Moved rdisk.c into kernel. Renamed startup.S to _startup.S
This commit is contained in:
Matt Jenkins
@@ -1 +0,0 @@
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startup.S
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405
sys/pic32/_startup.S
Normal file
405
sys/pic32/_startup.S
Normal file
@@ -0,0 +1,405 @@
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#
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# Startup code for Microchip PIC32 microcontrollers.
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# Using HID bootloader.
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#
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# Copyright (C) 2010 Serge Vakulenko, <serge@vak.ru>
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#
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# Permission to use, copy, modify, and distribute this software
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# and its documentation for any purpose and without fee is hereby
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# granted, provided that the above copyright notice appear in all
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# copies and that both that the copyright notice and this
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# permission notice and warranty disclaimer appear in supporting
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# documentation, and that the name of the author not be used in
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# advertising or publicity pertaining to distribution of the
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# software without specific, written prior permission.
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#
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# The author disclaim all warranties with regard to this
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# software, including all implied warranties of merchantability
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# and fitness. In no event shall the author be liable for any
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# special, indirect or consequential damages or any damages
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# whatsoever resulting from loss of use, data or profits, whether
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# in an action of contract, negligence or other tortious action,
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# arising out of or in connection with the use or performance of
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# this software.
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#
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#include "machine/io.h"
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#define UBASE 0x7f008000 /* User space base address */
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.set noreorder
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.set mips32r2
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.set nomips16
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.extern u
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.extern u_end
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.extern u0
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.extern main
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.extern exception
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#---------------------------------------
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# Reset vector: main entry point
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#
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.section .startup,"ax",@progbits
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.org 0
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.type _reset_vector_, @function
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_reset_vector_: .globl _reset_vector_
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.set noat
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move $1, $zero # Clear all regs
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move $2, $zero
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move $3, $zero
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move $4, $zero
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move $5, $zero
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move $6, $zero
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move $7, $zero
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move $8, $zero
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move $9, $zero
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move $10, $zero
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move $11, $zero
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move $12, $zero
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move $13, $zero
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move $14, $zero
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move $15, $zero
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move $16, $zero
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move $17, $zero
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move $18, $zero
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move $19, $zero
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move $20, $zero
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move $21, $zero
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move $22, $zero
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move $23, $zero
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move $24, $zero
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move $25, $zero
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move $26, $zero
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move $27, $zero
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move $28, $zero
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move $29, $zero
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move $30, $zero
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move $31, $zero
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mtlo $zero
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mthi $zero
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.set at
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la $sp, u_end - 16 # Stack at end of U area
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la $a0, main
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jalr $a0 # Jump to main()
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lui $gp, 0x8000 # Set global pointer (delay slot)
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la $k0, UBASE
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mtc0 $k0, $C0_EPC # Entry to user code.
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mfc0 $k0, $C0_STATUS
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ori $k0, $k0, ST_UM | ST_EXL | ST_IE # Set user mode and enable interrupts
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mtc0 $k0, $C0_STATUS # Put SR back
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ehb
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eret # PC <= EPC; EXL <= 0
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nop # just to be safe
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#---------------------------------------
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# Secondary entry point for RetroBSD bootloader.
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#
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.section .exception,"ax",@progbits
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_exception_base_: .globl _exception_base_
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.org 0
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.type _entry_vector_, @function
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_entry_vector_: .globl _entry_vector_
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la $k0, _reset_vector_
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jr $k0
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nop
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#---------------------------------------
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# Exception vector: handle interrupts and exceptions
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#
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.org 0x200
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.type _exception_vector_, @function
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_exception_vector_: .globl _exception_vector_
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mfc0 $k0, $C0_STATUS
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andi $k1, $k0, ST_UM # Check user mode
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beqz $k1, kernel_exception
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move $k1, $sp
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#
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# Exception in user mode: switch stack.
