[PATCH,RFC 2.6.14 10/15] KGDB: ARM-specific changes

From: Tom Rini (trini_at_kernel.crashing.org)
Date: 11/10/05

  • Next message: Tom Rini: "[PATCH,RFC 2.6.14 07/15] x86_64: Add a notifier hook to the "no context" part of do_page_fault"
    To: Andrew Morton <akpm@osdl.org>
    Date:	Thu, 10 Nov 2005 11:42:50 -0500
    
    

    This adds a backend, written by Deepak Saxena <dsaxena@plexity.net> and George
    Davis <gdavis@mvista.com> as well as support for the TI OMAP boards, ADI
    Coyote, PXA2xx, and ARM Versatile. Geoff Levand <geoffrey.levand@am.sony.com>
    Nicolas Pitre, and Manish Lachwani have contributed various fixups here as
    well. This should only require (on boards that don't have a custom uart)
    registering the uart with KGDB to add any other boards, or using kgdboe it
    should Just Work.

     arch/arm/kernel/Makefile | 1
     arch/arm/kernel/kgdb-jmp.S | 30 ++++
     arch/arm/kernel/kgdb.c | 208 ++++++++++++++++++++++++++++++++++
     arch/arm/kernel/setup.c | 5
     arch/arm/kernel/traps.c | 11 +
     arch/arm/mach-ixp2000/core.c | 5
     arch/arm/mach-ixp2000/ixdp2x01.c | 6
     arch/arm/mach-ixp4xx/coyote-setup.c | 5
     arch/arm/mach-ixp4xx/ixdp425-setup.c | 12 +
     arch/arm/mach-omap1/board-osk.c | 2
     arch/arm/mach-omap1/serial.c | 4
     arch/arm/mach-pxa/Makefile | 1
     arch/arm/mach-pxa/kgdb-serial.c | 98 ++++++++++++++++
     arch/arm/mach-versatile/kgdb_serial.c | 121 +++++++++++++++++++
     arch/arm/mm/extable.c | 7 +
     drivers/serial/amba-pl011.c | 2
     include/asm-arm/kgdb.h | 87 ++++++++++++++
     include/asm-arm/system.h | 41 ++++++
     lib/Kconfig.debug | 2
     19 files changed, 642 insertions(+), 6 deletions(-)

