[GDB] Add GDB stub for remote debugging
See http://etherboot.org/wiki/dev/gdbstub for documentation.
This commit is contained in:
parent
831db76ff7
commit
04bc50f025
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@ -0,0 +1,209 @@
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/*
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* Interrupt Descriptor Table (IDT) setup and interrupt handlers for GDB stub.
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*/
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#include <virtaddr.h>
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#define SIZEOF_I386_REGS 32
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#define SIZEOF_I386_FLAGS 4
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/****************************************************************************
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* Interrupt Descriptor Table
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****************************************************************************
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*/
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.section ".data16"
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.globl idtr
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idtr:
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idt_limit:
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.word idt_length - 1
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idt_base:
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.long 0
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/* IDT entries have the following format:
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* offset_lo, segment selector, flags, offset_hi
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*
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* Since it is not possible to specify relocations in arbitrary
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* expressions like (int_overflow & 0xffff), we initialise the
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* IDT with entries in an incorrect format.
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*
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* The entries are shuffled into the correct format in init_librm().
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*/
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#define IDT_ENTRY_EMPTY(name) .word 0, 0, 0, 0
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#define IDT_ENTRY_PRESENT(name) \
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.long int_##name; \
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.word 0x8e00, VIRTUAL_CS
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.align 16
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idt:
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IDT_ENTRY_PRESENT(divide_error)
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IDT_ENTRY_PRESENT(debug_trap)
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IDT_ENTRY_EMPTY(non_maskable_interrupt)
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IDT_ENTRY_PRESENT(breakpoint)
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IDT_ENTRY_PRESENT(overflow)
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IDT_ENTRY_PRESENT(bound_range_exceeded)
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IDT_ENTRY_PRESENT(invalid_opcode)
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IDT_ENTRY_EMPTY(device_not_available)
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IDT_ENTRY_PRESENT(double_fault)
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IDT_ENTRY_EMPTY(coprocessor_segment_overrun)
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IDT_ENTRY_PRESENT(invalid_tss)
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IDT_ENTRY_PRESENT(segment_not_present)
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IDT_ENTRY_PRESENT(stack_segment_fault)
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IDT_ENTRY_PRESENT(general_protection)
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IDT_ENTRY_PRESENT(page_fault)
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idt_end:
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.equ idt_length, idt_end - idt
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/* The IDT entries are fixed up (once) in init_librm() */
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idt_fixed:
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.byte 0
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/****************************************************************************
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* idt_init (real-mode near call, 16-bit real-mode near return address)
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*
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* Initialise the IDT, called from init_librm.
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*
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* Parameters:
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* %eax : IDT base address
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*
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* Destroys %ax, %bx, and %di.
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****************************************************************************
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*/
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.section ".text16"
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.code16
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.globl idt_init
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idt_init:
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movl %eax, idt_base
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addl $idt, idt_base
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/* IDT entries are only fixed up once */
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movb idt_fixed, %al
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orb %al, %al
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jnz 2f
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movb $1, idt_fixed
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/* Shuffle IDT entries into the correct format */
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movb $(idt_length / 8), %al
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movw $idt, %bx
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or %al, %al
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jz 2f
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1:
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movw 2(%bx), %di
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xchg %di, 6(%bx)
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movw %di, 2(%bx)
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addw $8, %bx
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dec %al
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jnz 1b
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2:
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ret
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/****************************************************************************
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* Interrupt handlers
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****************************************************************************
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*/
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.section ".text"
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.code32
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/* POSIX signal numbers for reporting traps to GDB */
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#define SIGILL 4