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#
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user_exception:
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la $sp, u_end # Stack at end of U area
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kernel_exception:
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addi $sp, -16-FRAME_WORDS*4 # Allocate space for registers
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save_regs:
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sw $k0, (16+FRAME_STATUS*4) ($sp)
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sw $k1, (16+FRAME_SP*4) ($sp)
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.set noat
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sw $1, (16+FRAME_R1*4) ($sp) # Save general registers
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sw $2, (16+FRAME_R2*4) ($sp)
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sw $3, (16+FRAME_R3*4) ($sp)
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sw $4, (16+FRAME_R4*4) ($sp)
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sw $5, (16+FRAME_R5*4) ($sp)
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sw $6, (16+FRAME_R6*4) ($sp)
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sw $7, (16+FRAME_R7*4) ($sp)
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sw $8, (16+FRAME_R8*4) ($sp)
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sw $9, (16+FRAME_R9*4) ($sp)
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sw $10, (16+FRAME_R10*4) ($sp)
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sw $11, (16+FRAME_R11*4) ($sp)
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sw $12, (16+FRAME_R12*4) ($sp)
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sw $13, (16+FRAME_R13*4) ($sp)
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sw $14, (16+FRAME_R14*4) ($sp)
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sw $15, (16+FRAME_R15*4) ($sp)
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sw $16, (16+FRAME_R16*4) ($sp)
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sw $17, (16+FRAME_R17*4) ($sp)
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sw $18, (16+FRAME_R18*4) ($sp)
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sw $19, (16+FRAME_R19*4) ($sp)
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sw $20, (16+FRAME_R20*4) ($sp)
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sw $21, (16+FRAME_R21*4) ($sp)
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sw $22, (16+FRAME_R22*4) ($sp)
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sw $23, (16+FRAME_R23*4) ($sp)
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sw $24, (16+FRAME_R24*4) ($sp)
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sw $25, (16+FRAME_R25*4) ($sp)
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# Skip $26 - K0
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# Skip $27 - K1
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sw $28, (16+FRAME_GP*4) ($sp)
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# Skip $29 - SP
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sw $30, (16+FRAME_FP*4) ($sp)
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sw $31, (16+FRAME_RA*4) ($sp)
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.set at
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mfhi $k0 # Save special registers
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sw $k0, (16+FRAME_HI*4) ($sp)
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mflo $k0
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sw $k0, (16+FRAME_LO*4) ($sp)
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mfc0 $k0, $C0_EPC
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sw $k0, (16+FRAME_PC*4) ($sp)
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move $a0, $sp
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addi $a0, 16 # Arg 0: saved regs.
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jal exception # Call C code.
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lui $gp, 0x8000 # Set global pointer (delay slot)
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#
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# Restore CPU state and return from interrupt.
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#
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restore_regs:
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lw $a0, (16+FRAME_LO*4) ($sp) # Load HI, LO registers
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mtlo $a0
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lw $a0, (16+FRAME_HI*4) ($sp)
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mthi $a0
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.set noat
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lw $1, (16+FRAME_R1*4) ($sp) # Load general registers
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lw $2, (16+FRAME_R2*4) ($sp)
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lw $3, (16+FRAME_R3*4) ($sp)
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lw $4, (16+FRAME_R4*4) ($sp)
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lw $5, (16+FRAME_R5*4) ($sp)
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lw $6, (16+FRAME_R6*4) ($sp)
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lw $7, (16+FRAME_R7*4) ($sp)
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lw $8, (16+FRAME_R8*4) ($sp)
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lw $9, (16+FRAME_R9*4) ($sp)
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lw $10, (16+FRAME_R10*4) ($sp)
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lw $11, (16+FRAME_R11*4) ($sp)
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lw $12, (16+FRAME_R12*4) ($sp)
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lw $13, (16+FRAME_R13*4) ($sp)
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lw $14, (16+FRAME_R14*4) ($sp)
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lw $15, (16+FRAME_R15*4) ($sp)
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lw $16, (16+FRAME_R16*4) ($sp)
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lw $17, (16+FRAME_R17*4) ($sp)
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lw $18, (16+FRAME_R18*4) ($sp)
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lw $19, (16+FRAME_R19*4) ($sp)
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lw $20, (16+FRAME_R20*4) ($sp)
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lw $21, (16+FRAME_R21*4) ($sp)
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lw $22, (16+FRAME_R22*4) ($sp)
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lw $23, (16+FRAME_R23*4) ($sp)
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lw $24, (16+FRAME_R24*4) ($sp)
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lw $25, (16+FRAME_R25*4) ($sp)
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# Skip $26 - K0
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# Skip $27 - K1
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lw $28, (16+FRAME_GP*4) ($sp)
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# Skip $29 - SP
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lw $30, (16+FRAME_FP*4) ($sp)
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.set at
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# Do not use k0/k1 here, as interrupts are still enabled
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lw $31, (16+FRAME_STATUS*4) ($sp) # K0 = saved status
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ori $31, ST_EXL # Set EXL
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mtc0 $31, $C0_STATUS # put SR back: disable interrupts
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ehb
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lw $k0, (16+FRAME_PC*4) ($sp) # K0 = EPC
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mtc0 $k0, $C0_EPC # put PC in EPC
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ext $k1, $31, 27, 1 # get RP bit: single-step request
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lw $31, (16+FRAME_RA*4) ($sp)
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lw $sp, (16+FRAME_SP*4) ($sp) # Restore stack
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# Return from exception
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bnez $k1, debug_request # single-step request
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ehb
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eret # PC <= EPC; EXL <= 0
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debug_request:
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sdbbp # enter debug mode
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#---------------------------------------
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# Debug exception processing.
