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diff --git a/doc/supplements/hppa1_1/memmodel.t b/doc/supplements/hppa1_1/memmodel.t deleted file mode 100644 index b246998e75..0000000000 --- a/doc/supplements/hppa1_1/memmodel.t +++ /dev/null @@ -1,67 +0,0 @@ -@c -@c COPYRIGHT (c) 1988-1998. -@c On-Line Applications Research Corporation (OAR). -@c All rights reserved. -@c -@c $Id$ -@c - -@chapter Memory Model - -@section Introduction - -A processor may support any combination of memory -models ranging from pure physical addressing to complex demand -paged virtual memory systems. RTEMS supports a flat memory -model which ranges contiguously over the processor's allowable -address space. RTEMS does not support segmentation or virtual -memory of any kind. The appropriate memory model for RTEMS -provided by the targeted processor and related characteristics -of that model are described in this chapter. - -@section Flat Memory Model - -RTEMS supports applications in which the application -and the executive execute within a single thirty-two bit address -space. Thus RTEMS and the application share a common four -gigabyte address space within a single space. The PA-RISC -automatically converts every address from a logical to a -physical address each time it is used. The PA-RISC uses -information provided in the page table to perform this -translation. The following protection levels are assumed: - -@itemize @bullet -@item a single code segment at protection level (0) which -contains all application and executive code. - -@item a single data segment at protection level zero (0) which -contains all application and executive data. -@end itemize - -The PA-RISC space registers and associated stack -- -including the stack pointer r27 -- must be initialized when the -initialize_executive directive is invoked. RTEMS treats the -space registers as system resources shared by all tasks and does -not modify or context switch them. - -This memory model supports a flat 32-bit address -space with addresses ranging from 0x00000000 to 0xFFFFFFFF (4 -gigabytes). Each address is represented by a 32-bit value and -memory is addressable. The address may be used to reference a -single byte, half-word (2-bytes), or word (4 bytes). - -RTEMS does not require that logical addresses map -directly to physical addresses, although it is desirable in many -applications to do so. RTEMS does not need any additional -information when physical addresses do not map directly to -physical addresses. By not requiring that logical addresses map -directly to physical addresses, the memory space of an RTEMS -space can be separated from that of a ROM monitor. For example, -a ROM monitor may load application programs into a separate -logical address space from itself. - -RTEMS assumes that the space registers contain the -selector for the single data segment when a directive is -invoked. This assumption is especially important when -developing interrupt service routines. - |