/**************************************************************************** * arch/x86/src/qemu/qemu_head.S * * Copyright (C) 2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Based on Bran's kernel development tutorials. Rewritten for JamesM's * kernel development tutorials. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include .file "qemu_vectors.S" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define KSEG 0x10 /**************************************************************************** * .text ****************************************************************************/ .text /**************************************************************************** * Globals ****************************************************************************/ .globl irq_handler .globl isr_handler /**************************************************************************** * Macros ****************************************************************************/ /* Trace macros, use like trace 'i' to print char to serial port. */ .macro trace, ch mov $0x3f8, %dx mov $\ch, %al out %al, %dx .endm /* This macro creates a stub for an ISR which does NOT pass it's own * error code (adds a dummy errcode byte). */ .macro ISR_NOERRCODE, intno .globl vector_isr\intno vector_isr\intno: cli /* Disable interrupts firstly. */ push $0 /* Push a dummy error code. */ push $\intno /* Push the interrupt number. */ jmp isr_common /* Go to the common ISR handler code. */ .endm /* This macro creates a stub for an ISR which passes it's own * error code. */ .macro ISR_ERRCODE, intno .globl vector_isr\intno vector_isr\intno: cli /* Disable interrupts firstly. */ push $\intno /* Push the interrupt number. */ jmp isr_common /* Go to the common ISR handler code. */ .endm /* This macro creates a stub for an IRQ - the first parameter is * the IRQ number, the second is the ISR number it is remapped to. */ .macro IRQ, irqno, intno .globl vector_irq\irqno vector_irq\irqno: cli /* Disable interrupts firstly. */ push $0 /* Push a dummy error code. */ push $\intno /* Push the interrupt number. */ jmp irq_common /* Go to the common IRQ handler code. */ .endm /**************************************************************************** * IDT Vectors ****************************************************************************/ /* The following will be the vector addresses programmed into the IDT */ ISR_NOERRCODE ISR0 ISR_NOERRCODE ISR1 ISR_NOERRCODE ISR2 ISR_NOERRCODE ISR3 ISR_NOERRCODE ISR4 ISR_NOERRCODE ISR5 ISR_NOERRCODE ISR6 ISR_NOERRCODE ISR7 ISR_ERRCODE ISR8 ISR_NOERRCODE ISR9 ISR_ERRCODE ISR10 ISR_ERRCODE ISR11 ISR_ERRCODE ISR12 ISR_ERRCODE ISR13 ISR_ERRCODE ISR14 ISR_NOERRCODE ISR15 ISR_NOERRCODE ISR16 ISR_NOERRCODE ISR17 ISR_NOERRCODE ISR18 ISR_NOERRCODE ISR19 ISR_NOERRCODE ISR20 ISR_NOERRCODE ISR21 ISR_NOERRCODE ISR22 ISR_NOERRCODE ISR23 ISR_NOERRCODE ISR24 ISR_NOERRCODE ISR25 ISR_NOERRCODE ISR26 ISR_NOERRCODE ISR27 ISR_NOERRCODE ISR28 ISR_NOERRCODE ISR29 ISR_NOERRCODE ISR30 ISR_NOERRCODE ISR31 IRQ 0, IRQ0 IRQ 1, IRQ1 IRQ 2, IRQ2 IRQ 3, IRQ3 IRQ 4, IRQ4 IRQ 5, IRQ5 IRQ 6, IRQ6 IRQ 7, IRQ7 IRQ 8, IRQ8 IRQ 9, IRQ9 IRQ 10, IRQ10 IRQ 11, IRQ11 IRQ 12, IRQ12 IRQ 13, IRQ13 IRQ 14, IRQ14 IRQ 15, IRQ15 /**************************************************************************** * Name: isr_common * * Description: * This is the common ISR logic. It saves the processor state, sets up for * kernel mode segments, calls the C-level fault handler, and finally * restores the stack frame. * ****************************************************************************/ .type isr_common, @function isr_common: /* trace 'S' */ pusha /* Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax */ mov %ds, %ax /* Lower 16-bits of eax = ds. */ pushl %eax /* Save the data segment descriptor */ mov $KSEG, %ax /* Load the kernel data segment descriptor */ mov %ax, %ds mov %ax, %es mov %ax, %fs mov %ax, %gs /* The current value of the SP points to the beginning of the state save * structure. Save that on the stack as the input parameter to isr_handler. */ mov %esp, %eax push %eax call isr_handler jmp .Lreturn .size isr_common, . - isr_common /**************************************************************************** * Name: irq_common * * Description: * This is the common IRQ logic. It saves the processor state, sets up for * kernel mode segments, calls the C-level fault handler, and finally * restores the stack frame. * ****************************************************************************/ .type irq_common, @function irq_common: /* trace 'R' */ pusha /* Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax */ mov %ds, %ax /* Lower 16-bits of eax = ds. */ push %eax /* Save the data segment descriptor */ mov $KSEG, %ax /* Load the kernel data segment descriptor */ mov %ax, %ds mov %ax, %es mov %ax, %fs mov %ax, %gs /* The current value of the SP points to the beginning of the state save * structure. Save that on the stack as the input parameter to irq_handler. */ mov %esp, %eax push %eax call irq_handler /* The common return point for both isr_handler and irq_handler */ .Lreturn: add $4, %esp /* EAX may possibly hold a pointer to a different regiser save area on * return. Are we switching to a new context? */ cmp %eax, %esp je .Lnoswitch /* A context swith will be performed. EAX holds the address of the new * register save structure. * * Jump to up_fullcontextrestore(). We perform a call here, but that function * never returns. The address of the new register save block is the argument * to the up_fullcontextrestore(). */ push %eax call up_fullcontextrestore .Lnoswitch: pop %ebx /* Reload the original data segment descriptor */ mov %bx, %ds mov %bx, %es mov %bx, %fs mov %bx, %gs popa /* Pops edi,esi,ebp... */ add $8, %esp /* Cleans up the pushed error code and pushed ISR number */ iret /* Pops 3-5 things at once: CS, EIP, EFLAGS (and maybe SS and ESP) */ .size irq_common, . - irq_common .end