// Copyright 2010-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "esp_attr.h"
#include "esp_err.h"
#include "esp_log.h"
#include "esp32/ulp.h"
#include "soc/soc.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/sens_reg.h"
#include "sdkconfig.h"
static const char* TAG = "ulp";
typedef struct {
uint32_t label : 16;
uint32_t addr : 11;
uint32_t unused : 1;
uint32_t type : 4;
} reloc_info_t;
#define RELOC_TYPE_LABEL 0
#define RELOC_TYPE_BRANCH 1
/* This record means: there is a label at address
* insn_addr, with number label_num.
*/
#define RELOC_INFO_LABEL(label_num, insn_addr) (reloc_info_t) { \
.label = label_num, \
.addr = insn_addr, \
.unused = 0, \
.type = RELOC_TYPE_LABEL }
/* This record means: there is a branch instruction at
* insn_addr, it needs to be changed to point to address
* of label label_num.
*/
#define RELOC_INFO_BRANCH(label_num, insn_addr) (reloc_info_t) { \
.label = label_num, \
.addr = insn_addr, \
.unused = 0, \
.type = RELOC_TYPE_BRANCH }
/* Processing branch and label macros involves four steps:
*
* 1. Iterate over program and count all instructions
* with "macro" opcode. Allocate relocations array
* with number of entries equal to number of macro
* instructions.
*
* 2. Remove all fake instructions with "macro" opcode
* and record their locations into relocations array.
* Removal is done using two pointers. Instructions
* are read from read_ptr, and written to write_ptr.
* When a macro instruction is encountered,
* its contents are recorded into the appropriate
* table, and then read_ptr is advanced again.
* When a real instruction is encountered, it is
* read via read_ptr and written to write_ptr.
* In the end, all macro instructions are removed,
* size of the program (expressed in words) is
* reduced by the total number of macro instructions
* which were present.
*
* 3. Sort relocations array by label number, and then
* by type ("label" or "branch") if label numbers
* match. This is done to simplify lookup on the next
* step.
*
* 4. Iterate over entries of relocations table.
* For each label number, label entry comes first
* because the array was sorted at the previous step.
* Label address is recorded, and all subsequent
* "branch" entries which point to the same label number
* are processed. For each branch entry, correct offset
* or absolute address is calculated, depending on branch
* type, and written into the appropriate field of
* the instruction.
*
*/
static esp_err_t do_single_reloc(ulp_insn_t* program, uint32_t load_addr,
reloc_info_t label_info, reloc_info_t branch_info)
{
size_t insn_offset = branch_info.addr - load_addr;
ulp_insn_t* insn = &program[insn_offset];
// B and BX have the same layout of opcode/sub_opcode fields,
// and share the same opcode
assert(insn->b.opcode == OPCODE_BRANCH
&& "branch macro was applied to a non-branch instruction");
switch (insn->b.sub_opcode) {
case SUB_OPCODE_B: {
int32_t offset = ((int32_t) label_info.addr) - ((int32_t) branch_info.addr);
uint32_t abs_offset = abs(offset);
uint32_t sign = (offset >= 0) ? 0 : 1;
if (abs_offset > 127) {
ESP_LOGW(TAG, "target out of range: branch from %x to %x",
branch_info.addr, label_info.addr);
return ESP_ERR_ULP_BRANCH_OUT_OF_RANGE;
}
insn->b.offset = abs_offset;
insn->b.sign = sign;
break;
}
case SUB_OPCODE_BX: {
assert(insn->bx.reg == 0 &&
"relocation applied to a jump with offset in register");
insn->bx.addr = label_info.addr;
break;
}
default:
assert(false && "unexpected sub-opcode");
}
return ESP_OK;
}
esp_err_t ulp_process_macros_and_load(uint32_t load_addr, const ulp_insn_t* program, size_t* psize)
{
const ulp_insn_t* read_ptr = program;
const ulp_insn_t* end = program + *psize;
size_t macro_count = 0;
// step 1: calculate number of macros
while (read_ptr < end) {
ulp_insn_t r_insn = *read_ptr;
if (r_insn.macro.opcode == OPCODE_MACRO) {
++macro_count;
}
++read_ptr;
}
size_t real_program_size = *psize - macro_count;
const size_t ulp_mem_end = CONFIG_ULP_COPROC_RESERVE_MEM / sizeof(ulp_insn_t);
if (load_addr > ulp_mem_end) {
ESP_LOGW(TAG, "invalid load address %x, max is %x",
load_addr, ulp_mem_end);
return ESP_ERR_ULP_INVALID_LOAD_ADDR;
}
if (real_program_size + load_addr > ulp_mem_end) {
ESP_LOGE(TAG, "program too big: %d words, max is %d words",
real_program_size, ulp_mem_end);
return ESP_ERR_ULP_SIZE_TOO_BIG;
}
// If no macros found, copy the program and return.