    Index: linux-2.6.14/arch/arm/kernel/kgdb.c
    ===================================================================
    --- /dev/null
    +++ linux-2.6.14/arch/arm/kernel/kgdb.c
    @@ -0,0 +1,208 @@
    +/*
    + * arch/arm/kernel/kgdb.c
    + *
    + * ARM KGDB support
    + *
    + * Copyright (c) 2002-2004 MontaVista Software, Inc
    + *
    + * Authors: George Davis <davis_g@mvista.com>
    + * Deepak Saxena <dsaxena@plexity.net>
    + */
    +#include <linux/config.h>
    +#include <linux/types.h>
    +#include <linux/kernel.h>
    +#include <linux/signal.h>
    +#include <linux/sched.h>
    +#include <linux/mm.h>
    +#include <linux/spinlock.h>
    +#include <linux/personality.h>
    +#include <linux/ptrace.h>
    +#include <linux/elf.h>
    +#include <linux/interrupt.h>
    +#include <linux/init.h>
    +#include <linux/kgdb.h>
    +
    +#include <asm/atomic.h>
    +#include <asm/io.h>
    +#include <asm/pgtable.h>
    +#include <asm/system.h>
    +#include <asm/uaccess.h>
    +#include <asm/unistd.h>
    +#include <asm/ptrace.h>
    +#include <asm/traps.h>
    +
    +/* Make a local copy of the registers passed into the handler (bletch) */
    +void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
    +{
    + int regno;
    +
    + /* Initialize all to zero (??) */
    + for (regno = 0; regno < GDB_MAX_REGS; regno++)
    + gdb_regs[regno] = 0;
    +
    + gdb_regs[_R0] = kernel_regs->ARM_r0;
    + gdb_regs[_R1] = kernel_regs->ARM_r1;
    + gdb_regs[_R2] = kernel_regs->ARM_r2;
    + gdb_regs[_R3] = kernel_regs->ARM_r3;
    + gdb_regs[_R4] = kernel_regs->ARM_r4;
    + gdb_regs[_R5] = kernel_regs->ARM_r5;
    + gdb_regs[_R6] = kernel_regs->ARM_r6;
    + gdb_regs[_R7] = kernel_regs->ARM_r7;
    + gdb_regs[_R8] = kernel_regs->ARM_r8;
    + gdb_regs[_R9] = kernel_regs->ARM_r9;
    + gdb_regs[_R10] = kernel_regs->ARM_r10;
    + gdb_regs[_FP] = kernel_regs->ARM_fp;
    + gdb_regs[_IP] = kernel_regs->ARM_ip;
    + gdb_regs[_SP] = kernel_regs->ARM_sp;
    + gdb_regs[_LR] = kernel_regs->ARM_lr;
    + gdb_regs[_PC] = kernel_regs->ARM_pc;
    + gdb_regs[_CPSR] = kernel_regs->ARM_cpsr;
    +}
    +
    +/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
    +void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
    +{
    + kernel_regs->ARM_r0 = gdb_regs[_R0];
    + kernel_regs->ARM_r1 = gdb_regs[_R1];
    + kernel_regs->ARM_r2 = gdb_regs[_R2];
    + kernel_regs->ARM_r3 = gdb_regs[_R3];
    + kernel_regs->ARM_r4 = gdb_regs[_R4];
    + kernel_regs->ARM_r5 = gdb_regs[_R5];
    + kernel_regs->ARM_r6 = gdb_regs[_R6];
    + kernel_regs->ARM_r7 = gdb_regs[_R7];
    + kernel_regs->ARM_r8 = gdb_regs[_R8];
    + kernel_regs->ARM_r9 = gdb_regs[_R9];
    + kernel_regs->ARM_r10 = gdb_regs[_R10];
    + kernel_regs->ARM_fp = gdb_regs[_FP];
    + kernel_regs->ARM_ip = gdb_regs[_IP];
    + kernel_regs->ARM_sp = gdb_regs[_SP];
    + kernel_regs->ARM_lr = gdb_regs[_LR];
    + kernel_regs->ARM_pc = gdb_regs[_PC];
    + kernel_regs->ARM_cpsr = gdb_regs[GDB_MAX_REGS - 1];
    +}
    +
    +static inline struct pt_regs *kgdb_get_user_regs(struct task_struct *task)
    +{
    + return (struct pt_regs *)
    + ((unsigned long)task->thread_info + THREAD_SIZE -
    + 8 - sizeof(struct pt_regs));
    +}
    +
    +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
    + struct task_struct *task)
    +{
    + int regno;
    + struct pt_regs *thread_regs;
    +
    + /* Just making sure... */
    + if (task == NULL)
    + return;
    +
    + /* Initialize to zero */
    + for (regno = 0; regno < GDB_MAX_REGS; regno++)
    + gdb_regs[regno] = 0;
    +
    + /* Otherwise, we have only some registers from switch_to() */
    + thread_regs = kgdb_get_user_regs(task);
    + gdb_regs[_R0] = thread_regs->ARM_r0; /* Not really valid? */
    + gdb_regs[_R1] = thread_regs->ARM_r1; /* " " */
    + gdb_regs[_R2] = thread_regs->ARM_r2; /* " " */
    + gdb_regs[_R3] = thread_regs->ARM_r3; /* " " */
    + gdb_regs[_R4] = thread_regs->ARM_r4;
    + gdb_regs[_R5] = thread_regs->ARM_r5;
    + gdb_regs[_R6] = thread_regs->ARM_r6;
    + gdb_regs[_R7] = thread_regs->ARM_r7;
