//-----------------------------------------------------------------------------
// Copyright (C) 2010 Hector Martin "marcan" <marcan@marcansoft.com>
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// ELF file flasher
//-----------------------------------------------------------------------------
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "proxusb.h"
#include "flash.h"
#include "elf.h"
#include "proxendian.h"
#include "sleep.h"
#define FLASH_START 0x100000
#define FLASH_SIZE (256*1024)
#define FLASH_END (FLASH_START + FLASH_SIZE)
#define BOOTLOADER_SIZE 0x2000
#define BOOTLOADER_END (FLASH_START + BOOTLOADER_SIZE)
#define BLOCK_SIZE 0x100
static const uint8_t elf_ident[] = {
0x7f, 'E', 'L', 'F',
ELFCLASS32,
ELFDATA2LSB,
EV_CURRENT
};
// Turn PHDRs into flasher segments, checking for PHDR sanity and merging adjacent
// unaligned segments if needed
static int build_segs_from_phdrs(flash_file_t *ctx, FILE *fd, Elf32_Phdr *phdrs, int num_phdrs) {
Elf32_Phdr *phdr = phdrs;
flash_seg_t *seg;
uint32_t last_end = 0;
ctx->segments = calloc(sizeof(flash_seg_t) * num_phdrs, sizeof(uint8_t));
if (!ctx->segments) {
fprintf(stderr, "Out of memory\n");
return -1;
}
ctx->num_segs = 0;
seg = ctx->segments;
fprintf(stdout, "Loading usable ELF segments:\n");
for (int i = 0; i < num_phdrs; i++) {
if (le32(phdr->p_type) != PT_LOAD) {
phdr++;
continue;
}
uint32_t vaddr = le32(phdr->p_vaddr);
uint32_t paddr = le32(phdr->p_paddr);
uint32_t filesz = le32(phdr->p_filesz);
uint32_t memsz = le32(phdr->p_memsz);
uint32_t offset = le32(phdr->p_offset);
uint32_t flags = le32(phdr->p_flags);
if (!filesz) {
phdr++;
continue;
}
fprintf(stdout, "%d: V 0x%08x P 0x%08x (0x%08x->0x%08x) [%c%c%c] @0x%x\n",
i, vaddr, paddr, filesz, memsz,
(flags & PF_R) ? 'R' : ' ',
(flags & PF_W) ? 'W' : ' ',
(flags & PF_X) ? 'X' : ' ',
offset);
if (filesz != memsz) {
fprintf(stderr, "Error: PHDR file size does not equal memory size\n"
"(DATA+BSS PHDRs do not make sense on ROM platforms!)\n");
return -1;
}
if (paddr < last_end) {
fprintf(stderr, "Error: PHDRs not sorted or overlap\n");
return -1;
}
if (paddr < FLASH_START || (paddr + filesz) > FLASH_END) {
fprintf(stderr, "Error: PHDR is not contained in Flash\n");
return -1;
}
if (vaddr >= FLASH_START && vaddr < FLASH_END && (flags & PF_W)) {
fprintf(stderr, "Error: Flash VMA segment is writable\n");
return -1;
}
uint8_t *data;
// make extra space if we need to move the data forward
data = calloc(filesz + BLOCK_SIZE, sizeof(uint8_t));
if (!data) {
fprintf(stderr, "Error: Out of memory\n");
return -1;
}
if (fseek(fd, offset, SEEK_SET) < 0 || fread(data, 1, filesz, fd) != filesz) {
fprintf(stderr, "Error while reading PHDR payload\n");
free(data);
return -1;
}
uint32_t block_offset = paddr & (BLOCK_SIZE - 1);
if (block_offset) {
if (ctx->num_segs) {
flash_seg_t *prev_seg = seg - 1;
uint32_t this_end = paddr + filesz;
uint32_t this_firstblock = paddr & ~(BLOCK_SIZE - 1);
uint32_t prev_lastblock = (last_end - 1) & ~(BLOCK_SIZE - 1);
if (this_firstblock == prev_lastblock) {
uint32_t new_length = this_end - prev_seg->start;
uint32_t this_offset = paddr - prev_seg->start;
uint32_t hole = this_offset - prev_seg->length;
uint8_t *new_data = calloc(new_length, sizeof(uint8_t));
if (!new_data) {
fprintf(stderr, "Error: Out of memory\n");
free(data);
return -1;
}
memset(new_data, 0xff, new_length);
memcpy(new_data, prev_seg->data, prev_seg->length);
memcpy(new_data + this_offset, data, filesz);
fprintf(stderr, "Note: Extending previous segment from 0x%x to 0x%x bytes\n",
prev_seg->length, new_length);
if (hole)
fprintf(stderr, "Note: 0x%x-byte hole created\n", hole);