if (macro_count == 0) {
memcpy(((ulp_insn_t*) RTC_SLOW_MEM) + load_addr, program, *psize * sizeof(ulp_insn_t));
return ESP_OK;
}
reloc_info_t* reloc_info =
(reloc_info_t*) malloc(sizeof(reloc_info_t) * macro_count);
if (reloc_info == NULL) {
return ESP_ERR_NO_MEM;
}
// step 2: record macros into reloc_info array
// and remove them from then program
read_ptr = program;
ulp_insn_t* output_program = ((ulp_insn_t*) RTC_SLOW_MEM) + load_addr;
ulp_insn_t* write_ptr = output_program;
uint32_t cur_insn_addr = load_addr;
reloc_info_t* cur_reloc = reloc_info;
while (read_ptr < end) {
ulp_insn_t r_insn = *read_ptr;
if (r_insn.macro.opcode == OPCODE_MACRO) {
switch(r_insn.macro.sub_opcode) {
case SUB_OPCODE_MACRO_LABEL:
*cur_reloc = RELOC_INFO_LABEL(r_insn.macro.label,
cur_insn_addr);
break;
case SUB_OPCODE_MACRO_BRANCH:
*cur_reloc = RELOC_INFO_BRANCH(r_insn.macro.label,
cur_insn_addr);
break;
default:
assert(0 && "invalid sub_opcode for macro insn");
}
++read_ptr;
assert(read_ptr != end && "program can not end with macro insn");
++cur_reloc;
} else {
// normal instruction (not a macro)
*write_ptr = *read_ptr;
++read_ptr;
++write_ptr;
++cur_insn_addr;
}
}
// step 3: sort relocations array
int reloc_sort_func(const void* p_lhs, const void* p_rhs) {
const reloc_info_t lhs = *(const reloc_info_t*) p_lhs;
const reloc_info_t rhs = *(const reloc_info_t*) p_rhs;
if (lhs.label < rhs.label) {
return -1;
} else if (lhs.label > rhs.label) {
return 1;
}
// label numbers are equal
if (lhs.type < rhs.type) {
return -1;
} else if (lhs.type > rhs.type) {
return 1;
}
// both label number and type are equal
return 0;
}
qsort(reloc_info, macro_count, sizeof(reloc_info_t),
reloc_sort_func);
// step 4: walk relocations array and fix instructions
reloc_info_t* reloc_end = reloc_info + macro_count;
cur_reloc = reloc_info;
while(cur_reloc < reloc_end) {
reloc_info_t label_info = *cur_reloc;
assert(label_info.type == RELOC_TYPE_LABEL);
++cur_reloc;
while (cur_reloc < reloc_end) {
if (cur_reloc->type == RELOC_TYPE_LABEL) {
if(cur_reloc->label == label_info.label) {
ESP_LOGE(TAG, "duplicate label definition: %d",
label_info.label);
free(reloc_info);
return ESP_ERR_ULP_DUPLICATE_LABEL;
}
break;
}
if (cur_reloc->label != label_info.label) {
ESP_LOGE(TAG, "branch to an inexistent label: %d",
cur_reloc->label);
free(reloc_info);
return ESP_ERR_ULP_UNDEFINED_LABEL;
}
esp_err_t rc = do_single_reloc(output_program, load_addr,
label_info, *cur_reloc);
if (rc != ESP_OK) {
free(reloc_info);
return rc;
}
++cur_reloc;
}
}
free(reloc_info);
*psize = real_program_size;
return ESP_OK;
}