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#define SIGTRAP 5
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#define SIGBUS 7
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#define SIGFPE 8
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#define SIGSEGV 11
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#define SIGSTKFLT 16
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int_divide_error:
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pushl $SIGFPE
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jmp do_interrupt
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int_debug_trap:
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int_breakpoint:
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pushl $SIGTRAP
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jmp do_interrupt
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int_overflow:
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int_bound_range_exceeded:
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pushl $SIGSTKFLT
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jmp do_interrupt
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int_invalid_opcode:
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pushl $SIGILL
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jmp do_interrupt
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int_double_fault:
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movl $SIGBUS, (%esp)
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jmp do_interrupt
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int_invalid_tss:
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int_segment_not_present:
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int_stack_segment_fault:
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int_general_protection:
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int_page_fault:
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movl $SIGSEGV, (%esp)
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jmp do_interrupt
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/* When invoked, the stack contains: eflags, cs, eip, signo. */
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#define IH_OFFSET_GDB_REGS ( 0 )
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#define IH_OFFSET_GDB_EIP ( IH_OFFSET_GDB_REGS + SIZEOF_I386_REGS )
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#define IH_OFFSET_GDB_EFLAGS ( IH_OFFSET_GDB_EIP + 4 )
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#define IH_OFFSET_GDB_SEG_REGS ( IH_OFFSET_GDB_EFLAGS + SIZEOF_I386_FLAGS )
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#define IH_OFFSET_GDB_END ( IH_OFFSET_GDB_SEG_REGS + 6 * 4 )
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#define IH_OFFSET_SIGNO ( IH_OFFSET_GDB_END )
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#define IH_OFFSET_OLD_EIP ( IH_OFFSET_SIGNO + 4 )
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#define IH_OFFSET_OLD_CS ( IH_OFFSET_OLD_EIP + 4 )
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#define IH_OFFSET_OLD_EFLAGS ( IH_OFFSET_OLD_CS + 4 )
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#define IH_OFFSET_END ( IH_OFFSET_OLD_EFLAGS + 4 )
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/* We also access the stack whilst still storing or restoring
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* the register snapshot. Since ESP is in flux, we need
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* special offsets.
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*/
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#define IH_OFFSET_FLUX_OLD_CS ( IH_OFFSET_OLD_CS - 44 )
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#define IH_OFFSET_FLUX_OLD_EFLAGS ( IH_OFFSET_OLD_EFLAGS - 40 )
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#define IH_OFFSET_FLUX_OLD_EIP ( IH_OFFSET_OLD_EIP - 36 )
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#define IH_OFFSET_FLUX_END ( IH_OFFSET_END - 20 )
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do_interrupt:
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/* Store CPU state in GDB register snapshot */
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pushl %gs
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pushl %fs
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pushl %es
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pushl %ds
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pushl %ss
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pushl IH_OFFSET_FLUX_OLD_CS(%esp)
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pushl IH_OFFSET_FLUX_OLD_EFLAGS(%esp)
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pushl IH_OFFSET_FLUX_OLD_EIP(%esp)
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pushl %edi
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pushl %esi
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pushl %ebp
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leal IH_OFFSET_FLUX_END(%esp), %edi
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pushl %edi /* old ESP */
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pushl %ebx
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pushl %edx
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pushl %ecx
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pushl %eax
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/* Call GDB stub exception handler */
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pushl %esp
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pushl (IH_OFFSET_SIGNO + 4)(%esp)
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call gdbstub_handler
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addl $8, %esp
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/* Restore CPU state from GDB register snapshot */
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popl %eax
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popl %ecx
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popl %edx
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popl %ebx
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addl $4, %esp /* Changing ESP currently not supported */
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popl %ebp
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popl %esi
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popl %edi
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popl IH_OFFSET_FLUX_OLD_EIP(%esp)
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popl IH_OFFSET_FLUX_OLD_EFLAGS(%esp)
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popl IH_OFFSET_FLUX_OLD_CS(%esp)
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popl %ss
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popl %ds
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popl %es
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popl %fs
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popl %gs
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addl $4, %esp /* drop signo */
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iret
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@ -0,0 +1,51 @@
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#ifndef GDBMACH_H
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#define GDBMACH_H
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/** @file
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*
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* GDB architecture specifics
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*
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* This file declares functions for manipulating the machine state and
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* debugging context.
