src/target/xtensa/xtensa_fileio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 /***************************************************************************
   4  *   Xtensa Target File-I/O Support for OpenOCD                            *
   5  *   Copyright (C) 2020-2023 Cadence Design Systems, Inc.                  *
   6  ***************************************************************************/
   7
   8 #ifdef HAVE_CONFIG_H
   9 #include "config.h"
  10 #endif
  11
  12 #include "xtensa_chip.h"
  13 #include "xtensa_fileio.h"
  14 #include "xtensa.h"
  15
  16 #define XTENSA_SYSCALL(x)               XT_INS_BREAK(x, 1, 14)
  17 #define XTENSA_SYSCALL_SZ               3
  18 #define XTENSA_SYSCALL_LEN_MAX  255
  19
  20
  21 int xtensa_fileio_init(struct target *target)
  22 {
  23         char *idmem = malloc(XTENSA_SYSCALL_LEN_MAX + 1);
  24         target->fileio_info = malloc(sizeof(struct gdb_fileio_info));
  25         if (!idmem || !target->fileio_info) {
  26                 LOG_TARGET_ERROR(target, "Out of memory!");
  27                 free(idmem);
  28                 free(target->fileio_info);
  29                 return ERROR_FAIL;
  30         }
  31         target->fileio_info->identifier = idmem;
  32         return ERROR_OK;
  33 }
  34
  35 /**
  36  * Checks for and processes an Xtensa File-IO request.
  37  *
  38  * Return ERROR_OK if request was found and handled; or
  39  * return ERROR_FAIL if no request was detected.
  40  */
  41 int xtensa_fileio_detect_proc(struct target *target)
  42 {
  43         struct xtensa *xtensa = target_to_xtensa(target);
  44         int retval;
  45
  46         xtensa_reg_val_t dbg_cause = xtensa_cause_get(target);
  47         if ((dbg_cause & (DEBUGCAUSE_BI | DEBUGCAUSE_BN)) == 0 || xtensa->halt_request)
  48                 return ERROR_FAIL;
  49
  50         uint8_t brk_insn_buf[sizeof(uint32_t)] = {0};
  51         xtensa_reg_val_t pc = xtensa_reg_get(target, XT_REG_IDX_PC);
  52         retval = target_read_memory(target,
  53                 pc,
  54                 XTENSA_SYSCALL_SZ,
  55                 1,
  56                 (uint8_t *)brk_insn_buf);
  57         if (retval != ERROR_OK) {
  58                 LOG_ERROR("Failed to read break instruction!");
  59                 return ERROR_FAIL;
  60         }
  61         if (buf_get_u32(brk_insn_buf, 0, 32) != XTENSA_SYSCALL(xtensa))
  62                 return ERROR_FAIL;
  63
  64         LOG_TARGET_DEBUG(target, "File-I/O: syscall breakpoint found at 0x%x", pc);
  65         xtensa->proc_syscall = true;
  66         return ERROR_OK;
  67 }
  68
  69 int xtensa_get_gdb_fileio_info(struct target *target, struct gdb_fileio_info *fileio_info)
  70 {
  71         /* fill syscall parameters to file-I/O info */
  72         if (!fileio_info) {
  73                 LOG_ERROR("File-I/O data structure uninitialized");
  74                 return ERROR_FAIL;
  75         }
  76
  77         struct xtensa *xtensa = target_to_xtensa(target);
  78         if (!xtensa->proc_syscall)
  79                 return ERROR_FAIL;
  80
  81         xtensa_reg_val_t syscall = xtensa_reg_get(target, XTENSA_SYSCALL_OP_REG);
  82         xtensa_reg_val_t arg0 = xtensa_reg_get(target, XT_REG_IDX_A6);
  83         xtensa_reg_val_t arg1 = xtensa_reg_get(target, XT_REG_IDX_A3);
  84         xtensa_reg_val_t arg2 = xtensa_reg_get(target, XT_REG_IDX_A4);
  85         xtensa_reg_val_t arg3 = xtensa_reg_get(target, XT_REG_IDX_A5);
  86         int retval = ERROR_OK;
  87
  88         LOG_TARGET_DEBUG(target, "File-I/O: syscall 0x%x 0x%x 0x%x 0x%x 0x%x",
  89                 syscall, arg0, arg1, arg2, arg3);
  90
  91         switch (syscall) {
  92         case XTENSA_SYSCALL_OPEN:
  93                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "open");
  94                 fileio_info->param_1 = arg0;    // pathp
  95                 fileio_info->param_2 = arg3;    // len
  96                 fileio_info->param_3 = arg1;    // flags
  97                 fileio_info->param_4 = arg2;    // mode
  98                 break;
  99         case XTENSA_SYSCALL_CLOSE:
 100                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "close");
 101                 fileio_info->param_1 = arg0;    // fd
 102                 break;
 103         case XTENSA_SYSCALL_READ:
 104                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "read");
 105                 fileio_info->param_1 = arg0;    // fd
 106                 fileio_info->param_2 = arg1;    // bufp
 107                 fileio_info->param_3 = arg2;    // count