    + gdb_regs[_R8] = thread_regs->ARM_r8;
    + gdb_regs[_R9] = thread_regs->ARM_r9;
    + gdb_regs[_R10] = thread_regs->ARM_r10;
    + gdb_regs[_FP] = thread_regs->ARM_fp;
    + gdb_regs[_IP] = thread_regs->ARM_ip;
    + gdb_regs[_SP] = thread_regs->ARM_sp;
    + gdb_regs[_LR] = thread_regs->ARM_lr;
    + gdb_regs[_PC] = thread_regs->ARM_pc;
    + gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
    +}
    +
    +static int compiled_break;
    +
    +int kgdb_arch_handle_exception(int exception_vector, int signo,
    + int err_code, char *remcom_in_buffer,
    + char *remcom_out_buffer,
    + struct pt_regs *linux_regs)
    +{
    + long addr;
    + char *ptr;
    +
    + switch (remcom_in_buffer[0]) {
    + case 'c':
    + kgdb_contthread = NULL;
    +
    + /*
    + * Try to read optional parameter, pc unchanged if no parm.
    + * If this was a compiled breakpoint, we need to move
    + * to the next instruction or we will just breakpoint
    + * over and over again.
    + */
    + ptr = &remcom_in_buffer[1];
    + if (kgdb_hex2long(&ptr, &addr)) {
    + linux_regs->ARM_pc = addr;
    + } else if (compiled_break == 1) {
    + linux_regs->ARM_pc += 4;
    + }
    +
    + compiled_break = 0;
    +
    + return 0;
    + }
    +
    + return -1;
    +}
    +
    +static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
    +{
    + kgdb_handle_exception(1, SIGTRAP, 0, regs);
    +
    + return 0;
    +}
    +
    +static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
    +{
    + compiled_break = 1;
    + kgdb_handle_exception(1, SIGTRAP, 0, regs);
    +
    + return 0;
    +}
    +
    +static struct undef_hook kgdb_brkpt_hook = {
    + .instr_mask = 0xffffffff,
    + .instr_val = KGDB_BREAKINST,
    + .fn = kgdb_brk_fn
    +};
    +
    +static struct undef_hook kgdb_compiled_brkpt_hook = {
    + .instr_mask = 0xffffffff,
    + .instr_val = KGDB_COMPILED_BREAK,
    + .fn = kgdb_compiled_brk_fn
    +};
    +
    +/*
    + * Register our undef instruction hooks with ARM undef core.
    + * We regsiter a hook specifically looking for the KGB break inst
    + * and we handle the normal undef case within the do_undefinstr
    + * handler.
    + */
    +int kgdb_arch_init(void)
    +{
    + register_undef_hook(&kgdb_brkpt_hook);
    + register_undef_hook(&kgdb_compiled_brkpt_hook);
    +
    + return 0;
    +}
    +
    +struct kgdb_arch arch_kgdb_ops = {
    +#ifndef __ARMEB__
    + .gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
    +#else
    + .gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
    +#endif
    +};
    Index: linux-2.6.14/arch/arm/kernel/kgdb-jmp.S
    ===================================================================
    --- /dev/null
    +++ linux-2.6.14/arch/arm/kernel/kgdb-jmp.S
    @@ -0,0 +1,30 @@
    +/*
    + * arch/arm/kernel/kgdb-jmp.S
    + *
    + * Trivial setjmp and longjmp procedures to support bus error recovery
    + * which may occur during kgdb memory read/write operations.
    + *
    + * Author: MontaVista Software, Inc. <source@mvista.com>
    + * source@mvista.com
    + *
    + * 2002-2005 (c) MontaVista Software, Inc. This file is licensed under the
    + * terms of the GNU General Public License version 2. This program as licensed
    + * "as is" without any warranty of any kind, whether express or implied.
    + */
    +#include <linux/linkage.h>
    +
    +ENTRY (kgdb_fault_setjmp)
    + /* Save registers */
    + stmia r0, {r0-r14}
    + str lr,[r0, #60]
    + mrs r1,cpsr
    + str r1,[r0,#64]
    + ldr r1,[r0,#4]
    + mov r0, #0
    + mov pc,lr
    +
    +ENTRY (kgdb_fault_longjmp)
    + /* Restore registers */
    + mov r1,#1
    + str r1,[r0]
    + ldmia r0,{r0-pc}^
    Index: linux-2.6.14/arch/arm/kernel/Makefile
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/kernel/Makefile
    +++ linux-2.6.14/arch/arm/kernel/Makefile
    @@ -19,6 +19,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o
     obj-$(CONFIG_ISA_DMA) += dma-isa.o
     obj-$(CONFIG_PCI) += bios32.o
     obj-$(CONFIG_SMP) += smp.o
    +obj-$(CONFIG_KGDB) += kgdb.o kgdb-jmp.o
     
