/**
* Marlin 3D Printer Firmware
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
*
* 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 3 of the License, or
* (at your option) 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, see <http://www.gnu.org/licenses/>.
*
*/
/**
* M100 Free Memory Watcher
*
* This code watches the free memory block between the bottom of the heap and the top of the stack.
* This memory block is initialized and watched via the M100 command.
*
* M100 I Initializes the free memory block and prints vitals statistics about the area
*
* M100 F Identifies how much of the free memory block remains free and unused. It also
* detects and reports any corruption within the free memory block that may have
* happened due to errant firmware.
*
* M100 D Does a hex display of the free memory block along with a flag for any errant
* data that does not match the expected value.
*
* M100 C x Corrupts x locations within the free memory block. This is useful to check the
* correctness of the M100 F and M100 D commands.
*
* Initial version by Roxy-3D
*/
#define M100_FREE_MEMORY_DUMPER // Enable for the `M110 D` Dump sub-command
#define M100_FREE_MEMORY_CORRUPTOR // Enable for the `M100 C` Corrupt sub-command
#include "MarlinConfig.h"
#if ENABLED(M100_FREE_MEMORY_WATCHER)
#define TEST_BYTE 0xE5
extern char* __brkval;
extern size_t __heap_start, __heap_end, __flp;
extern char __bss_end;
#include "Marlin.h"
#include "hex_print_routines.h"
//
// Utility functions
//
#define END_OF_HEAP() (__brkval ? __brkval : &__bss_end)
// Location of a variable on its stack frame. Returns a value above
// the stack (once the function returns to the caller).
char* top_of_stack() {
char x;
return &x + 1; // x is pulled on return;
}
// Count the number of test bytes at the specified location.
int16_t count_test_bytes(const char * const ptr) {
for (uint16_t i = 0; i < 32000; i++)
if (ptr[i] != TEST_BYTE)
return i - 1;
return -1;
}
// Return a count of free memory blocks.
uint16_t free_memory_is_corrupted(char * const ptr, const uint16_t size) {
// Find the longest block of test bytes in the given buffer
uint16_t block_cnt = 0;
for (uint16_t i = 0; i < size; i++) {
if (ptr[i] == TEST_BYTE) {
const uint16_t j = count_test_bytes(ptr + i);
if (j > 8) {
//SERIAL_ECHOPAIR("Found ", j);
//SERIAL_ECHOLNPAIR(" bytes free at 0x", hex_word((uint16_t)ptr + i));
i += j;
block_cnt++;
}
}
}
//if (block_cnt > 1) {
// SERIAL_ECHOLNPGM("\nMemory Corruption detected in free memory area.");
// SERIAL_ECHOLNPAIR("\nLargest free block is ", max_cnt);
//}
return block_cnt;
}
//
// M100 sub-commands
//
#if ENABLED(M100_FREE_MEMORY_DUMPER)
/**
* M100 D
* Dump the free memory block from __brkval to the stack pointer.
* malloc() eats memory from the start of the block and the stack grows
* up from the bottom of the block. Solid test bytes indicate nothing has
* used that memory yet. There should not be anything but test bytes within
* the block. If so, it may indicate memory corruption due to a bad pointer.
* Unexpected bytes are flagged in the right column.
*/
void dump_free_memory(char *ptr, char *sp) {
//
// Start and end the dump on a nice 16 byte boundary
// (even though the values are not 16-byte aligned).
//
ptr = (char*)((uint16_t)ptr & 0xFFF0); // Align to 16-byte boundary
sp = (char*)((uint16_t)sp | 0x000F); // Align sp to the 15th byte (at or above sp)
// Dump command main loop
while (ptr < sp) {
print_hex_word((uint16_t)ptr); // Print the address
SERIAL_CHAR(':');
for (uint8_t i = 0; i < 16; i++) { // and 16 data bytes
if (i == 8) SERIAL_CHAR('-');
print_hex_byte(ptr[i]);
SERIAL_CHAR(' ');
}
SERIAL_CHAR('|'); // Point out non test bytes
for (uint8_t i = 0; i < 16; i++)
SERIAL_CHAR(ptr[i] == TEST_BYTE ? ' ' : '?');
SERIAL_EOL;
ptr += 16;
idle();
}
}
#endif // M100_FREE_MEMORY_DUMPER
/**
* M100 F
* Return the number of free bytes in the memory pool,
* with other vital statistics defining the pool.
