Changes between Version 77 and Version 78 of WikiStart


Ignore:
Timestamp:
Jul 28, 2015, 10:52:58 AM (9 years ago)
Author:
alain
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • WikiStart

    v77 v78  
    77The GIET_VM assumes that the hardware architecture is structured as a 2D mesh of ''clusters''. There is one physical memory bank, and several processor cores per cluster. Each processor is identified by a composite index [x,y,p] where x, y are the cluster coordinates, and p is the local processor index.
    88
    9 The GIET_VM is written for the MIPS32 processor. The virtual adresses are on 32 bits and use the (unsigned int) type. The physicals addresses can have up to 40 bits, and use the (unsigned long long) type.
     9The GIET_VM is written for the MIPS32 processor. The virtual addresses are on 32 bits and use the (unsigned int) type. The physical addresses can have up to 40 bits, and use the (unsigned long long) type.
    1010
    1111The GIET_VM supports a paged virtual memory, with two types of pages BPP (Big Physical Pages: 2 Mbytes), and SPP (Small Physical Pages: 4 Kbytes). The physical memory allocation is fully static: all page tables (one page table per virtual space) are completely build and initialized in the boot phase. There is no page fault, and no swap on disk in the GIET_VM.
     
    1313The GIET_VM supports parallel multi-tasks user applications. A GIET_VM user application is similar to a POSIX process: one virtual space per application. A task is similar to a Posix thread: all tasks in a given application share the same virtual space. Any task can be allocated to any processor, but the allocation is fully static : no task migration.
    1414
    15 When there is more than one task allocated to a processor, the scheduling is pre-emptive, and uses a periodic TICK interrupt. It implements a round-robin policy between all runnable tasks.Therefore, there is one private scheduler for each processor.
     15When there is more than one task allocated to a processor, the scheduling is pre-emptive, and uses a periodic TICK interrupt. It implements a round-robin policy between all runnable tasks.There is one private scheduler for each processor.
    1616
    1717The GIET_VM supports generic architectures:  The hardware parameter values (such as the number of clusters, or the number of cores per cluster) are defined in the [source:soft/giet_vm/hard_config.h hard_config.h] file.