#pypp 0 // Iris: micro-kernel for a capability-based operating system. // mips/init.ccp: mips-specific boot code. // Copyright 2009 Bas Wijnen // // 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 . // Also declare things which only work during kernel init. #define INIT #define ARCH #include "../kernel.hh" #include #define NUM_SLOTS 4 #define NUM_CAPS 16 static void init_idle (): // initialize idle task as if it is currently running. idle.prev = NULL idle.next = NULL idle.schedule_prev = NULL idle.schedule_next = NULL idle.address_space = &idle_memory idle.refs.reset () idle.flags = Kernel::Thread::RUNNING | Kernel::Thread::PRIV // initialize idle_memory. idle_memory.prev = NULL idle_memory.next = NULL idle_memory.address_space = NULL idle_memory.refs.reset () idle_memory.pages = &idle_page idle_memory.threads = &idle idle_memory.memories = NULL idle_memory.limit = 0 idle_memory.used = 0 idle_memory.arch.directory = (unsigned **)0x80000000 // Shadow is never used for the idle task. idle_memory.arch.shadow = NULL idle_memory.arch.asid = 0 // initialize idle_page idle_page.prev = NULL idle_page.next = NULL idle_page.frame = 0x80000000 idle_page.flags = Kernel::Page::PAYING | Kernel::Page::FRAME idle_page.refs.reset () idle_page.address_space = NULL current = &idle directory = idle_memory.arch.directory static void init_cp0 (): // Disable watchpoint interrupts. cp0_set0 (CP0_WATCH_LO) // Use the interrupt vector for interrupts; clear interrupt pending flags. cp0_set (CP0_CAUSE, 1 << 23) // Disable interrupts and set interrupt vectors to normal. cp0_set0 (CP0_STATUS) // Reset exception base address. cp0_set0 (CP0_EBASE) // Use non-vectored interrupts. cp0_set0 (CP0_INT_CTL) // clear the tlb, hardwire page 0 to 0xffffffff // and soft-wire it to (0x294 << 20) + (0x290 << 10) // (for the idle task). cp0_set (CP0_WIRED, 1) cp0_set0 (CP0_PAGE_MASK) cp0_set0 (CP0_ENTRY_LO0) cp0_set0 (CP0_ENTRY_LO1) // Get number of tlb entries (is 31). unsigned num cp0_get (CP0_CONFIG1, num) num >>= 25 num &= 0x3f // Clear the tlb. for unsigned i = 1; i <= num; ++i: // with asid 0, no page faults will be triggered, so it's safe to map memory anywhere. cp0_set (CP0_ENTRY_HI, 0x2000 * i) cp0_set (CP0_INDEX, i) // write the data. __asm__ volatile ("tlbwi") // Fill the upper page in kseg3. cp0_set (CP0_ENTRY_HI, 0xffffe000) cp0_set (CP0_ENTRY_LO0, 0x1d) cp0_set (CP0_ENTRY_LO1, 0x1f) cp0_set0 (CP0_INDEX) __asm__ volatile ("tlbwi") // Fill the idle task's page in useg. Set it to non-cachable. // its directory entry is at 1fc, so it's number 7f (0fe00000). // its table entry is at 1f8, so it's number 7e (0007e000). // its address is 280 (00000280), used below for EPC. unsigned const idle_entry_hi = 0x0fe7e000 cp0_set (CP0_ENTRY_HI, idle_entry_hi) cp0_set (CP0_ENTRY_LO0, 0x16) cp0_set (CP0_ENTRY_LO1, 0x14) __asm__ volatile ("tlbwr") // Allow eret to be used to jump to the idle task. cp0_set (CP0_EPC, (idle_entry_hi & PAGE_MASK) | 0x280) // Wait with initializing the status register until the last moment, so that // exceptions in the bootup code will fill EPC and friends. static void init_threads (): kThread *previous = NULL first_scheduled = NULL first_alarm = NULL kReceiver *init_receiver = NULL for unsigned i = 0; i < NUM_THREADS; ++i: dbg_log ("Starting thread ") dbg_log_num (i, 2) dbg_log ("\n") kMemory *mem = top_memory.alloc_memory () assert (mem) kThread *thread = mem->alloc_thread (NUM_SLOTS) #ifndef NDEBUG thread->id = i #endif kPage **pages = (kPage **)mem->zalloc () Elf32_Ehdr *header = (Elf32_Ehdr *)thread_start[i] for unsigned j = 0; j < SELFMAG; ++j: if header->e_ident[j] != ELFMAG[j]: panic (i * 0x1000 + j, "invalid ELF magic") return if header->e_ident[EI_CLASS] != ELFCLASS32: panic (i * 0x1000 + EI_CLASS, "invalid ELF class") return if header->e_ident[EI_DATA] != ELFDATA2LSB: panic (i * 0x1000 + EI_DATA, "invalid ELF data") return if header->e_ident[EI_VERSION] != EV_CURRENT: panic (i * 0x1000 + EI_VERSION, "invalid ELF version") return if header->e_type != ET_EXEC: panic (i * 0x1000 + 0x10, "invalid ELF type") return if header->e_machine != EM_MIPS_RS3_LE && header->e_machine != EM_MIPS: panic (i * 0x1000 + 0x12, "invalid ELF machine") return thread->pc = header->e_entry thread->sp = 0x80000000 for unsigned section = 0; section < header->e_shnum; ++section: Elf32_Shdr *shdr = (Elf32_Shdr *)(thread_start[i] + header->e_shoff + section * header->e_shentsize) if ~shdr->sh_flags & SHF_ALLOC: continue bool readonly = !