work around issues with the RX and TX descriptors
with are 8-bytes in size. But the D-Cache cache line size is 32-bytes.
That means that you cannot reload, clean or invalidate a descriptor without
also effecting three neighboring descriptors. Setting write through mode
eliminates the need for cleaning the D-Cache. If only reloading and
invalidating are done, then there is no problem.
Using the network with NSH
--------------------------
@ -792,13 +803,19 @@ Configuration sub-directories
2. Default stack sizes are large and should really be tuned to reduce
the RAM footprint:
CONFIG_ARCH_INTERRUPTSTACK=2048
CONFIG_SCHED_HPWORKSTACKSIZE=2048
CONFIG_IDLETHREAD_STACKSIZE=1024
CONFIG_USERMAIN_STACKSIZE=2048
CONFIG_PTHREAD_STACK_MIN=256
CONFIG_PTHREAD_STACK_DEFAULT=2048
... and others ...
CONFIG_POSIX_SPAWN_PROXY_STACKSIZE=1024
CONFIG_TASK_SPAWN_DEFAULT_STACKSIZE=2048
CONFIG_BUILTIN_PROXY_STACKSIZE=1024
CONFIG_NSH_TELNETD_DAEMONSTACKSIZE=2048
CONFIG_NSH_TELNETD_CLIENTSTACKSIZE=2048
3. NSH built-in applications are supported.
3. NSH built-in applications are supported. There are, however, not
enabled built-in applications.
Binary Formats:
CONFIG_BUILTIN=y : Enable support for built-in programs
@ -852,21 +869,31 @@ Configuration sub-directories
CONFIG_ARMV7M_ICACHE=y : Instruction cache is enabled
CONFIG_ARMV7M_DCACHE=y : Data cache is enabled
CONFIG_ARMV7M_DCACHE_WRITETHROUGH=y : Write through mode
CONFIG_ARCH_FPU=y : H/W floating point support is enabled
CONFIG_ARCH_DPFPU=y : 64-bit H/W floating point support is enabled
# CONFIG_ARMV7M_ITCM is not set : Support not yet in place
# CONFIG_ARMV7M_DTCM is not set : Support not yet in place
I- and D-Caches are enabled but the D-Cache must be enabled in write-
through mode. This is to work around issues with the RX and TX
descriptors with are 8-bytes in size. But the D-Cache cache line
size is 32-bytes. That means that you cannot reload, clean or
invalidate a descriptor without also effecting three neighboring
descriptors. Setting write through mode eliminates the need for
cleaning the D-Cache. If only reloading and invalidating are done,
then there is no problem.
Stack sizes are also large to simplify the bring-up and should be
tuned for better memory usages.
STATUS:
2015-03-28: I- and D-caches are currently disabled. Also -Os
optimization is not being used (-O2). If either the caches or higher
levels of optimization are enabled, then there are failures when trying
to ping the target from a host. This appears to be a timing-related
issue will probably not be easy to fix.
2015-03-29: I- and D-caches are currently enabled, but as noted
above, the D-Cache must be enabled in write-through mode. Also -Os
optimization is not being used (-O2). If the cache is enabled in
Write-Back mode or if higher levels of optimization are enabled, then
there are failures when trying to ping the target from a host.
nsh:
@ -1058,6 +1085,7 @@ Configuration sub-directories
CONFIG_ARMV7M_ICACHE=y : Instruction cache is enabled
CONFIG_ARMV7M_DCACHE=y : Data cache is enabled
CONFIG_ARMV7M_DCACHE_WRITETHROUGH=n : Write back mode
CONFIG_ARCH_FPU=y : H/W floating point support is enabled
CONFIG_ARCH_DPFPU=y : 64-bit H/W floating point support is enabled