diff options
Diffstat (limited to 'arch/nios2/kernel/kgdb.c')
| -rw-r--r-- | arch/nios2/kernel/kgdb.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/arch/nios2/kernel/kgdb.c b/arch/nios2/kernel/kgdb.c new file mode 100644 index 000000000..d0963fcb1 --- /dev/null +++ b/arch/nios2/kernel/kgdb.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Nios2 KGDB support + * + * Copyright (C) 2015 Altera Corporation + * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> + * + * Based on the code posted by Kazuyasu on the Altera Forum at: + * http://www.alteraforum.com/forum/showpost.php?p=77003&postcount=20 + */ +#include <linux/ptrace.h> +#include <linux/kgdb.h> +#include <linux/kdebug.h> +#include <linux/io.h> + +static int wait_for_remote_debugger; + +struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = +{ + { "zero", GDB_SIZEOF_REG, -1 }, + { "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, r1) }, + { "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r2) }, + { "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r3) }, + { "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r4) }, + { "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r5) }, + { "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r6) }, + { "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r7) }, + { "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r8) }, + { "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r9) }, + { "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10) }, + { "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11) }, + { "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12) }, + { "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13) }, + { "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14) }, + { "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15) }, + { "r16", GDB_SIZEOF_REG, -1 }, + { "r17", GDB_SIZEOF_REG, -1 }, + { "r18", GDB_SIZEOF_REG, -1 }, + { "r19", GDB_SIZEOF_REG, -1 }, + { "r20", GDB_SIZEOF_REG, -1 }, + { "r21", GDB_SIZEOF_REG, -1 }, + { "r22", GDB_SIZEOF_REG, -1 }, + { "r23", GDB_SIZEOF_REG, -1 }, + { "et", GDB_SIZEOF_REG, -1 }, + { "bt", GDB_SIZEOF_REG, -1 }, + { "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp) }, + { "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp) }, + { "fp", GDB_SIZEOF_REG, offsetof(struct pt_regs, fp) }, + { "ea", GDB_SIZEOF_REG, -1 }, + { "ba", GDB_SIZEOF_REG, -1 }, + { "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, ra) }, + { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, ea) }, + { "status", GDB_SIZEOF_REG, -1 }, + { "estatus", GDB_SIZEOF_REG, offsetof(struct pt_regs, estatus) }, + { "bstatus", GDB_SIZEOF_REG, -1 }, + { "ienable", GDB_SIZEOF_REG, -1 }, + { "ipending", GDB_SIZEOF_REG, -1}, + { "cpuid", GDB_SIZEOF_REG, -1 }, + { "ctl6", GDB_SIZEOF_REG, -1 }, + { "exception", GDB_SIZEOF_REG, -1 }, + { "pteaddr", GDB_SIZEOF_REG, -1 }, + { "tlbacc", GDB_SIZEOF_REG, -1 }, + { "tlbmisc", GDB_SIZEOF_REG, -1 }, + { "eccinj", GDB_SIZEOF_REG, -1 }, + { "badaddr", GDB_SIZEOF_REG, -1 }, + { "config", GDB_SIZEOF_REG, -1 }, + { "mpubase", GDB_SIZEOF_REG, -1 }, + { "mpuacc", GDB_SIZEOF_REG, -1 }, +}; + +char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) +{ + if (regno >= DBG_MAX_REG_NUM || regno < 0) + return NULL; + + if (dbg_reg_def[regno].offset != -1) + memcpy(mem, (void *)regs + dbg_reg_def[regno].offset, + dbg_reg_def[regno].size); + else + memset(mem, 0, dbg_reg_def[regno].size); + + return dbg_reg_def[regno].name; +} + +int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) +{ + if (regno >= DBG_MAX_REG_NUM || regno < 0) + return -EINVAL; + + if (dbg_reg_def[regno].offset != -1) + memcpy((void *)regs + dbg_reg_def[regno].offset, mem, + dbg_reg_def[regno].size); + + return 0; +} + +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) +{ + memset((char *)gdb_regs, 0, NUMREGBYTES); + gdb_regs[GDB_SP] = p->thread.kregs->sp; + gdb_regs[GDB_PC] = p->thread.kregs->ea; +} + +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) +{ + regs->ea = pc; +} + +int kgdb_arch_handle_exception(int vector, int signo, int err_code, + char *remcom_in_buffer, char *remcom_out_buffer, + struct pt_regs *regs) +{ + char *ptr; + unsigned long addr; + + switch (remcom_in_buffer[0]) { + case 's': + case 'c': + /* handle the optional parameters */ + ptr = &remcom_in_buffer[1]; + if (kgdb_hex2long(&ptr, &addr)) + regs->ea = addr; + + return 0; + } + + return -1; /* this means that we do not want to exit from the handler */ +} + +asmlinkage void kgdb_breakpoint_c(struct pt_regs *regs) +{ + /* + * The breakpoint entry code has moved the PC on by 4 bytes, so we must + * move it back. This could be done on the host but we do it here + */ + if (!wait_for_remote_debugger) + regs->ea -= 4; + else /* pass the first trap 30 code */ + wait_for_remote_debugger = 0; + + kgdb_handle_exception(30, SIGTRAP, 0, regs); +} + +int kgdb_arch_init(void) +{ + wait_for_remote_debugger = 1; + return 0; +} + +void kgdb_arch_exit(void) +{ + /* Nothing to do */ +} + +const struct kgdb_arch arch_kgdb_ops = { + /* Breakpoint instruction: trap 30 */ + .gdb_bpt_instr = { 0xba, 0x6f, 0x3b, 0x00 }, +}; |