 108                 break;
 109         case XTENSA_SYSCALL_WRITE:
 110                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "write");
 111                 fileio_info->param_1 = arg0;    // fd
 112                 fileio_info->param_2 = arg1;    // bufp
 113                 fileio_info->param_3 = arg2;    // count
 114                 break;
 115         case XTENSA_SYSCALL_LSEEK:
 116                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "lseek");
 117                 fileio_info->param_1 = arg0;    // fd
 118                 fileio_info->param_2 = arg1;    // offset
 119                 fileio_info->param_3 = arg2;    // flags
 120                 break;
 121         case XTENSA_SYSCALL_RENAME:
 122                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "rename");
 123                 fileio_info->param_1 = arg0;    // old pathp
 124                 fileio_info->param_2 = arg3;    // old len
 125                 fileio_info->param_3 = arg1;    // new pathp
 126                 fileio_info->param_4 = arg2;    // new len
 127                 break;
 128         case XTENSA_SYSCALL_UNLINK:
 129                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "unlink");
 130                 fileio_info->param_1 = arg0;    // pathnamep
 131                 fileio_info->param_2 = arg1;    // len
 132                 break;
 133         case XTENSA_SYSCALL_STAT:
 134                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "stat");
 135                 fileio_info->param_1 = arg0;    // pathnamep
 136                 fileio_info->param_2 = arg2;    // len
 137                 fileio_info->param_3 = arg1;    // bufp
 138                 break;
 139         case XTENSA_SYSCALL_FSTAT:
 140                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "fstat");
 141                 fileio_info->param_1 = arg0;    // fd
 142                 fileio_info->param_2 = arg1;    // bufp
 143                 break;
 144         case XTENSA_SYSCALL_GETTIMEOFDAY:
 145                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "gettimeofday");
 146                 fileio_info->param_1 = arg0;    // tvp
 147                 fileio_info->param_2 = arg1;    // tzp
 148                 break;
 149         case XTENSA_SYSCALL_ISATTY:
 150                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "isatty");
 151                 fileio_info->param_1 = arg0;    // fd
 152                 break;
 153         case XTENSA_SYSCALL_SYSTEM:
 154                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "system");
 155                 fileio_info->param_1 = arg0;    // cmdp
 156                 fileio_info->param_2 = arg1;    // len
 157                 break;
 158         default:
 159                 snprintf(fileio_info->identifier, XTENSA_SYSCALL_LEN_MAX, "unknown");
 160                 LOG_TARGET_DEBUG(target, "File-I/O: syscall unknown (%d), pc=0x%08X",
 161                         syscall, xtensa_reg_get(target, XT_REG_IDX_PC));
 162                 LOG_INFO("File-I/O: syscall unknown (%d), pc=0x%08X",
 163                         syscall, xtensa_reg_get(target, XT_REG_IDX_PC));
 164                 retval = ERROR_FAIL;
 165                 break;
 166         }
 167
 168         return retval;
 169 }
 170
 171 int xtensa_gdb_fileio_end(struct target *target, int retcode, int fileio_errno, bool ctrl_c)
 172 {
 173         struct xtensa *xtensa = target_to_xtensa(target);
 174         if (!xtensa->proc_syscall)
 175                 return ERROR_FAIL;
 176
 177         LOG_TARGET_DEBUG(target, "File-I/O: syscall return code: 0x%x, errno: 0x%x , ctrl_c: %s",
 178                 retcode, fileio_errno, ctrl_c ? "true" : "false");
 179
 180         /* If interrupt was requested before FIO completion (ERRNO==4), halt and repeat
 181          * syscall. Otherwise, set File-I/O Ax and underlying ARx registers, increment PC.
 182          * NOTE: sporadic cases of ((ERRNO==4) && !ctrl_c) were observed; most have ctrl_c.
 183          */
 184         if (fileio_errno != 4) {
 185                 xtensa_reg_set_deep_relgen(target, XTENSA_SYSCALL_RETVAL_REG, retcode);
 186                 xtensa_reg_set_deep_relgen(target, XTENSA_SYSCALL_ERRNO_REG, fileio_errno);
 187
 188                 xtensa_reg_val_t pc = xtensa_reg_get(target, XT_REG_IDX_PC);
 189                 xtensa_reg_set(target, XT_REG_IDX_PC, pc + XTENSA_SYSCALL_SZ);
 190         }
 191
 192         xtensa->proc_syscall = false;
 193         xtensa->halt_request = true;
 194         return ctrl_c ? ERROR_FAIL : ERROR_OK;
 195 }