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*
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*/
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typedef uint32_t gdbreg_t;
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/* The register snapshot, this must be in sync with interrupt handler and the
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* GDB protocol. */
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enum {
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GDBMACH_EAX,
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GDBMACH_ECX,
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GDBMACH_EDX,
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GDBMACH_EBX,
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GDBMACH_ESP,
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GDBMACH_EBP,
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GDBMACH_ESI,
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GDBMACH_EDI,
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GDBMACH_EIP,
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GDBMACH_EFLAGS,
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GDBMACH_CS,
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GDBMACH_SS,
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GDBMACH_DS,
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GDBMACH_ES,
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GDBMACH_FS,
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GDBMACH_GS,
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GDBMACH_NREGS,
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GDBMACH_SIZEOF_REGS = GDBMACH_NREGS * sizeof ( gdbreg_t )
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};
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static inline void gdbmach_set_pc ( gdbreg_t *regs, gdbreg_t pc ) {
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regs [ GDBMACH_EIP ] = pc;
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}
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static inline void gdbmach_set_single_step ( gdbreg_t *regs, int step ) {
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regs [ GDBMACH_EFLAGS ] &= ~( 1 << 8 ); /* Trace Flag (TF) */
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regs [ GDBMACH_EFLAGS ] |= ( step << 8 );
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}
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static inline void gdbmach_breakpoint ( void ) {
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__asm__ __volatile__ ( "int $3\n" );
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}
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#endif /* GDBMACH_H */
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@ -50,6 +50,7 @@
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.section ".data16"
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.section ".data16"
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.align 16
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.align 16
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gdt:
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gdt:
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gdtr: /* The first GDT entry is unused, the GDTR can fit here. */
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gdt_limit: .word gdt_length - 1
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gdt_limit: .word gdt_length - 1
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gdt_base: .long 0
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gdt_base: .long 0
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.word 0 /* padding */
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.word 0 /* padding */
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@ -127,7 +128,7 @@ init_librm:
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addr32 leal (%eax, %edi), %ebx
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addr32 leal (%eax, %edi), %ebx
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movl %ebx, _text16
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movl %ebx, _text16
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/* Store rm_ds and _data16, set up real_ds segment and set GDT base */
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/* Store rm_ds and _data16, set up real_ds segment */
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xorl %eax, %eax
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xorl %eax, %eax
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movw %ds, %ax
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movw %ds, %ax
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movw %ax, %cs:rm_ds
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movw %ax, %cs:rm_ds
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@ -136,8 +137,11 @@ init_librm:
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call set_seg_base
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call set_seg_base
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addr32 leal (%eax, %edi), %ebx
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addr32 leal (%eax, %edi), %ebx
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movl %ebx, _data16
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movl %ebx, _data16
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addl $gdt, %eax
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/* Set GDT and IDT base */
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movl %eax, gdt_base
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movl %eax, gdt_base
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addl $gdt, gdt_base
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call idt_init
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/* Restore registers */
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/* Restore registers */
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negl %edi
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negl %edi
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.section ".text16"
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.section ".text16"
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.code16
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.code16
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.weak idt_init
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set_seg_base:
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set_seg_base:
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1: movw %ax, 2(%bx)
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1: movw %ax, 2(%bx)
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rorl $16, %eax
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rorl $16, %eax
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movb %al, 4(%bx)
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movb %al, 4(%bx)
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movb %ah, 7(%bx)
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movb %ah, 7(%bx)
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roll $16, %eax
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roll $16, %eax
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idt_init: /* Reuse the return opcode here */
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ret
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ret
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/****************************************************************************
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/****************************************************************************
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@ -197,7 +203,8 @@ real_to_prot:
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/* Switch to protected mode */