(shdr->sh_flags & SHF_WRITE) //bool executable = shdr->sh_flags & SHF_EXEC_INSTR if shdr->sh_type != SHT_NOBITS: unsigned file_offset = shdr->sh_offset >> PAGE_BITS if (file_offset + ((shdr->sh_size + PAGE_SIZE - 1) >> PAGE_BITS)) >= (PAGE_SIZE >> 2): panic (0x87446809, "initial thread too large") return for unsigned p = (shdr->sh_addr & PAGE_MASK); p < shdr->sh_addr + shdr->sh_size; p += PAGE_SIZE: unsigned section_offset = (p - (shdr->sh_addr & PAGE_MASK)) >> PAGE_BITS unsigned idx = file_offset + section_offset kPage *page = mem->get_mapping (p, &readonly) if page: if !pages[idx]: panic (0, "multiple pages mapped to one address in initial file") return if pages[idx]->frame != page->frame: panic (0, "different pages mapped to one address in intitial file") return continue if !pages[idx]: pages[idx] = mem->alloc_page () pages[idx]->frame = thread_start[i] + (idx << PAGE_BITS) pages[idx]->flags = Kernel::Page::PAYING | Kernel::Page::FRAME ++top_memory.limit mem->use () if !mem->map (pages[idx], p, readonly): panic (0x22446688, "unable to map initial page") return else: if readonly: panic (0x33399993, "unwritable bss section") return for unsigned p = (shdr->sh_addr & PAGE_MASK); p < shdr->sh_addr + shdr->sh_size; p += PAGE_SIZE: kPage *page = mem->get_mapping (p, &readonly) if !page: page = mem->alloc_page () if !page: panic (0x00220022, "out of memory") return page->frame = mem->zalloc () if !page->frame: panic (0x02220022, "out of memory"); return page->flags = Kernel::Page::PAYING | Kernel::Page::FRAME if !mem->map (page, p): panic (0x33557799, "unable to map initial bss page") return else: if readonly: panic (0x20203030, "bss section starts on read-only page") return for unsigned a = p; a < ((p + PAGE_SIZE) & PAGE_MASK); a += 4: if a >= shdr->sh_addr + shdr->sh_size: break if a < shdr->sh_addr: continue ((unsigned *)page->frame)[(a & ~PAGE_MASK) >> 2] = 0 for unsigned p = 0; p <= ((thread_start[i + 1] - thread_start[i] - 1) >> PAGE_BITS); ++p: if pages[p]: continue ++top_memory.limit top_memory.pfree (thread_start[i] + (p << PAGE_BITS)) kPage *stackpage = mem->alloc_page () stackpage->frame = mem->zalloc () stackpage->flags = Kernel::Page::PAYING | Kernel::Page::FRAME if !stackpage || !mem->map (stackpage, 0x7ffff000): panic (0x13151719, "unable to map initial stack page") return thread->slot[0].caps = mem->alloc_caps (NUM_CAPS) thread->slot[0].caps->first_slot.thread = thread thread->slot[0].caps->first_slot.index = 0 thread->arch.a[0] = NUM_SLOTS thread->arch.a[1] = NUM_CAPS kReceiver *recv = mem->alloc_receiver () recv->owner = thread thread->receivers = recv thread->slot[0].caps->set (__receiver_num, (kReceiverP)(CAPTYPE_RECEIVER | CAP_MASTER), Kernel::Num ((unsigned)recv), kCapRef (), &recv->refs) thread->slot[0].caps->set (__thread_num, (kReceiverP)(CAPTYPE_THREAD | CAP_MASTER), Kernel::Num ((unsigned)thread), kCapRef (), &thread->refs) thread->slot[0].caps->set (__memory_num, (kReceiverP)(CAPTYPE_MEMORY | CAP_MASTER), Kernel::Num ((unsigned)mem), kCapRef (), &mem->refs) thread->slot[0].caps->set (__call_num, (kReceiverP)(CAPTYPE_RECEIVER | Kernel::Receiver::CALL), Kernel::Num ((unsigned)recv), kCapRef (), &recv->refs) thread->flags = Kernel::Thread::RUNNING | Kernel::Thread::PRIV if !i: first_scheduled = thread init_receiver = recv else: thread->slot[0].caps->set (__parent_num, init_receiver, i, kCapRef (), &init_receiver->capabilities) previous->schedule_next = thread thread->schedule_prev = previous thread->schedule_next = NULL previous = thread mem->pfree ((unsigned)pages) // Initialize the kernel, finish by falling into the idle task. void init (unsigned mem): // Initialize board-specific things. board_init () must_wait = false // Initialize kernel variables to empty. unsigned count = init_memory (mem) // initialize system control coprocessor. init_cp0 () // initialize everything about the idle task. init_idle () // initialize top_memory. top_memory.prev = NULL top_memory.next = NULL top_memory.address_space = NULL top_memory.refs.reset () top_memory.pages = NULL top_memory.threads = NULL top_memory.memories = NULL top_memory.limit = count top_memory.used = 0 top_memory.arch.directory = NULL top_memory.arch.asid = 0 // Record all asids as unused. for unsigned i = 0; i < 63; ++i: asids[i] = i + 1 asids[63] = 0 // Set up initial threads. init_threads () // Unset all interrupt handlers. for unsigned i = 0; i < 32; ++i: arch_interrupt_receiver[i] = NULL // Enable timer interrupts. intc_unmask_irq (TIMER_INTERRUPT) // Say we're handling an exception. Since we're going to enter the idle task, allow access to cp0. // All interrupts enter the CPU through the interrupt controller at IP2, so enable that. cp0_set (CP0_STATUS, 0x1000ff13) // Done; return to user space (the idle task). __asm__ volatile ("eret")