ARMask.The ARM has six operating modes:
• User (unprivileged mode under which most tasks run)
• FIQ (entered when a high priority (fast) interrupt is raised)
• IRQ (entered when a low priority (normal) interrupt is raised)
• Supervisor (entered on reset and when a Software Interrupt instruction is
executed)
• Abort (used to handle memory access violations)
• Undef (used to handle undefined instructions)
* ARM Architecture Version 4 adds a seventh mode:
• System (privileged mode using the same registers as user mode)
I use C to implement thread operating,include initiallize,fork,yield,exit,kill. You should have driver to use this library. I choose array for ready queue,and strcut for Thread Control Block.
Simple operating Systems （簡(jiǎn)稱SOS）是一個(gè)可以運(yùn)行在X86平臺(tái)上（包括QEMU，BOCHS，VirtualBOX等模擬器上）的面向教學(xué)的微型嵌入式操作系統(tǒng)系列軟件。從SOS-1到SOS9，逐步完成了一個(gè)從無(wú)（只有顯示）到有（虛存、文件系統(tǒng)、線程、進(jìn)程）的操作系統(tǒng)創(chuàng)建過(guò)程。通過(guò)分析、運(yùn)行和修改此操作系統(tǒng)，會(huì)對(duì)操作系統(tǒng)的實(shí)際實(shí)現(xiàn)有更深入的的了解。這是第一部分 SOS-1。
