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[/] [openrisc/] [trunk/] [or1ksim/] [testsuite/] [test-code-or1k/] [uos/] [uos.c] - Rev 146
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/* uos.c. Microkernel for Or1ksim Copyright (C) 2000 Damjan Lampret Copyright (C) 2010 Embecosm Limited Contributor Damjan Lampret <lampret@opencores.org> Contributor Jeremy Bennett <jeremy.bennett@embecosm.com> This file is part of OpenRISC 1000 Architectural Simulator. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http: www.gnu.org/licenses/>. */ /* ---------------------------------------------------------------------------- This code is commented throughout for use with Doxygen. --------------------------------------------------------------------------*/ /* This file is part of test microkernel for OpenRISC 1000. */ #include "support.h" #include "spr-defs.h" #include "uos.h" #include "ipc.h" #include "int.h" /* External functions prototypes */ int tick_init(unsigned long period, void (* inf)(void)); /* Pointers to contexts used by except_or32.S routines */ unsigned long *task_context; unsigned long *kernel_context; /* TCBs for all tasks in the system */ struct tcb tasks[MAX_TASKS+1]; /* Stacks for the tasks (stacks[0] is kernel stack) */ unsigned char stacks[MAX_TASKS+1][STACK_SIZE]; /* MCBs for IPC messages */ struct mcb msgs[MAX_MSGS]; /* Pointer to linked list of free MCBs. */ struct mcb *free_mcbs; /* TID of the current user task */ tid_t curtask = 0; /* Statistics */ int kernel_sched_cnt = 0; int kernel_syscall_cnt = 0; /* Timestamp via or1ksim (CPU cycle number). */ unsigned long timestamp() { register unsigned long cycles asm("r3"); asm("l.sys 201"); return cycles; } /* Standard function for filling memory with a constant byte. */ void *memset(void *dst, int c, size_t size) { char *tmp = dst; for(;tmp && (tmp < (char *)dst + size); tmp++) *(char *)tmp = (char)c; return dst; } /* Traverse linked list of MCBs and show individual messages. */ void kernel_show_mcbs(struct mcb *mcb) { for(;mcb; mcb = mcb->next) { printf("MCB len=%u origintask=%u ", mcb->length, mcb->origin); printf("msg:%s\n", mcb->msg); } } /* Show all contexts. */ void kernel_show_contexts() { int i; tid_t t; for(t = 1; t <= MAX_TASKS; t++) { printf("\ntask TID=%d: PC=0x%x ", t, (unsigned)tasks[t].regs.pc & ~0x3); printf("SP(r1)=0x%x ", (unsigned)tasks[t].regs.sp); printf("SR[IEE]=%d\n", (unsigned)tasks[t].regs.sr & SPR_SR_IEE); printf("SR[TEE]=%d\n", (unsigned)tasks[t].regs.sr & SPR_SR_TEE); printf("SR[SM]=%d\n", (unsigned)tasks[t].regs.sr & SPR_SR_SM); for(i = 1; i < GPRS; i++) { if (i % 4 == 0) printf("\n"); printf("r%d=0x%.8x ", i, (unsigned)tasks[t].regs.gprs[i]); } printf("\n"); kernel_show_mcbs(tasks[t].waiting_msgs); } printf("\n"); } /* Simple round-robin scheduler that directly calls dispatcher. It is called by low level external interrupt exception handler or by kernel_syscall if KERNEL_SYSCALL_SCHED is defined. */ void kernel_sched() { if ((++curtask > MAX_TASKS) || !(tasks[curtask].regs.pc & ~0x3)) curtask = 1; task_context = (unsigned long *)&tasks[curtask].regs; #if KERNEL_OUTPUT printf("kernel_sched(): entry number %d, ", ++kernel_sched_cnt); printf("dispatching task TID=%d, time %u cycles", curtask, timestamp()); kernel_show_contexts(); #endif dispatch(); } /* System call uos_msgsnd. */ void uos_msgsnd(tid_t desttask, char *buf, int len) { asm("l.sys 1"); asm("l.nop"); } /* System call uos_msgrcv. */ void uos_msgrcv(tid_t origintask, char *buf, int len) { asm("l.sys 2"); asm("l.nop"); } /* Handles system call uos_msgsnd. */ void kernel_msgsnd(tid_t tid) { struct mcb *mcb; struct mcb **dstmq; struct tcb *task; task = &tasks[tid]; /* Sanity checks. */ /* Does destination task exist? */ if (!task->regs.gprs[1] || (task->regs.gprs[1] > MAX_TASKS)) { task->regs.gprs[9] = IPC_ENOTASK; return; } /* Are there any free MCBs? */ if (!free_mcbs) { task->regs.gprs[9] = IPC_EOUTOFMCBS; return; } /* Is message too