bdi
GDB
for BDI3000 (QorIQ P3/P4/P5)
User Manual
26
© Copyright 1997-2012 by ABATRON AG Switzerland
V 1.03
MMU XLAT [kb]
In order to support Linux kernel debugging when MMU is on, the BDI
translates effective (virtual) to physical addresses. This translation is done
based on the current MMU configuration (page tables). If this configuration
line is present, the BDI translates the addresses received from GDB be-
fore it accesses physical memory. The optional parameter defines the ker-
nel virtual base address (default is 0xC0000000) and is used for default
address translation. For more information see also chapter "Embedded
Linux MMU Support". Addresses entered at the Telnet are never translat-
ed. Translation can be probed with the Telnet command PHYS.
If not zero, the 12 lower bits of "kb" defines the position of the page present
bit in a page table entry. By default 0x800 is assumed for the page present
bit. The position may depend on the Linux kernel version.
A "kb" value of 0xFFFFFFFF disables the default translation.
kb
The kernel virtual base address (KERNELBASE)
Example:
MMU XLAT ;enable address translation
MMU XLAT 0xC0000800 ; page present bit is 0x800
PTBASE addr [64BIT]
This parameter defines the physical memory address where the BDI looks
for the virtual/physical address of the array with the two page table point-
ers. For more information see also chapter "Embedded Linux MMU Sup-
port". If this parameter is not defined, the BDI searches TLB0 in order to
translate a virtual address (TLB1 is always searched).
If the additional "64BIT" option is present, the BDI assume a 64-bit PTE.
addr
Physical address of the memory used to store the virtual
address of the array with the two page table pointers.
Example: PTBASE
0xf0
SIO port [baudrate]
When this line is present, a TCP/IP channel is routed to the BDI’s RS232
connector. The port parameter defines the TCP port used for this BDI to
host communication. You may choose any port except 0 and the default
Telnet port (23). On the host, open a Telnet session using this port. Now
you should see the UART output in this Telnet session. You can use the
normal Telnet connection to the BDI in parallel, they work completely in-
dependent. Also input to the UART is implemented.
port
The TCP/IP port used for the host communication.
baudrate
The BDI supports 2400 ... 115200 baud
Example:
SIO 7 9600 ;TCP port for virtual IO
MEMACCES mode [attr] There are two possible ways to access memory. Via the current core by
executing ld/st instructions or via the System Access Port (SAP).
See also Telnet chapter. The following modes are supported:
SAP
Memory access via SAP (default). The attr is a delay
sometimes necessary when accessing slow memory.
CORE
Memory access via current core. The optional attr pa-
rameter is explained in the Telnet chapter.
Example:
MEMACCES CORE ; access via core
MEMACCES SAP 100 ; access via SAP, 100us delay