     obj-$(CONFIG_IWMMXT) += iwmmxt.o
     AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt
    Index: linux-2.6.14/arch/arm/kernel/setup.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/kernel/setup.c
    +++ linux-2.6.14/arch/arm/kernel/setup.c
    @@ -785,6 +785,11 @@ void __init setup_arch(char **cmdline_p)
             conswitchp = &dummy_con;
     #endif
     #endif
    +
    +#if defined(CONFIG_KGDB)
    + extern void __init early_trap_init(void);
    + early_trap_init();
    +#endif
     }
     
     
    Index: linux-2.6.14/arch/arm/kernel/traps.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/kernel/traps.c
    +++ linux-2.6.14/arch/arm/kernel/traps.c
    @@ -270,6 +270,7 @@ asmlinkage void do_undefinstr(struct pt_
             unsigned int instr;
             struct undef_hook *hook;
             siginfo_t info;
    + mm_segment_t fs;
             void __user *pc;
     
             /*
    @@ -279,12 +280,15 @@ asmlinkage void do_undefinstr(struct pt_
              */
             regs->ARM_pc -= correction;
     
    + fs = get_fs();
    + set_fs(KERNEL_DS);
             pc = (void __user *)instruction_pointer(regs);
             if (thumb_mode(regs)) {
                     get_user(instr, (u16 __user *)pc);
             } else {
                     get_user(instr, (u32 __user *)pc);
             }
    + set_fs(fs);
     
             spin_lock_irq(&undef_lock);
             list_for_each_entry(hook, &undef_hook, node) {
    @@ -670,6 +674,13 @@ EXPORT_SYMBOL(abort);
     
     void __init trap_init(void)
     {
    +#if defined(CONFIG_KGDB)
    + return;
    +}
    +
    +void __init early_trap_init(void)
    +{
    +#endif
             extern char __stubs_start[], __stubs_end[];
             extern char __vectors_start[], __vectors_end[];
             extern char __kuser_helper_start[], __kuser_helper_end[];
    Index: linux-2.6.14/arch/arm/mach-ixp2000/core.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mach-ixp2000/core.c
    +++ linux-2.6.14/arch/arm/mach-ixp2000/core.c
    @@ -34,6 +34,7 @@
     #include <asm/system.h>
     #include <asm/tlbflush.h>
     #include <asm/pgtable.h>
    +#include <asm/kgdb.h>
     
     #include <asm/mach/map.h>
     #include <asm/mach/time.h>
    @@ -144,6 +145,10 @@ void __init ixp2000_map_io(void)
     
             iotable_init(ixp2000_io_desc, ARRAY_SIZE(ixp2000_io_desc));
     
    +#ifdef CONFIG_KGDB_8250
    + kgdb8250_add_port(0, &ixp2000_serial_port);
    +#endif
    +
             /* Set slowport to 8-bit mode. */
             ixp2000_reg_write(IXP2000_SLOWPORT_FRM, 1);
     }
    Index: linux-2.6.14/arch/arm/mach-ixp2000/ixdp2x01.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mach-ixp2000/ixdp2x01.c
    +++ linux-2.6.14/arch/arm/mach-ixp2000/ixdp2x01.c
    @@ -38,6 +38,7 @@
     #include <asm/system.h>
     #include <asm/hardware.h>
     #include <asm/mach-types.h>
    +#include <asm/kgdb.h>
     
     #include <asm/mach/pci.h>
     #include <asm/mach/map.h>
    @@ -175,6 +176,11 @@ static void __init ixdp2x01_map_io(void)
     
             early_serial_setup(&ixdp2x01_serial_ports[0]);
             early_serial_setup(&ixdp2x01_serial_ports[1]);
    +
    +#ifdef CONFIG_KGDB_8250
    + kgdb8250_add_port(0, &ixdp2x01_serial_ports[0]);
    + kgdb8250_add_port(1, &ixdp2x01_serial_ports[1]);
    +#endif
     }
     
     
    Index: linux-2.6.14/arch/arm/mach-ixp4xx/coyote-setup.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mach-ixp4xx/coyote-setup.c
    +++ linux-2.6.14/arch/arm/mach-ixp4xx/coyote-setup.c
    @@ -91,9 +91,12 @@ static void __init coyote_init(void)
                     coyote_uart_data[0].irq = IRQ_IXP4XX_UART1;
             }
     
    -
             ixp4xx_sys_init();
             platform_add_devices(coyote_devices, ARRAY_SIZE(coyote_devices));
    +
    +#ifdef CONFIG_KGDB_8250
    + kgdb8250_add_port(0, &coyote_serial_port);
    +#endif
     }
     
     #ifdef CONFIG_ARCH_ADI_COYOTE
    Index: linux-2.6.14/arch/arm/mach-ixp4xx/ixdp425-setup.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mach-ixp4xx/ixdp425-setup.c
    +++ linux-2.6.14/arch/arm/mach-ixp4xx/ixdp425-setup.c
    @@ -23,6 +23,7 @@
     #include <asm/irq.h>
     #include <asm/mach/arch.h>
     #include <asm/mach/flash.h>
    +#include <asm/kgdb.h>
     
     static struct flash_platform_data ixdp425_flash_data = {
             .map_name = "cfi_probe",
    @@ -77,7 +78,8 @@ static struct plat_serial8250_port ixdp4
                     .mapbase = IXP4XX_UART1_BASE_PHYS,
                     .membase = (char *)IXP4XX_UART1_BASE_VIRT + REG_OFFSET,
                     .irq = IRQ_IXP4XX_UART1,
    - .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
    + .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
    + UPF_SHARE_IRQ,
                     .iotype = UPIO_MEM,
                     .regshift = 2,
                     .uartclk = IXP4XX_UART_XTAL,
    @@ -86,7 +88,8 @@ static struct plat_serial8250_port ixdp4
                     .mapbase = IXP4XX_UART2_BASE_PHYS,
                     .membase = (char *)IXP4XX_UART2_BASE_VIRT + REG_OFFSET,
                     .irq = IRQ_IXP4XX_UART1,
    - .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
    + .flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
    + UPF_SHARE_IRQ,
                     .iotype = UPIO_MEM,
                     .regshift = 2,
                     .uartclk = IXP4XX_UART_XTAL,
    @@ -121,6 +124,11 @@ static void __init ixdp425_init(void)
             }
     
             platform_add_devices(ixdp425_devices, ARRAY_SIZE(ixdp425_devices));
    +
    +#ifdef CONFIG_KGDB_8250
    + kgdb8250_add_port(0, &ixdp425_serial_ports[0]);
    + kgdb8250_add_port(1, &ixdp425_serial_ports[1]);
    +#endif
     }
     