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/* Switch to protected mode */
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cli
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cli
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data32 lgdt gdt
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data32 lgdt gdtr
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data32 lidt idtr
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movl %cr0, %eax
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movl %cr0, %eax
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orb $CR0_PE, %al
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orb $CR0_PE, %al
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movl %eax, %cr0
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movl %eax, %cr0
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@ -232,6 +239,14 @@ real_to_prot:
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/* Return to virtual address */
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/* Return to virtual address */
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ret
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ret
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/* Default IDTR with no interrupts */
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.section ".data16"
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.weak idtr
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idtr:
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rm_idtr:
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.word 0xffff /* limit */
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.long 0 /* base */
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/****************************************************************************
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/****************************************************************************
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* prot_to_real (protected-mode near call, 32-bit real-mode return address)
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* prot_to_real (protected-mode near call, 32-bit real-mode return address)
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*
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*
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@ -300,6 +315,9 @@ p2r_jump_target:
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movw %bp, %ss
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movw %bp, %ss
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movl %edx, %esp
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movl %edx, %esp
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/* Reset IDTR to the real-mode defaults */
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lidt rm_idtr
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/* Return to real-mode address */
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/* Return to real-mode address */
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data32 ret
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data32 ret
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@ -354,7 +372,8 @@ rm_ds: .word 0
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*/
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*/
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#define PC_OFFSET_GDT ( 0 )
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#define PC_OFFSET_GDT ( 0 )
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#define PC_OFFSET_IX86 ( PC_OFFSET_GDT + 8 /* pad to 8 to keep alignment */ )
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#define PC_OFFSET_IDT ( PC_OFFSET_GDT + 8 /* pad to 8 to keep alignment */ )
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#define PC_OFFSET_IX86 ( PC_OFFSET_IDT + 8 /* pad to 8 to keep alignment */ )
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#define PC_OFFSET_RETADDR ( PC_OFFSET_IX86 + SIZEOF_I386_ALL_REGS )
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#define PC_OFFSET_RETADDR ( PC_OFFSET_IX86 + SIZEOF_I386_ALL_REGS )
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#define PC_OFFSET_FUNCTION ( PC_OFFSET_RETADDR + 4 )
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#define PC_OFFSET_FUNCTION ( PC_OFFSET_RETADDR + 4 )
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#define PC_OFFSET_END ( PC_OFFSET_FUNCTION + 4 )
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#define PC_OFFSET_END ( PC_OFFSET_FUNCTION + 4 )
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@ -372,8 +391,9 @@ prot_call:
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pushw %ds
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pushw %ds
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pushw %ss
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pushw %ss
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pushw %cs
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pushw %cs
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subw $8, %sp
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subw $16, %sp
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movw %sp, %bp
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movw %sp, %bp
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sidt 8(%bp)
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sgdt (%bp)
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sgdt (%bp)
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/* For sanity's sake, clear the direction flag as soon as possible */
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/* For sanity's sake, clear the direction flag as soon as possible */
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@ -402,10 +422,11 @@ prot_call:
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.section ".text16"
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.section ".text16"
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.code16
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.code16
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1:
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1:
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/* Reload GDT, restore registers and flags and return */
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/* Reload GDT and IDT, restore registers and flags and return */
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movw %sp, %bp
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movw %sp, %bp
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lgdt (%bp)
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lgdt (%bp)
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addw $12, %sp /* also skip %cs and %ss */
|
lidt 8(%bp)
|
||||||
|
addw $20, %sp /* also skip %cs and %ss */
|
||||||
popw %ds
|
popw %ds
|
||||||
popw %es
|
popw %es
|
||||||
popw %fs
|
popw %fs
|
||||||
|
|
|
@ -164,6 +164,7 @@
|
||||||
#undef BUILD_ID /* Include a custom build ID string,
|
#undef BUILD_ID /* Include a custom build ID string,
|
||||||
* e.g "test-foo" */
|
* e.g "test-foo" */
|
||||||
#undef NULL_TRAP /* Attempt to catch NULL function calls */
|
#undef NULL_TRAP /* Attempt to catch NULL function calls */
|
||||||
|
#undef GDBSTUB /* Remote GDB debugging */
|
||||||
|
|
||||||
/* @END general.h */
|
/* @END general.h */
|
||||||
|
|
||||||
|
|
|
@ -198,3 +198,6 @@ REQUIRE_OBJECT ( sanboot_cmd );
|
||||||
#ifdef NULL_TRAP
|
#ifdef NULL_TRAP
|
||||||
REQUIRE_OBJECT ( nulltrap );
|
REQUIRE_OBJECT ( nulltrap );
|
||||||
#endif
|
#endif
|
||||||
|
#ifdef GDBSTUB
|
||||||
|
REQUIRE_OBJECT ( gdbidt );
|
||||||
|
#endif
|
||||||
|
|
|
@ -0,0 +1,330 @@
|
||||||
|
/*
|
||||||
|
* Copyright (C) 2008 Stefan Hajnoczi <stefanha@gmail.com>.