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#
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.org 0x480
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.type _debug_vector_, @function
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_debug_vector_: .globl _debug_vector_
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mfc0 $k0, $C0_DEPC
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la $k1, debug_request
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bne $k0, $k1, single_step_done
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nop
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# single step request
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mfc0 $k0, $C0_DEBUG
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ori $k0, DB_SST # set SST bit
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mtc0 $k0, $C0_DEBUG
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mfc0 $k1, $C0_EPC
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mtc0 $k1, $C0_DEPC # DEPC <= EPC
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mfc0 $k0, $C0_STATUS
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xori $k0, ST_EXL # Clear EXL
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mtc0 $k0, $C0_STATUS
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ehb
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deret # PC <= DEPC; DM <= 0
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single_step_done:
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mtc0 $k0, $C0_EPC # EPC <= DEPC
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la $k1, _exception_vector_
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mtc0 $k1, $C0_DEPC # DEPC <= exception handler
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mfc0 $k0, $C0_DEBUG
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sw $k0, c0_debug # save Debug register
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ori $k0, DB_SST
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xori $k0, DB_SST # clear SST bit
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mtc0 $k0, $C0_DEBUG
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mfc0 $k1, $C0_STATUS
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ori $k1, ST_EXL # Set EXL
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mtc0 $k1, $C0_STATUS
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ehb
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deret # PC <= DEPC; DM <= 0
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#---------------------------------------
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# Icode is copied out to process 1 to exec /sbin/init.
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# If the exec fails, process 1 exits.
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#
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.globl icode, icodeend
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.type icode, @function
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.type icodeend, @function
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icode:
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la $a0, UBASE
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move $a1, $a0
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addi $a0, etcinit - icode
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addi $a1, argv - icode
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syscall 11 # SYS_execv
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move $a0, $v0
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syscall 1 # SYS_exit
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etcinit:
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.ascii "/sbin/init\0"
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initflags:
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.ascii "-\0" # ASCII initflags
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argv:
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.word etcinit + 6 - icode + UBASE # address of "init\0"
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.word initflags - icode + UBASE # init options
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.word 0
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icodeend: nop
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#---------------------------------------
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# int setjmp (label_t *env);
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#
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# Setjmp(env) will save the process' current register variables, stack
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# and program counter context and return a zero.
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#
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.type setjmp, @function
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setjmp: .globl setjmp
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sw $s0, (0 * 4) ($a0) # save register variables s0-s8
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sw $s1, (1 * 4) ($a0)
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sw $s2, (2 * 4) ($a0)
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sw $s3, (3 * 4) ($a0)
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sw $s4, (4 * 4) ($a0)
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sw $s5, (5 * 4) ($a0)
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sw $s6, (6 * 4) ($a0)
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sw $s7, (7 * 4) ($a0)
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sw $s8, (8 * 4) ($a0) # frame pointer
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sw $ra, (9 * 4) ($a0) # return address
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sw $gp, (10 * 4) ($a0) # global data pointer
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sw $sp, (11 * 4) ($a0) # stack pointer
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j $ra
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move $v0, $zero # return a zero for the setjmp call
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#---------------------------------------
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# void longjmp (memaddr uaddr, label_t *env);
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#
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# Longjmp(uaddr, env) will generate a "return(1)" from the last
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# call to setjmp(env) by mapping in the user structure pointed to by uaddr,
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# restoring the context saved by setjmp in env and returning a "1".
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# Note that registers are recovered statically from the env buffer.
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# Stack is not used.