     #ifdef CONFIG_ARCH_IXDP425
    Index: linux-2.6.14/arch/arm/mach-omap1/board-osk.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mach-omap1/board-osk.c
    +++ linux-2.6.14/arch/arm/mach-omap1/board-osk.c
    @@ -46,7 +46,7 @@
     #include <asm/arch/tc.h>
     #include <asm/arch/common.h>
     
    -static int __initdata osk_serial_ports[OMAP_MAX_NR_PORTS] = {1, 0, 0};
    +static int __initdata osk_serial_ports[OMAP_MAX_NR_PORTS] = {1, 1, 1};
     
     static struct mtd_partition osk_partitions[] = {
             /* bootloader (U-Boot, etc) in first sector */
    Index: linux-2.6.14/arch/arm/mach-omap1/serial.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mach-omap1/serial.c
    +++ linux-2.6.14/arch/arm/mach-omap1/serial.c
    @@ -15,6 +15,7 @@
     #include <linux/delay.h>
     #include <linux/serial.h>
     #include <linux/tty.h>
    +#include <linux/kgdb.h>
     #include <linux/serial_8250.h>
     #include <linux/serial_reg.h>
     
    @@ -194,6 +195,9 @@ void __init omap_serial_init(int ports[O
                             break;
                     }
                     omap_serial_reset(&serial_platform_data[i]);
    +#ifdef CONFIG_KGDB_8250
    + kgdb8250_add_platform_port(i, &serial_platform_data[i]);
    +#endif
             }
     }
     
    Index: linux-2.6.14/arch/arm/mach-pxa/kgdb-serial.c
    ===================================================================
    --- /dev/null
    +++ linux-2.6.14/arch/arm/mach-pxa/kgdb-serial.c
    @@ -0,0 +1,98 @@
    +/*
    + * linux/arch/arm/mach-pxa/kgdb-serial.c
    + *
    + * Provides low level kgdb serial support hooks for PXA2xx boards
    + *
    + * Author: Nicolas Pitre
    + * Copyright: (C) 2002-2005 MontaVista Software Inc.
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of the GNU General Public License version 2 as
    + * published by the Free Software Foundation.
    + */
    +
    +#include <linux/config.h>
    +#include <linux/serial_reg.h>
    +#include <linux/kgdb.h>
    +#include <asm/processor.h>
    +#include <asm/hardware.h>
    +#include <asm/arch/pxa-regs.h>
    +
    +#if defined(CONFIG_KGDB_PXA_FFUART)
    +
    +#define UART FFUART
    +#define CKEN_UART CKEN6_FFUART
    +#define GPIO_RX_MD GPIO34_FFRXD_MD
    +#define GPIO_TX_MD GPIO39_FFTXD_MD
    +
    +#elif defined(CONFIG_KGDB_PXA_BTUART)
    +
    +#define UART BTUART
    +#define CKEN_UART CKEN7_BTUART
    +#define GPIO_RX_MD GPIO42_BTRXD_MD
    +#define GPIO_TX_MD GPIO43_BTTXD_MD
    +
    +#elif defined(CONFIG_KGDB_PXA_STUART)
    +
    +#define UART STUART
    +#define CKEN_UART CKEN5_STUART
    +#define GPIO_RX_MD GPIO46_STRXD_MD
    +#define GPIO_TX_MD GPIO47_STTXD_MD
    +
    +#endif
    +
    +#define UART_BAUDRATE (CONFIG_KGDB_BAUDRATE)
    +
    +static volatile unsigned long *port = (unsigned long *)&UART;
    +
    +static int kgdb_serial_init(void)
    +{
    + pxa_set_cken(CKEN_UART, 1);
    + pxa_gpio_mode(GPIO_RX_MD);
    + pxa_gpio_mode(GPIO_TX_MD);
    +
    + port[UART_IER] = 0;
    + port[UART_LCR] = LCR_DLAB;
    + port[UART_DLL] = ((921600 / UART_BAUDRATE) & 0xff);
    + port[UART_DLM] = ((921600 / UART_BAUDRATE) >> 8);
    + port[UART_LCR] = LCR_WLS1 | LCR_WLS0;
    + port[UART_MCR] = 0;
    + port[UART_IER] = IER_UUE;
    + port[UART_FCR] = FCR_ITL_16;
    +
    + return 0;
    +}
    +
    +static void kgdb_serial_putchar(int c)
    +{
    + if (!(CKEN & CKEN_UART) || port[UART_IER] != IER_UUE)
    + kgdb_serial_init();
    + while (!(port[UART_LSR] & LSR_TDRQ))
    + cpu_relax();
    + port[UART_TX] = c;
    +}
    +
    +static void kgdb_serial_flush(void)
    +{
    + if ((CKEN & CKEN_UART) && (port[UART_IER] & IER_UUE))
    + while (!(port[UART_LSR] & LSR_TEMT))
    + cpu_relax();
    +}
    +
    +static int kgdb_serial_getchar(void)
    +{
    + unsigned char c;
    + if (!(CKEN & CKEN_UART) || port[UART_IER] != IER_UUE)
    + kgdb_serial_init();
    + while (!(port[UART_LSR] & UART_LSR_DR))
    + cpu_relax();
    + c = port[UART_RX];
    + return c;
    +}
    +
    +struct kgdb_io kgdb_io_ops = {
    + .init = kgdb_serial_init,
    + .write_char = kgdb_serial_putchar,
    + .flush = kgdb_serial_flush,
    + .read_char = kgdb_serial_getchar,
    +};
    Index: linux-2.6.14/arch/arm/mach-pxa/Makefile
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mach-pxa/Makefile
    +++ linux-2.6.14/arch/arm/mach-pxa/Makefile
    @@ -25,6 +25,7 @@ obj-$(CONFIG_LEDS) += $(led-y)
     