*/
void free_memory_pool_report(const char * const ptr, const uint16_t size) {
int16_t max_cnt = -1;
uint16_t block_cnt = 0;
char *max_addr = NULL;
// Find the longest block of test bytes in the buffer
for (uint16_t i = 0; i < size; i++) {
char * const addr = ptr + i;
if (*addr == TEST_BYTE) {
const uint16_t j = count_test_bytes(addr);
if (j > 8) {
SERIAL_ECHOPAIR("Found ", j);
SERIAL_ECHOLNPAIR(" bytes free at 0x", hex_word((uint16_t)addr));
if (j > max_cnt) {
max_cnt = j;
max_addr = addr;
}
i += j;
block_cnt++;
}
}
}
if (block_cnt > 1) {
SERIAL_ECHOLNPGM("\nMemory Corruption detected in free memory area.");
SERIAL_ECHOPAIR("\nLargest free block is ", max_cnt);
SERIAL_ECHOLNPAIR(" bytes at 0x", hex_word((uint16_t)max_addr));
}
SERIAL_ECHOLNPAIR("free_memory_is_corrupted() = ", free_memory_is_corrupted(ptr, size));
}
#if ENABLED(M100_FREE_MEMORY_CORRUPTOR)
/**
* M100 C<num>
* Corrupt <num> locations in the free memory pool and report the corrupt addresses.
* This is useful to check the correctness of the M100 D and the M100 F commands.
*/
void corrupt_free_memory(char *ptr, const uint16_t size) {
if (code_seen('C')) {
ptr += 8;
const uint16_t near_top = top_of_stack() - ptr - 250, // -250 to avoid interrupt activity that's altered the stack.
j = near_top / (size + 1);
SERIAL_ECHOLNPGM("Corrupting free memory block.\n");
for (uint16_t i = 1; i <= size; i++) {
char * const addr = ptr + i * j;
*addr = i;
SERIAL_ECHOPAIR("\nCorrupting address: 0x", hex_word((uint16_t)addr));
}
SERIAL_EOL;
}
}
#endif // M100_FREE_MEMORY_CORRUPTOR
/**
* M100 I
* Init memory for the M100 tests. (Automatically applied on the first M100.)
*/
void init_free_memory(char *ptr, int16_t size) {
SERIAL_ECHOLNPGM("Initializing free memory block.\n\n");
size -= 250; // -250 to avoid interrupt activity that's altered the stack.
if (size < 0) return;
ptr += 8;
memset(ptr, TEST_BYTE, size);
SERIAL_ECHO(size);
SERIAL_ECHOLNPGM(" bytes of memory initialized.\n");
for (uint16_t i = 0; i < size; i++) {
if (ptr[i] != TEST_BYTE) {
SERIAL_ECHOPAIR("? address : 0x", hex_word((uint16_t)ptr + i));
SERIAL_ECHOPAIR("=", hex_byte(ptr[i]));
SERIAL_EOL; SERIAL_EOL;
}
}
}
/**
* M100: Free Memory Check
*/
void gcode_M100() {
SERIAL_ECHOPAIR("\n__brkval : 0x", hex_word((uint16_t)__brkval));
SERIAL_ECHOPAIR("\n__bss_end : 0x", hex_word((uint16_t)&__bss_end));
char *ptr = END_OF_HEAP(), *sp = top_of_stack();
SERIAL_ECHOPAIR("\nstart of free space : 0x", hex_word((uint16_t)ptr));
SERIAL_ECHOLNPAIR("\nStack Pointer : 0x", hex_word((uint16_t)sp));
// Always init on the first invocation of M100
static bool m100_not_initialized = true;
if (m100_not_initialized || code_seen('I')) {
m100_not_initialized = false;
init_free_memory(ptr, sp - ptr);
}
#if ENABLED(M100_FREE_MEMORY_DUMPER)
if (code_seen('D'))
return dump_free_memory(ptr, sp);
#endif
if (code_seen('F'))
return free_memory_pool_report(ptr, sp - ptr);
#if ENABLED(M100_FREE_MEMORY_CORRUPTOR)
if (code_seen('C'))
return corrupt_free_memory(ptr, code_value_int());
#endif
}
#endif // M100_FREE_MEMORY_WATCHER