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#
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# This longjmp differs from the longjmp found in the standard library -
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# it's actually closer to the resume routine of the 4.3BSD kernel.
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#
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.type longjmp, @function
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longjmp: .globl longjmp
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di # can't let anything in till we get a valid stack...
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la $v0, u # pointer to &u
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beq $v0, $a0, 2f # if uaddr == &u...
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nop # ...no need to remap U area
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|
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la $a3, u_end # pointer to &u + USIZE
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la $a0, u0 # pointer to &u0
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lw $v1, 0($v0) # u.u_procp
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sw $a0, 60($v1) # u.u_procp->p_addr = &u0
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# exchange contents of u and u0
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move $v1, $v0
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1:
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lw $t1, 0($v1)
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lw $t0, 0($a0)
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sw $t0, 0($v1)
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sw $t1, 0($a0)
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lw $t1, 4($v1)
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lw $t0, 4($a0)
|
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sw $t0, 4($v1)
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sw $t1, 4($a0)
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lw $t1, 8($v1)
|
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lw $t0, 8($a0)
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sw $t0, 8($v1)
|
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sw $t1, 8($a0)
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lw $t1, 12($v1)
|
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lw $t0, 12($a0)
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sw $t0, 12($v1)
|
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sw $t1, 12($a0)
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addiu $v1, $v1, 16
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bne $a3, $v1, 1b
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addiu $a0, $a0, 16
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|
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lw $v1, 0($v0) # u.u_procp
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sw $v0, 60($v1) # u.u_procp->p_addr = &u
|
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2:
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lw $s0, (0 * 4) ($a1) # restore register variables s0-s8
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lw $s1, (1 * 4) ($a1)
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lw $s2, (2 * 4) ($a1)
|
||||
lw $s3, (3 * 4) ($a1)
|
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lw $s4, (4 * 4) ($a1)
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lw $s5, (5 * 4) ($a1)
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lw $s6, (6 * 4) ($a1)
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lw $s7, (7 * 4) ($a1)
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lw $s8, (8 * 4) ($a1) # frame pointer
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lw $ra, (9 * 4) ($a1) # return address
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||||
lw $gp, (10 * 4) ($a1) # global data pointer
|
||||
lw $sp, (11 * 4) ($a1) # stack pointer
|
||||
|
||||
ei # release interrupts
|
||||
j $ra # transfer back to setjmp()