|
||||||
|
*
|
||||||
|
* 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 2 of the
|
||||||
|
* License, or 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, write to the Free Software
|
||||||
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||||
|
*/
|
||||||
|
|
||||||
|
/**
|
||||||
|
* @file
|
||||||
|
*
|
||||||
|
* GDB stub for remote debugging
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include <stdlib.h>
|
||||||
|
#include <stddef.h>
|
||||||
|
#include <stdio.h>
|
||||||
|
#include <ctype.h>
|
||||||
|
#include <assert.h>
|
||||||
|
#include <gpxe/process.h>
|
||||||
|
#include <gpxe/serial.h>
|
||||||
|
#include "gdbmach.h"
|
||||||
|
|
||||||
|
enum {
|
||||||
|
POSIX_EINVAL = 0x1c /* used to report bad arguments to GDB */
|
||||||
|
};
|
||||||
|
|
||||||
|
struct gdbstub {
|
||||||
|
int signo;
|
||||||
|
gdbreg_t *regs;
|
||||||
|
int exit_handler; /* leave interrupt handler */
|
||||||
|
|
||||||
|
void ( * parse ) ( struct gdbstub *stub, char ch );
|
||||||
|
uint8_t cksum1;
|
||||||
|
|
||||||
|
/* Buffer for payload data when parsing a packet. Once the
|
||||||
|
* packet has been received, this buffer is used to hold
|
||||||
|
* the reply payload. */
|
||||||
|
char payload [ 256 ];
|
||||||
|
int len;
|
||||||
|
};
|
||||||
|
|
||||||
|
/* Packet parser states */
|
||||||
|
static void gdbstub_state_new ( struct gdbstub *stub, char ch );
|
||||||
|
static void gdbstub_state_data ( struct gdbstub *stub, char ch );
|
||||||
|
static void gdbstub_state_cksum1 ( struct gdbstub *stub, char ch );
|
||||||
|
static void gdbstub_state_cksum2 ( struct gdbstub *stub, char ch );
|
||||||
|
static void gdbstub_state_wait_ack ( struct gdbstub *stub, char ch );
|
||||||
|
|
||||||
|
static uint8_t gdbstub_from_hex_digit ( char ch ) {
|
||||||
|
return ( isdigit ( ch ) ? ch - '0' : tolower ( ch ) - 'a' + 0xa ) & 0xf;
|
||||||
|
}
|
||||||
|
|
||||||
|
static uint8_t gdbstub_to_hex_digit ( uint8_t b ) {
|
||||||
|
b &= 0xf;
|
||||||
|
return ( b < 0xa ? '0' : 'a' - 0xa ) + b;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_from_hex_buf ( char *dst, char *src, int len ) {
|
||||||
|
while ( len-- > 0 ) {
|
||||||
|
*dst = gdbstub_from_hex_digit ( *src++ );
|
||||||
|
if ( len-- > 0 ) {
|
||||||
|
*dst = (*dst << 4) | gdbstub_from_hex_digit ( *src++ );
|
||||||
|
}
|
||||||
|
dst++;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_to_hex_buf ( char *dst, char *src, int len ) {
|
||||||
|
while ( len-- > 0 ) {
|
||||||
|
*dst++ = gdbstub_to_hex_digit ( *src >> 4 );
|
||||||
|
*dst++ = gdbstub_to_hex_digit ( *src++ );
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static uint8_t gdbstub_cksum ( char *data, int len ) {
|
||||||
|
uint8_t cksum = 0;
|
||||||
|
while ( len-- > 0 ) {
|
||||||
|
cksum += ( uint8_t ) *data++;
|
||||||
|
}
|
||||||
|
return cksum;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int gdbstub_getchar ( struct gdbstub *stub ) {
