Changes between Version 79 and Version 80 of WikiStart
- Timestamp:
- Oct 16, 2015, 12:53:13 PM (10 years ago)
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WikiStart
v79 v80 11 11 The 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. 12 12 13 The GIET_VM supports parallel multi-t asks 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.13 The GIET_VM supports parallel multi-threaded applications. A GIET_VM user application is similar to a POSIX process: one virtual space per application. The GIET-VM threads use the POSIX threads API. All threads in a parallel application share the same virtual space. Any thread can be mapped to any processor, but the allocation is fully static : no task migration. 14 14 15 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.There is one private scheduler for each processor. 16 16 17 Regarding peripherals, the GIET-VM provide specific system calls allowing applications to get one or several private peripheral channels (for TTY terminals, for the network controller, or for dedicated coprocessors. 18 19 Finally, the GIET-VM implements a FAT32 file system, with a distributed software cache, and provide the corresponding system calls. 20 17 21 The 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. 18 22 19 The GIET-VM configuration parameters (such as the TICK period, or the max number of open files)are defined in the [source:soft/giet_vm/giet_config.h giet_config.h] file.23 The GIET-VM defines various configuration parameters (such as the TICK period, or the max number of open files). They are defined in the [source:soft/giet_vm/giet_config.h giet_config.h] file. 20 24 21 25