|
||||
li $v0, 1 # return value of 1
|
||||
@@ -1,405 +0,0 @@
|
||||
#
|
||||
# Startup code for Microchip PIC32 microcontrollers.
|
||||
# Using HID bootloader.
|
||||
#
|
||||
# Copyright (C) 2010 Serge Vakulenko, <serge@vak.ru>
|
||||
#
|
||||
# Permission to use, copy, modify, and distribute this software
|
||||
# and its documentation for any purpose and without fee is hereby
|
||||
# granted, provided that the above copyright notice appear in all
|
||||
# copies and that both that the copyright notice and this
|
||||
# permission notice and warranty disclaimer appear in supporting
|
||||
# documentation, and that the name of the author not be used in
|
||||
# advertising or publicity pertaining to distribution of the
|
||||
# software without specific, written prior permission.
|
||||
#
|
||||
# The author disclaim all warranties with regard to this
|
||||
# software, including all implied warranties of merchantability
|
||||
# and fitness. In no event shall the author be liable for any
|
||||
# special, indirect or consequential damages or any damages
|
||||
# whatsoever resulting from loss of use, data or profits, whether
|
||||
# in an action of contract, negligence or other tortious action,
|
||||
# arising out of or in connection with the use or performance of
|
||||
# this software.
|
||||
#
|
||||
#include "machine/io.h"
|
||||
|
||||
#define UBASE 0x7f008000 /* User space base address */
|
||||
|
||||
.set noreorder
|
||||
.set mips32r2
|
||||
.set nomips16
|
||||
|
||||
.extern u
|
||||
.extern u_end
|
||||
.extern u0
|
||||
.extern main
|
||||
.extern exception
|
||||
|
||||
#---------------------------------------
|
||||
# Reset vector: main entry point
|
||||
#
|
||||
.section .startup,"ax",@progbits
|
||||
.org 0
|
||||
.type _reset_vector_, @function
|
||||
_reset_vector_: .globl _reset_vector_
|
||||
|
||||
.set noat
|
||||
move $1, $zero # Clear all regs
|
||||
move $2, $zero
|
||||
move $3, $zero
|
||||
move $4, $zero
|
||||
move $5, $zero
|
||||
move $6, $zero
|
||||
move $7, $zero
|
||||
move $8, $zero
|
||||
move $9, $zero
|
||||
move $10, $zero
|
||||
move $11, $zero
|
||||
move $12, $zero
|
||||
move $13, $zero
|
||||
move $14, $zero
|
||||
move $15, $zero
|
||||
move $16, $zero
|
||||
move $17, $zero
|
||||
move $18, $zero
|
||||
move $19, $zero
|
||||
move $20, $zero
|
||||
move $21, $zero
|
||||
move $22, $zero
|
||||
move $23, $zero
|
||||
move $24, $zero
|
||||
move $25, $zero
|
||||
move $26, $zero
|
||||
move $27, $zero
|
||||
move $28, $zero
|
||||
move $29, $zero
|
||||
move $30, $zero
|
||||
move $31, $zero
|
||||
mtlo $zero
|
||||
mthi $zero
|
||||
.set at
|
||||
|
||||
la $sp, u_end - 16 # Stack at end of U area
|
||||
la $a0, main
|
||||
jalr $a0 # Jump to main()
|
||||
lui $gp, 0x8000 # Set global pointer (delay slot)
|
||||
|
||||
la $k0, UBASE
|
||||
mtc0 $k0, $C0_EPC # Entry to user code.
|
||||
|
||||
mfc0 $k0, $C0_STATUS
|
||||
ori $k0, $k0, ST_UM | ST_EXL | ST_IE # Set user mode and enable interrupts
|
||||
mtc0 $k0, $C0_STATUS # Put SR back
|
||||
ehb
|
||||
eret # PC <= EPC; EXL <= 0
|
||||
nop # just to be safe
|
||||
|
||||
|
||||
#---------------------------------------
|
||||
# Secondary entry point for RetroBSD bootloader.
|
||||
#
|
||||
.section .exception,"ax",@progbits
|
||||
_exception_base_: .globl _exception_base_
|
||||
|
||||
.org 0
|
||||
.type _entry_vector_, @function
|
||||
_entry_vector_: .globl _entry_vector_
|
||||
la $k0, _reset_vector_
|
||||
jr $k0
|
||||
nop
|
||||
|
||||
#---------------------------------------
|
||||
# Exception vector: handle interrupts and exceptions
|
||||
#
|
||||
.org 0x200
|
||||
.type _exception_vector_, @function
|
||||
_exception_vector_: .globl _exception_vector_
|
||||
|
||||
mfc0 $k0, $C0_STATUS
|
||||
andi $k1, $k0, ST_UM # Check user mode
|
||||
beqz $k1, kernel_exception
|
||||
move $k1, $sp
|
||||
|
||||