     # Misc features
     obj-$(CONFIG_PM) += pm.o sleep.o
    +obj-$(CONFIG_KGDB_PXA_SERIAL) += kgdb-serial.o
     
     ifeq ($(CONFIG_PXA27x),y)
     obj-$(CONFIG_PM) += standby.o
    Index: linux-2.6.14/arch/arm/mach-versatile/kgdb_serial.c
    ===================================================================
    --- /dev/null
    +++ linux-2.6.14/arch/arm/mach-versatile/kgdb_serial.c
    @@ -0,0 +1,121 @@
    +/*
    + * arch/arm/mach-versatile/kgdb_serial.c
    + *
    + * Author: Manish Lachwani, mlachwani@mvista.com
    + *
    + * 2005 (c) MontaVista Software, Inc. This file is licensed under
    + * the terms of the GNU General Public License version 2. This program
    + * is licensed "as is" without any warranty of any kind, whether express
    + * or implied.
    + *
    + * Support for KGDB on ARM Versatile.
    + */
    +#include <linux/config.h>
    +#include <linux/serial_reg.h>
    +#include <linux/kgdb.h>
    +#include <asm/io.h>
    +#include <asm/processor.h>
    +#include <asm/hardware.h>
    +#include <asm/hardware/amba_serial.h>
    +#include <asm/arch-versatile/hardware.h>
    +
    +#define ARM_BAUD_38400 23
    +/*
    + * Functions that will be used later
    + */
    +#define UART_GET_INT_STATUS(p) readb((p) + UART010_IIR)
    +#define UART_GET_MIS(p) readw((p) + UART011_MIS)
    +#define UART_PUT_ICR(p, c) writel((c), (p) + UART010_ICR)
    +#define UART_GET_FR(p) readb((p) + UART01x_FR)
    +#define UART_GET_CHAR(p) readb((p) + UART01x_DR)
    +#define UART_PUT_CHAR(p, c) writel((c), (p) + UART01x_DR)
    +#define UART_GET_RSR(p) readb((p) + UART01x_RSR)
    +#define UART_GET_CR(p) readb((p) + UART010_CR)
    +#define UART_PUT_CR(p,c) writel((c), (p) + UART010_CR)
    +#define UART_GET_LCRL(p) readb((p) + UART010_LCRL)
    +#define UART_PUT_LCRL(p,c) writel((c), (p) + UART010_LCRL)
    +#define UART_GET_LCRM(p) readb((p) + UART010_LCRM)
    +#define UART_PUT_LCRM(p,c) writel((c), (p) + UART010_LCRM)
    +#define UART_GET_LCRH(p) readb((p) + UART010_LCRH)
    +#define UART_PUT_LCRH(p,c) writel((c), (p) + UART010_LCRH)
    +#define UART_RX_DATA(s) (((s) & UART01x_FR_RXFE) == 0)
    +#define UART_TX_READY(s) (((s) & UART01x_FR_TXFF) == 0)
    +#define UART_TX_EMPTY(p) ((UART_GET_FR(p) & UART01x_FR_TMSK) == 0)
    +
    +/*
    + * KGDB IRQ
    + */
    +static int kgdb_irq = 12;
    +static volatile unsigned char *port = NULL;
    +
    +static int kgdb_serial_init(void)
    +{
    + int rate = ARM_BAUD_38400;
    +
    + port = IO_ADDRESS(0x101F1000);
    + UART_PUT_CR(port, 0);
    +
    + /* Set baud rate */
    + UART_PUT_LCRM(port, ((rate & 0xf00) >> 8));
    + UART_PUT_LCRL(port, (rate & 0xff));
    + UART_PUT_LCRH(port, UART01x_LCRH_WLEN_8 | UART01x_LCRH_FEN);
    + UART_PUT_CR(port, UART01x_CR_UARTEN);
    +
    + return 0;
    +}
    +
    +static void kgdb_serial_putchar(int ch)
    +{
    + unsigned int status;
    +
    + do {
    + status = UART_GET_FR(port);
    + } while (!UART_TX_READY(status));
    +
    + UART_PUT_CHAR(port, ch);
    +}
    +
    +static int kgdb_serial_getchar(void)
    +{
    + unsigned int status;
    + int ch;
    +
    + do {
    + status = UART_GET_FR(port);
    + } while (!UART_RX_DATA(status));
    + ch = UART_GET_CHAR(port);
    + return ch;
    +}
    +
    +static struct uart_port kgdb_amba_port = {
    + .irq = 12,
    + .iobase = 0,
    + .iotype = UPIO_MEM,
    + .membase = (unsigned char *)IO_ADDRESS(0x101F1000),
    +};
    +
    +static irqreturn_t kgdb_interrupt(int irq, void *dev_id, struct pt_regs *regs)
    +{
    + int status = UART_GET_MIS(port);
    +
    + if (irq != kgdb_irq)
    + return IRQ_NONE;
    +
    + if (status & 0x40)
    + breakpoint();
    +
    + return IRQ_HANDLED;
    +}
    +
    +static void __init kgdb_hookup_irq(void)
    +{
    + request_irq(kgdb_irq, kgdb_interrupt, SA_SHIRQ, "GDB-stub",
    + &kgdb_amba_port);
    +}
    +
    +struct kgdb_io kgdb_io_ops = {
    + .init = kgdb_serial_init,
    + .write_char = kgdb_serial_putchar,
    + .read_char = kgdb_serial_getchar,
    + .late_init = kgdb_hookup_irq,
    +};
    Index: linux-2.6.14/arch/arm/mm/extable.c
    ===================================================================
    --- linux-2.6.14.orig/arch/arm/mm/extable.c
    +++ linux-2.6.14/arch/arm/mm/extable.c
    @@ -2,6 +2,7 @@
      * linux/arch/arm/mm/extable.c
      */
     #include <linux/module.h>
    +#include <linux/kgdb.h>
     #include <asm/uaccess.h>
     