|
||||||
|
if ( stub->exit_handler ) {
|
||||||
|
return -1;
|
||||||
|
}
|
||||||
|
return serial_getc();
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_putchar ( struct gdbstub * stub __unused, char ch ) {
|
||||||
|
serial_putc ( ch );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_tx_packet ( struct gdbstub *stub ) {
|
||||||
|
uint8_t cksum = gdbstub_cksum ( stub->payload, stub->len );
|
||||||
|
int i;
|
||||||
|
|
||||||
|
gdbstub_putchar ( stub, '$' );
|
||||||
|
for ( i = 0; i < stub->len; i++ ) {
|
||||||
|
gdbstub_putchar ( stub, stub->payload [ i ] );
|
||||||
|
}
|
||||||
|
gdbstub_putchar ( stub, '#' );
|
||||||
|
gdbstub_putchar ( stub, gdbstub_to_hex_digit ( cksum >> 4 ) );
|
||||||
|
gdbstub_putchar ( stub, gdbstub_to_hex_digit ( cksum ) );
|
||||||
|
|
||||||
|
stub->parse = gdbstub_state_wait_ack;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* GDB commands */
|
||||||
|
static void gdbstub_send_ok ( struct gdbstub *stub ) {
|
||||||
|
stub->payload [ 0 ] = 'O';
|
||||||
|
stub->payload [ 1 ] = 'K';
|
||||||
|
stub->len = 2;
|
||||||
|
gdbstub_tx_packet ( stub );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_send_num_packet ( struct gdbstub *stub, char reply, int num ) {
|
||||||
|
stub->payload [ 0 ] = reply;
|
||||||
|
stub->payload [ 1 ] = gdbstub_to_hex_digit ( ( char ) num >> 4 );
|
||||||
|
stub->payload [ 2 ] = gdbstub_to_hex_digit ( ( char ) num );
|
||||||
|
stub->len = 3;
|
||||||
|
gdbstub_tx_packet ( stub );
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Format is arg1,arg2,...,argn:data where argn are hex integers and data is not an argument */
|
||||||
|
static int gdbstub_get_packet_args ( struct gdbstub *stub, unsigned long *args, int nargs, int *stop_idx ) {
|
||||||
|
int i;
|
||||||
|
char ch = 0;
|
||||||
|
int argc = 0;
|
||||||
|
unsigned long val = 0;
|
||||||
|
for ( i = 1; i < stub->len && argc < nargs; i++ ) {
|
||||||
|
ch = stub->payload [ i ];
|
||||||
|
if ( ch == ':' ) {
|
||||||
|
break;
|
||||||
|
} else if ( ch == ',' ) {
|
||||||
|
args [ argc++ ] = val;
|
||||||
|
val = 0;
|
||||||
|
} else {
|
||||||
|
val = ( val << 4 ) | gdbstub_from_hex_digit ( ch );
|
||||||
|
}
|
||||||
|
}
|
||||||
|
if ( stop_idx ) {
|
||||||
|
*stop_idx = i;
|
||||||
|
}
|
||||||
|
if ( argc < nargs ) {
|
||||||
|
args [ argc++ ] = val;
|
||||||
|
}
|
||||||
|
return ( ( i == stub->len || ch == ':' ) && argc == nargs );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_send_errno ( struct gdbstub *stub, int errno ) {
|
||||||
|
gdbstub_send_num_packet ( stub, 'E', errno );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_report_signal ( struct gdbstub *stub ) {
|
||||||
|
gdbstub_send_num_packet ( stub, 'S', stub->signo );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_read_regs ( struct gdbstub *stub ) {
|
||||||
|