#
|
||||
# Exception in user mode: switch stack.
|
||||
#
|
||||
user_exception:
|
||||
la $sp, u_end # Stack at end of U area
|
||||
kernel_exception:
|
||||
addi $sp, -16-FRAME_WORDS*4 # Allocate space for registers
|
||||
save_regs:
|
||||
sw $k0, (16+FRAME_STATUS*4) ($sp)
|
||||
sw $k1, (16+FRAME_SP*4) ($sp)
|
||||
|
||||
.set noat
|
||||
sw $1, (16+FRAME_R1*4) ($sp) # Save general registers
|
||||
sw $2, (16+FRAME_R2*4) ($sp)
|
||||
sw $3, (16+FRAME_R3*4) ($sp)
|
||||
sw $4, (16+FRAME_R4*4) ($sp)
|
||||
sw $5, (16+FRAME_R5*4) ($sp)
|
||||
sw $6, (16+FRAME_R6*4) ($sp)
|
||||
sw $7, (16+FRAME_R7*4) ($sp)
|
||||
sw $8, (16+FRAME_R8*4) ($sp)
|
||||
sw $9, (16+FRAME_R9*4) ($sp)
|
||||
sw $10, (16+FRAME_R10*4) ($sp)
|
||||
sw $11, (16+FRAME_R11*4) ($sp)
|
||||
sw $12, (16+FRAME_R12*4) ($sp)
|
||||
sw $13, (16+FRAME_R13*4) ($sp)
|
||||
sw $14, (16+FRAME_R14*4) ($sp)
|
||||
sw $15, (16+FRAME_R15*4) ($sp)
|
||||
sw $16, (16+FRAME_R16*4) ($sp)
|
||||
sw $17, (16+FRAME_R17*4) ($sp)
|
||||
sw $18, (16+FRAME_R18*4) ($sp)
|
||||
sw $19, (16+FRAME_R19*4) ($sp)
|
||||
sw $20, (16+FRAME_R20*4) ($sp)
|
||||
sw $21, (16+FRAME_R21*4) ($sp)
|
||||
sw $22, (16+FRAME_R22*4) ($sp)
|
||||
sw $23, (16+FRAME_R23*4) ($sp)
|
||||
sw $24, (16+FRAME_R24*4) ($sp)
|
||||
sw $25, (16+FRAME_R25*4) ($sp)
|
||||
# Skip $26 - K0
|
||||
# Skip $27 - K1
|
||||
sw $28, (16+FRAME_GP*4) ($sp)
|
||||
# Skip $29 - SP
|
||||
sw $30, (16+FRAME_FP*4) ($sp)
|
||||
sw $31, (16+FRAME_RA*4) ($sp)
|
||||
.set at
|
||||
|
||||
mfhi $k0 # Save special registers
|
||||
sw $k0, (16+FRAME_HI*4) ($sp)
|
||||
|
||||
mflo $k0
|
||||
sw $k0, (16+FRAME_LO*4) ($sp)
|
||||
|
||||
mfc0 $k0, $C0_EPC
|
||||
sw $k0, (16+FRAME_PC*4) ($sp)
|
||||
|
||||
move $a0, $sp
|
||||
addi $a0, 16 # Arg 0: saved regs.
|
||||
jal exception # Call C code.
|
||||
lui $gp, 0x8000 # Set global pointer (delay slot)
|
||||
|
||||
#
|
||||
# Restore CPU state and return from interrupt.
|
||||
#
|
||||
restore_regs:
|
||||
lw $a0, (16+FRAME_LO*4) ($sp) # Load HI, LO registers
|
||||
mtlo $a0
|
||||
lw $a0, (16+FRAME_HI*4) ($sp)
|
||||
mthi $a0
|
||||
|
||||
.set noat
|
||||
lw $1, (16+FRAME_R1*4) ($sp) # Load general registers
|
||||
lw $2, (16+FRAME_R2*4) ($sp)
|
||||
lw $3, (16+FRAME_R3*4) ($sp)
|
||||
lw $4, (16+FRAME_R4*4) ($sp)
|
||||
lw $5, (16+FRAME_R5*4) ($sp)
|
||||
lw $6, (16+FRAME_R6*4) ($sp)
|
||||
lw $7, (16+FRAME_R7*4) ($sp)
|
||||
lw $8, (16+FRAME_R8*4) ($sp)
|
||||
lw $9, (16+FRAME_R9*4) ($sp)
|
||||
lw $10, (16+FRAME_R10*4) ($sp)
|
||||
lw $11, (16+FRAME_R11*4) ($sp)
|
||||
lw $12, (16+FRAME_R12*4) ($sp)
|
||||
lw $13, (16+FRAME_R13*4) ($sp)
|
||||
lw $14, (16+FRAME_R14*4) ($sp)
|
||||
lw $15, (16+FRAME_R15*4) ($sp)
|
||||
lw $16, (16+FRAME_R16*4) ($sp)
|
||||
lw $17, (16+FRAME_R17*4) ($sp)
|
||||
lw $18, (16+FRAME_R18*4) ($sp)
|
||||
lw $19, (16+FRAME_R19*4) ($sp)
|
||||
lw $20, (16+FRAME_R20*4) ($sp)
|
||||
lw $21, (16+FRAME_R21*4) ($sp)
|
||||
lw $22, (16+FRAME_R22*4) ($sp)
|
||||
lw $23, (16+FRAME_R23*4) ($sp)
|
||||
lw $24, (16+FRAME_R24*4) ($sp)
|
||||
lw $25, (16+FRAME_R25*4) ($sp)
|
||||
# Skip $26 - K0
|
||||
# Skip $27 - K1
|
||||
lw $28, (16+FRAME_GP*4) ($sp)
|
||||
# Skip $29 - SP
|
||||
lw $30, (16+FRAME_FP*4) ($sp)
|
||||
.set at
|
||||
|
||||
# Do not use k0/k1 here, as interrupts are still enabled
|
||||
lw $31, (16+FRAME_STATUS*4) ($sp) # K0 = saved status
|
||||
ori $31, ST_EXL # Set EXL
|
||||
mtc0 $31, $C0_STATUS # put SR back: disable interrupts
|
||||
ehb
|
||||
|
||||
lw $k0, (16+FRAME_PC*4) ($sp) # K0 = EPC
|
||||
mtc0 $k0, $C0_EPC # put PC in EPC
|
||||
ext $k1, $31, 27, 1 # get RP bit: single-step request
|
||||
|
||||
lw $31, (16+FRAME_RA*4) ($sp)
|
||||
lw $sp, (16+FRAME_SP*4) ($sp) # Restore stack
|
||||
|
||||
# Return from exception
|
||||
bnez $k1, debug_request # single-step request
|
||||
ehb
|
||||
eret # PC <= EPC; EXL <= 0
|
||||
debug_request:
