Artesyn BajaPPC-750, Руководство пользователя

Страница: 155 / 215

10-16 BajaPPC-750: Monitor
May 2002
In order for the monitor to jump to the start of the program, the first long word
of the EPROM image must contain a branch link (
bl ) instruction of the form
0100,10xx,xxxx,xxxx,xxxx,xxxx,xxxx,xx01
2
.
You can avoid jumping to an EPROM, even if a valid one is present, by changing
the nonvolatile configuration parameter “BootDev” to something other than
EPROM.
Also refer to the function BootUp in Section 10.15.2.
10.4.3 bootrom
bootrom
is an autoboot device that allows you to boot an application program
from ROM. It copies code from ROM into RAM and then jumps to the RAM
address. The ROM source address “RomBase,” the RAM destination address
“LoadAddress,” and the number of bytes to copy “RomSize” are read from the
nonvolatile memory group ‘BootParams.’
DEFINITION
void BootROM(void)
When the application is called, two parameters are passed to the application from
the nonvolatile memory group ‘BootParams.’ The parameters are seen by the
application as shown below:
Application(unsigned char Device,
unsigned char Number)
There are no arguments for this command. The nonvolatile configuration is mod-
ified with the NVRAM commands
nvdisplay and nvupdate .
Also refer to the function BootUp in Section 10.15.2.
10.4.4 bootflash
bootflash
is an autoboot device that allows you to boot an application pro-
gram from any 512k flash page. The “BankSelect” parameter in the nonvolatile
memory group ‘BootParams’ sets the Flash Bank Select Register to open the speci-
fied flash bank, which will be visible in the 512k window at address FF88,0000
16
.
If the “CopyToLoadAdr” parameter is true, the “RomSize” (number of bytes to
copy) of the application code is copied from the “RomBase” (ROM source
address) to the “LoadAddress” (RAM destination address). The application is
called at “LoadAddress.”
If the “CopyToLoadAdr” parameter is false, then the application code is called at
“RomBase.”