gdbstub_to_hex_buf ( stub->payload, ( char * ) stub->regs, GDBMACH_SIZEOF_REGS );
|
||||||
|
stub->len = GDBMACH_SIZEOF_REGS * 2;
|
||||||
|
gdbstub_tx_packet ( stub );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_write_regs ( struct gdbstub *stub ) {
|
||||||
|
if ( stub->len != 1 + GDBMACH_SIZEOF_REGS * 2 ) {
|
||||||
|
gdbstub_send_errno ( stub, POSIX_EINVAL );
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
gdbstub_from_hex_buf ( ( char * ) stub->regs, &stub->payload [ 1 ], stub->len );
|
||||||
|
gdbstub_send_ok ( stub );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_read_mem ( struct gdbstub *stub ) {
|
||||||
|
unsigned long args [ 2 ];
|
||||||
|
if ( !gdbstub_get_packet_args ( stub, args, sizeof args / sizeof args [ 0 ], NULL ) ) {
|
||||||
|
gdbstub_send_errno ( stub, POSIX_EINVAL );
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
args [ 1 ] = ( args [ 1 ] < sizeof stub->payload / 2 ) ? args [ 1 ] : sizeof stub->payload / 2;
|
||||||
|
gdbstub_to_hex_buf ( stub->payload, ( char * ) args [ 0 ], args [ 1 ] );
|
||||||
|
stub->len = args [ 1 ] * 2;
|
||||||
|
gdbstub_tx_packet ( stub );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_write_mem ( struct gdbstub *stub ) {
|
||||||
|
unsigned long args [ 2 ];
|
||||||
|
int colon;
|
||||||
|
if ( !gdbstub_get_packet_args ( stub, args, sizeof args / sizeof args [ 0 ], &colon ) ||
|
||||||
|
colon >= stub->len || stub->payload [ colon ] != ':' ||
|
||||||
|
( stub->len - colon - 1 ) % 2 != 0 ) {
|
||||||
|
gdbstub_send_errno ( stub, POSIX_EINVAL );
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
gdbstub_from_hex_buf ( ( char * ) args [ 0 ], &stub->payload [ colon + 1 ], stub->len - colon - 1 );
|
||||||
|
gdbstub_send_ok ( stub );
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_continue ( struct gdbstub *stub, int single_step ) {
|
||||||
|
gdbreg_t pc;
|
||||||
|
if ( stub->len > 1 && gdbstub_get_packet_args ( stub, &pc, 1, NULL ) ) {
|
||||||
|
gdbmach_set_pc ( stub->regs, pc );
|
||||||
|
}
|
||||||
|
gdbmach_set_single_step ( stub->regs, single_step );
|
||||||
|
stub->exit_handler = 1;
|
||||||
|
/* Reply will be sent when we hit the next breakpoint or interrupt */
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_rx_packet ( struct gdbstub *stub ) {
|
||||||
|
switch ( stub->payload [ 0 ] ) {
|
||||||
|
case '?':
|
||||||
|
gdbstub_report_signal ( stub );
|
||||||
|
break;
|
||||||
|
case 'g':
|
||||||
|
gdbstub_read_regs ( stub );
|
||||||
|
break;
|
||||||
|
case 'G':
|
||||||
|
gdbstub_write_regs ( stub );
|
||||||
|
break;
|
||||||
|
case 'm':
|
||||||
|
gdbstub_read_mem ( stub );
|
||||||
|
break;
|
||||||
|
case 'M':
|
||||||
|
gdbstub_write_mem ( stub );
|
||||||
|
break;
|
||||||
|
case 'c':
|
||||||
|
gdbstub_continue ( stub, 0 );
|
||||||
|
break;
|
||||||
|
case 's':
|
||||||
|
gdbstub_continue ( stub, 1 );
|
||||||
|
break;
|
||||||
|
default:
|
||||||
|
stub->len = 0;
|
||||||