|
||||
sdbbp # enter debug mode
|
||||
|
||||
#---------------------------------------
|
||||
# Debug exception processing.
|
||||
#
|
||||
.org 0x480
|
||||
.type _debug_vector_, @function
|
||||
_debug_vector_: .globl _debug_vector_
|
||||
|
||||
mfc0 $k0, $C0_DEPC
|
||||
la $k1, debug_request
|
||||
bne $k0, $k1, single_step_done
|
||||
nop
|
||||
|
||||
# single step request
|
||||
mfc0 $k0, $C0_DEBUG
|
||||
ori $k0, DB_SST # set SST bit
|
||||
mtc0 $k0, $C0_DEBUG
|
||||
|
||||
mfc0 $k1, $C0_EPC
|
||||
mtc0 $k1, $C0_DEPC # DEPC <= EPC
|
||||
mfc0 $k0, $C0_STATUS
|
||||
xori $k0, ST_EXL # Clear EXL
|
||||
mtc0 $k0, $C0_STATUS
|
||||
ehb
|
||||
deret # PC <= DEPC; DM <= 0
|
||||
|
||||
single_step_done:
|
||||
mtc0 $k0, $C0_EPC # EPC <= DEPC
|
||||
|
||||
la $k1, _exception_vector_
|
||||
mtc0 $k1, $C0_DEPC # DEPC <= exception handler
|
||||
|
||||
mfc0 $k0, $C0_DEBUG
|
||||
sw $k0, c0_debug # save Debug register
|
||||
ori $k0, DB_SST
|
||||
xori $k0, DB_SST # clear SST bit
|
||||
mtc0 $k0, $C0_DEBUG
|
||||
|
||||
mfc0 $k1, $C0_STATUS
|
||||
ori $k1, ST_EXL # Set EXL
|
||||
mtc0 $k1, $C0_STATUS
|
||||
ehb
|
||||
deret # PC <= DEPC; DM <= 0
|
||||
|
||||
#---------------------------------------
|
||||
# Icode is copied out to process 1 to exec /sbin/init.
|
||||
# If the exec fails, process 1 exits.
|
||||
#
|
||||
.globl icode, icodeend
|
||||
.type icode, @function
|
||||
.type icodeend, @function
|
||||
icode:
|
||||
la $a0, UBASE
|
||||
move $a1, $a0
|
||||
addi $a0, etcinit - icode
|
||||
addi $a1, argv - icode
|
||||
syscall 11 # SYS_execv
|
||||
move $a0, $v0
|
||||
syscall 1 # SYS_exit
|
||||
etcinit:
|
||||
.ascii "/sbin/init\0"
|
||||
initflags:
|
||||
.ascii "-\0" # ASCII initflags
|
||||
argv:
|
||||
.word etcinit + 6 - icode + UBASE # address of "init\0"