big to fit into MCB's message buffer? */ if (task->regs.gprs[3] > MAX_MSGLEN) { task->regs.gprs[9] = IPC_ETOOBIG; return; } /* OK, send the message. */ /* First, allocate MCB. */ mcb = free_mcbs; free_mcbs = mcb->next; /* Second, copy message to the MCB. */ memcpy(mcb->msg, (void *)task->regs.gprs[2], task->regs.gprs[3]); mcb->origin = tid; mcb->length = task->regs.gprs[3]; mcb->next = NULL; /* Insert MCB into destination task's message queue at the end. */ dstmq = &tasks[task->regs.gprs[1]].waiting_msgs; for(;*dstmq;) dstmq = &((*dstmq)->next); *dstmq = mcb; task->regs.gprs[9] = IPC_NOERR; return; } /* Handles system call uos_msgrcv. */ void kernel_msgrcv(tid_t tid) { struct mcb *curmsg, **linkp; struct tcb *task; task = &tasks[tid]; /* Sanity checks. */ /* Does origin task exist? */ if (task->regs.gprs[1] > MAX_TASKS) { task->regs.gprs[9] = IPC_ENOTASK; return; } /* Are there any messages waiting for reception? */ if (!task->waiting_msgs) { task->regs.gprs[9] = IPC_ENOMSGS; return; } /* OK, receive the message. */ /* Search waiting messages for one coming from origintask. If origintask is zero then grab the first message. */ curmsg = task->waiting_msgs; linkp = &task->waiting_msgs; for(;task->regs.gprs[1] && curmsg->next && curmsg->origin != task->regs.gprs[1];) { linkp = &curmsg->next; curmsg = curmsg->next; } /* Is receive buffer too small for receiving message? */ if (task->regs.gprs[3] < curmsg->length) { task->regs.gprs[9] = IPC_ETOOBIG; return; } /* Now copy the message from the MCB. */ memcpy((void *)task->regs.gprs[2], curmsg->msg, task->regs.gprs[3]); /* Remove MCB from task's waiting queue and place it back into free MCBs queue. */ *linkp = curmsg->next; curmsg->next = free_mcbs; free_mcbs = curmsg; task->regs.gprs[9] = IPC_NOERR; return; } /* Handles all uOS system calls. It is called by low level system call exception handler. */ void kernel_syscall() { unsigned short syscall_num; #if KERNEL_OUTPUT printf("kernel_syscall(): entry number %d, ", ++kernel_syscall_cnt); printf("current TID=%d, time %u cycles", curtask, timestamp()); kernel_show_contexts(); #endif syscall_num = *(unsigned short *)((tasks[curtask].regs.pc & ~0x3) - 6); switch(syscall_num) { case IPC_MSGSND: kernel_msgsnd(curtask); break; case IPC_MSGRCV: kernel_msgrcv(curtask); break; default: printf("kernel_syscall(): unknown syscall (%u)\n", syscall_num); } #if KERNEL_SYSCALL_SCHED kernel_sched(); #endif dispatch(); } /* Called by reset exception handler to initialize the kernel and start rolling first task. */ void kernel_init() { tid_t t; int i; printf("Initializing kernel:\n"); printf(" Clearing kernel structures...\n"); memset(tasks, 0, sizeof(tasks)); memset(stacks, 0, sizeof(stacks)); memset(msgs, 0, sizeof(msgs)); printf(" Initializing MCBs... %d MCB(s)\n", MAX_MSGS); for(i = 0; i < (MAX_MSGS - 1); i++) msgs[i].next = &msgs[i+1]; free_mcbs = &msgs[0]; printf(" Initializing TCBs... %d user task(s)\n", MAX_TASKS); tasks_entries(); for(t = 0; t <= MAX_TASKS; t++) { tasks[t].regs.sp = (unsigned long)stacks[t] + STACK_SIZE - 4; /* Disable EXR for kernel context */ tasks[t].regs.sr |= (t == 0 ? SPR_SR_SM : SPR_SR_TEE | SPR_SR_IEE); tasks[t].regs.gprs[1] = t; } /* First task runs in seprvisor mode */ tasks[1].regs.sr |= SPR_SR_SM; /* TID=0 is reserved for kernel use */ kernel_context = (unsigned long *)&tasks[0].regs; /* First task to be scheduled is task TID=1 */ task_context = (unsigned long *)&tasks[1].regs; /* Initialize initrrupt controller */ int_init(); printf(" Exceptions will be enabled when first task is dispatched.\n"); printf("Kernel initalized. Starting first user task.\n"); #if KERNEL_SYSCALL_SCHED kernel_sched(); /* Lets schedule and dispatch our first task */ #else tick_init(TICK_PERIOD, kernel_sched); kernel_sched(); /* Lets schedule and dispatch our first task */ #endif /* ... */ /* We never get here */ } int main () { kernel_init(); return 0; }
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