     int fixup_exception(struct pt_regs *regs)
    @@ -11,6 +12,12 @@ int fixup_exception(struct pt_regs *regs
             fixup = search_exception_tables(instruction_pointer(regs));
             if (fixup)
                     regs->ARM_pc = fixup->fixup;
    +#ifdef CONFIG_KGDB
    + if (atomic_read(&debugger_active) && kgdb_may_fault)
    + /* Restore our previous state. */
    + kgdb_fault_longjmp(kgdb_fault_jmp_regs);
    + /* Not reached. */
    +#endif
     
             return fixup != NULL;
     }
    Index: linux-2.6.14/drivers/serial/amba-pl011.c
    ===================================================================
    --- linux-2.6.14.orig/drivers/serial/amba-pl011.c
    +++ linux-2.6.14/drivers/serial/amba-pl011.c
    @@ -350,7 +350,7 @@ static int pl011_startup(struct uart_por
             /*
              * Allocate the IRQ
              */
    - retval = request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap);
    + retval = request_irq(uap->port.irq, pl011_int, SA_SHIRQ, "uart-pl011", uap);
             if (retval)
                     goto clk_dis;
     
    Index: linux-2.6.14/include/asm-arm/kgdb.h
    ===================================================================
    --- /dev/null
    +++ linux-2.6.14/include/asm-arm/kgdb.h
    @@ -0,0 +1,87 @@
    +/*
    + * include/asm-arm/kgdb.h
    + *
    + * ARM KGDB support
    + *
    + * Author: Deepak Saxena <dsaxena@mvista.com>
    + *
    + * Copyright (C) 2002 MontaVista Software Inc.
    + *
    + */
    +
    +#ifndef __ASM_KGDB_H__
    +#define __ASM_KGDB_H__
    +
    +#include <linux/config.h>
    +#include <asm/ptrace.h>
    +
    +
    +/*
    + * GDB assumes that we're a user process being debugged, so
    + * it will send us an SWI command to write into memory as the
    + * debug trap. When an SWI occurs, the next instruction addr is
    + * placed into R14_svc before jumping to the vector trap.
    + * This doesn't work for kernel debugging as we are already in SVC
    + * we would loose the kernel's LR, which is a bad thing. This
    + * is bad thing.
    + *
    + * By doing this as an undefined instruction trap, we force a mode
    + * switch from SVC to UND mode, allowing us to save full kernel state.
    + *
    + * We also define a KGDB_COMPILED_BREAK which can be used to compile
    + * in breakpoints. This is important for things like sysrq-G and for
    + * the initial breakpoint from trap_init().
    + *
    + * Note to ARM HW designers: Add real trap support like SH && PPC to
    + * make our lives much much simpler. :)
    + */
    +#define BREAK_INSTR_SIZE 4
    +#define GDB_BREAKINST 0xef9f0001
    +#define KGDB_BREAKINST 0xe7ffdefe
    +#define KGDB_COMPILED_BREAK 0xe7ffdeff
    +#define CACHE_FLUSH_IS_SAFE 1
    +
    +#ifndef __ASSEMBLY__
    +
    +#define BREAKPOINT() asm(".word 0xe7ffdeff")
    +
    +
    +extern void kgdb_handle_bus_error(void);
    +extern int kgdb_fault_expected;
    +
    +/*
    + * From Amit S. Kale:
    + *
    + * In the register packet, words 0-15 are R0 to R10, FP, IP, SP, LR, PC. But
    + * Register 16 isn't cpsr. GDB passes CPSR in word 25. There are 9 words in