|
||||
.word initflags - icode + UBASE # init options
|
||||
.word 0
|
||||
|
||||
icodeend: nop
|
||||
|
||||
#---------------------------------------
|
||||
# int setjmp (label_t *env);
|
||||
#
|
||||
# Setjmp(env) will save the process' current register variables, stack
|
||||
# and program counter context and return a zero.
|
||||
#
|
||||
.type setjmp, @function
|
||||
setjmp: .globl setjmp
|
||||
sw $s0, (0 * 4) ($a0) # save register variables s0-s8
|
||||
sw $s1, (1 * 4) ($a0)
|
||||
sw $s2, (2 * 4) ($a0)
|
||||
sw $s3, (3 * 4) ($a0)
|
||||
sw $s4, (4 * 4) ($a0)
|
||||
sw $s5, (5 * 4) ($a0)
|
||||
sw $s6, (6 * 4) ($a0)
|
||||
sw $s7, (7 * 4) ($a0)
|
||||
sw $s8, (8 * 4) ($a0) # frame pointer
|
||||
sw $ra, (9 * 4) ($a0) # return address
|
||||
sw $gp, (10 * 4) ($a0) # global data pointer
|
||||
sw $sp, (11 * 4) ($a0) # stack pointer
|
||||
j $ra
|
||||
move $v0, $zero # return a zero for the setjmp call
|
||||
|
||||
#---------------------------------------
|
||||
# void longjmp (memaddr uaddr, label_t *env);
|
||||
#
|
||||
# Longjmp(uaddr, env) will generate a "return(1)" from the last
|
||||
# call to setjmp(env) by mapping in the user structure pointed to by uaddr,
|
||||
# restoring the context saved by setjmp in env and returning a "1".
|
||||
# Note that registers are recovered statically from the env buffer.
|
||||
# Stack is not used.
|
||||
#
|
||||
# This longjmp differs from the longjmp found in the standard library -
|
||||
# it's actually closer to the resume routine of the 4.3BSD kernel.
|
||||
#
|
||||
.type longjmp, @function
|
||||
longjmp: .globl longjmp
|
||||
|
||||
di # can't let anything in till we get a valid stack...
|
||||
|
||||
la $v0, u # pointer to &u
|
||||
beq $v0, $a0, 2f # if uaddr == &u...
|
||||
nop # ...no need to remap U area
|
||||
|
||||
la $a3, u_end # pointer to &u + USIZE
|
||||
la $a0, u0 # pointer to &u0
|
||||
|
||||
lw $v1, 0($v0) # u.u_procp
|
||||
sw $a0, 60($v1) # u.u_procp->p_addr = &u0
|
||||
|
||||
# exchange contents of u and u0
|
||||
move $v1, $v0
|
||||
1:
|
||||
lw $t1, 0($v1)
|
||||
lw $t0, 0($a0)
|
||||
sw $t0, 0($v1)
|
||||
sw $t1, 0($a0)
|
||||
lw $t1, 4($v1)
|
||||
lw $t0, 4($a0)
|
||||
sw $t0, 4($v1)
|
||||
sw $t1, 4($a0)
|
||||
lw $t1, 8($v1)
|
||||
lw $t0, 8($a0)
|
||||
sw $t0, 8($v1)
|
||||
sw $t1, 8($a0)
|
||||
lw $t1, 12($v1)
|
||||
lw $t0, 12($a0)
|
||||
sw $t0, 12($v1)
|
||||
sw $t1, 12($a0)
|
||||
addiu $v1, $v1, 16
|
||||
bne $a3, $v1, 1b
|
||||
addiu $a0, $a0, 16
|
||||
|
||||
lw $v1, 0($v0) # u.u_procp
|
||||
sw $v0, 60($v1) # u.u_procp->p_addr = &u
|
||||
2:
|
||||
lw $s0, (0 * 4) ($a1) # restore register variables s0-s8
|
||||
lw $s1, (1 * 4) ($a1)
|
||||
lw $s2, (2 * 4) ($a1)
|
||||
lw $s3, (3 * 4) ($a1)
|
||||
lw $s4, (4 * 4) ($a1)
|
||||
lw $s5, (5 * 4) ($a1)
|
||||
lw $s6, (6 * 4) ($a1)
|
||||
lw $s7, (7 * 4) ($a1)
|
||||
lw $s8, (8 * 4) ($a1) # frame pointer
|
||||
lw $ra, (9 * 4) ($a1) # return address
|
||||
lw $gp, (10 * 4) ($a1) # global data pointer
|
||||
lw $sp, (11 * 4) ($a1) # stack pointer
|
||||
|
||||
ei # release interrupts
|
||||
j $ra # transfer back to setjmp()
|
||||
li $v0, 1 # return value of 1
|
||||
Reference in New Issue
Block a user