|
gdbstub_tx_packet ( stub );
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/* GDB packet parser */
|
||||||
|
static void gdbstub_state_new ( struct gdbstub *stub, char ch ) {
|
||||||
|
if ( ch == '$' ) {
|
||||||
|
stub->len = 0;
|
||||||
|
stub->parse = gdbstub_state_data;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_state_data ( struct gdbstub *stub, char ch ) {
|
||||||
|
if ( ch == '#' ) {
|
||||||
|
stub->parse = gdbstub_state_cksum1;
|
||||||
|
} else if ( ch == '$' ) {
|
||||||
|
stub->len = 0; /* retry new packet */
|
||||||
|
} else {
|
||||||
|
/* If the length exceeds our buffer, let the checksum fail */
|
||||||
|
if ( stub->len < ( int ) sizeof stub->payload ) {
|
||||||
|
stub->payload [ stub->len++ ] = ch;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_state_cksum1 ( struct gdbstub *stub, char ch ) {
|
||||||
|
stub->cksum1 = gdbstub_from_hex_digit ( ch ) << 4;
|
||||||
|
stub->parse = gdbstub_state_cksum2;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_state_cksum2 ( struct gdbstub *stub, char ch ) {
|
||||||
|
uint8_t their_cksum;
|
||||||
|
uint8_t our_cksum;
|
||||||
|
|
||||||
|
stub->parse = gdbstub_state_new;
|
||||||
|
their_cksum = stub->cksum1 + gdbstub_from_hex_digit ( ch );
|
||||||
|
our_cksum = gdbstub_cksum ( stub->payload, stub->len );
|
||||||
|
if ( their_cksum == our_cksum ) {
|
||||||
|
gdbstub_putchar ( stub, '+' );
|
||||||
|
if ( stub->len > 0 ) {
|
||||||
|
gdbstub_rx_packet ( stub );
|
||||||
|
}
|
||||||
|
} else {
|
||||||
|
gdbstub_putchar ( stub, '-' );
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_state_wait_ack ( struct gdbstub *stub, char ch ) {
|
||||||
|
if ( ch == '+' ) {
|
||||||
|
stub->parse = gdbstub_state_new;
|
||||||
|
} else if ( ch == '-' ) {
|
||||||
|
gdbstub_tx_packet ( stub ); /* retransmit */
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void gdbstub_parse ( struct gdbstub *stub, char ch ) {
|
||||||
|
stub->parse ( stub, ch );
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct gdbstub stub = {
|
||||||
|
.parse = gdbstub_state_new
|
||||||
|
};
|
||||||
|
|
||||||
|
__cdecl void gdbstub_handler ( int signo, gdbreg_t *regs ) {
|
||||||
|
int ch;
|
||||||
|
stub.signo = signo;
|
||||||
|
stub.regs = regs;
|
||||||
|
stub.exit_handler = 0;
|
||||||
|
gdbstub_report_signal ( &stub );
|
||||||
|
while ( ( ch = gdbstub_getchar( &stub ) ) != -1 ) {
|
||||||
|
gdbstub_parse ( &stub, ch );
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Activity monitor to detect packets from GDB when we are not active */
|
||||||
|
static void gdbstub_activity_step ( struct process *process __unused ) {
|
||||||
|
if ( serial_ischar() ) {
|
||||||
|
gdbmach_breakpoint();
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
struct process gdbstub_activity_process __permanent_process = {
|
||||||
|
.step = gdbstub_activity_step,
|
||||||
|
};
|
Reference in New Issue