    + * between which are unused. Passing only 26 words to gdb is sufficient.
    + * GDB can figure out that floating point registers are not passed.
    + * GDB_MAX_REGS should be 26.
    + */
    +#define GDB_MAX_REGS (26)
    +
    +#define KGDB_MAX_NO_CPUS 1
    +#define BUFMAX 400
    +#define NUMREGBYTES (GDB_MAX_REGS << 2)
    +#define NUMCRITREGBYTES (32 << 2)
    +
    +#define _R0 0
    +#define _R1 1
    +#define _R2 2
    +#define _R3 3
    +#define _R4 4
    +#define _R5 5
    +#define _R6 6
    +#define _R7 7
    +#define _R8 8
    +#define _R9 9
    +#define _R10 10
    +#define _FP 11
    +#define _IP 12
    +#define _SP 13
    +#define _LR 14
    +#define _PC 15
    +#define _CPSR (GDB_MAX_REGS - 1)
    +
    +#endif /* !__ASSEMBLY__ */
    +#endif /* __ASM_KGDB_H__ */
    Index: linux-2.6.14/include/asm-arm/system.h
    ===================================================================
    --- linux-2.6.14.orig/include/asm-arm/system.h
    +++ linux-2.6.14/include/asm-arm/system.h
    @@ -405,6 +405,47 @@ static inline unsigned long __xchg(unsig
             return ret;
     }
     
    +#define __HAVE_ARCH_CMPXCHG 1
    +
    +#include <asm/types.h>
    +
    +static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
    + unsigned long new)
    +{
    + u32 retval;
    + unsigned long flags;
    +
    + local_irq_save(flags);
    + retval = *m;
    + if (retval == old)
    + *m = new;
    + local_irq_restore(flags); /* implies memory barrier */
    +
    + return retval;
    +}
    +
    +/* This function doesn't exist, so you'll get a linker error
    + if something tries to do an invalid cmpxchg(). */
    +extern void __cmpxchg_called_with_bad_pointer(void);
    +
    +static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
    + unsigned long new, int size)
    +{
    + switch (size) {
    + case 4:
    + return __cmpxchg_u32(ptr, old, new);
    + }
    + __cmpxchg_called_with_bad_pointer();
    + return old;
    +}
    +
    +#define cmpxchg(ptr,o,n) \
    + ({ \
    + __typeof__(*(ptr)) _o_ = (o); \
    + __typeof__(*(ptr)) _n_ = (n); \
    + (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
    + (unsigned long)_n_, sizeof(*(ptr))); \
    + })
     #endif /* __ASSEMBLY__ */
     
     #define arch_align_stack(x) (x)
    Index: linux-2.6.14/lib/Kconfig.debug
    ===================================================================
    --- linux-2.6.14.orig/lib/Kconfig.debug
    +++ linux-2.6.14/lib/Kconfig.debug
    @@ -187,7 +187,7 @@ config WANT_EXTRA_DEBUG_INFORMATION
     config KGDB
             bool "KGDB: kernel debugging with remote gdb"
             select WANT_EXTRA_DEBUG_INFORMATION
    - depends on DEBUG_KERNEL && (X86 || MIPS || (SUPERH && !SUPERH64) || IA64 || X86_64 || ((!SMP || BROKEN) && PPC32))
    + depends on DEBUG_KERNEL && (ARM || X86 || MIPS || (SUPERH && !SUPERH64) || IA64 || X86_64 || ((!SMP || BROKEN) && PPC32))
             help
               If you say Y here, it will be possible to remotely debug the
               kernel using gdb. It is strongly suggested that you enable

    -- 
    Tom
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