free(data);
free(prev_seg->data);
prev_seg->data = new_data;
prev_seg->length = new_length;
last_end = this_end;
phdr++;
continue;
}
}
fprintf(stderr, "Warning: segment does not begin on a block boundary, will pad\n");
memmove(data + block_offset, data, filesz);
memset(data, 0xFF, block_offset);
filesz += block_offset;
paddr -= block_offset;
}
seg->data = data;
seg->start = paddr;
seg->length = filesz;
seg++;
ctx->num_segs++;
last_end = paddr + filesz;
phdr++;
}
return 0;
}
// Sanity check segments and check for bootloader writes
static int check_segs(flash_file_t *ctx, int can_write_bl) {
for (int i = 0; i < ctx->num_segs; i++) {
flash_seg_t *seg = &ctx->segments[i];
if (seg->start & (BLOCK_SIZE - 1)) {
fprintf(stderr, "Error: Segment is not aligned\n");
return -1;
}
if (seg->start < FLASH_START) {
fprintf(stderr, "Error: Segment is outside of flash bounds\n");
return -1;
}
if (seg->start + seg->length > FLASH_END) {
fprintf(stderr, "Error: Segment is outside of flash bounds\n");
return -1;
}
if (!can_write_bl && seg->start < BOOTLOADER_END) {
fprintf(stderr, "Attempted to write bootloader but bootloader writes are not enabled\n");
return -1;
}
}
return 0;
}
// Load an ELF file and prepare it for flashing
int flash_load(flash_file_t *ctx, const char *name, int can_write_bl) {
FILE *fd;
Elf32_Ehdr ehdr;
Elf32_Phdr *phdrs = NULL;
int num_phdrs;
int res;
fd = fopen(name, "rb");
if (!fd) {
fprintf(stderr, "Could not open file '%s': ", name);
perror(NULL);
goto fail;
}
fprintf(stderr, "Loading ELF file '%s'...\n", name);
if (fread(&ehdr, sizeof(ehdr), 1, fd) != 1) {
fprintf(stderr, "Error while reading ELF file header\n");
goto fail;
}
if (memcmp(ehdr.e_ident, elf_ident, sizeof(elf_ident))
|| le32(ehdr.e_version) != 1) {
fprintf(stderr, "Not an ELF file or wrong ELF type\n");
goto fail;
}
if (le16(ehdr.e_type) != ET_EXEC) {
fprintf(stderr, "ELF is not executable\n");
goto fail;
}
if (le16(ehdr.e_machine) != EM_ARM) {
fprintf(stderr, "Wrong ELF architecture\n");
goto fail;
}
if (!ehdr.e_phnum || !ehdr.e_phoff) {
fprintf(stderr, "ELF has no PHDRs\n");
goto fail;
}
if (le16(ehdr.e_phentsize) != sizeof(Elf32_Phdr)) {
// could be a structure padding issue...
fprintf(stderr, "Either the ELF file or this code is made of fail\n");
goto fail;
}
num_phdrs = le16(ehdr.e_phnum);
phdrs = calloc(le16(ehdr.e_phnum) * sizeof(Elf32_Phdr), sizeof(uint8_t));
if (!phdrs) {
fprintf(stderr, "Out of memory\n");
goto fail;
}
if (fseek(fd, le32(ehdr.e_phoff), SEEK_SET) < 0) {
fprintf(stderr, "Error while reading ELF PHDRs\n");
goto fail;
}
if (fread(phdrs, sizeof(Elf32_Phdr), num_phdrs, fd) != num_phdrs) {
fprintf(stderr, "Error while reading ELF PHDRs\n");
goto fail;
}
res = build_segs_from_phdrs(ctx, fd, phdrs, num_phdrs);
if (res < 0)
goto fail;
res = check_segs(ctx, can_write_bl);
if (res < 0)
goto fail;
free(phdrs);
fclose(fd);
ctx->filename = name;
return 0;
fail:
if (phdrs)
free(phdrs);
if (fd)
fclose(fd);
flash_free(ctx);
return -1;
}
// Get the state of the proxmark, backwards compatible
static int get_proxmark_state(uint32_t *state) {
SendCommandBL(CMD_DEVICE_INFO, 0, 0, 0, NULL, 0);
PacketResponseOLD resp;
ReceiveCommand(&resp);
// Three outcomes:
// 1. The old bootrom code will ignore CMD_DEVICE_INFO, but respond with an ACK
// 2. The old os code will respond with CMD_DEBUG_PRINT_STRING and "unknown command"
// 3. The new bootrom and os codes will respond with CMD_DEVICE_INFO and flags
switch (resp.cmd) {
case CMD_ACK:
*state = DEVICE_INFO_FLAG_CURRENT_MODE_BOOTROM;
break;
case CMD_DEBUG_PRINT_STRING:
*state = DEVICE_INFO_FLAG_CURRENT_MODE_OS;
break;
case CMD_DEVICE_INFO:
*state = resp.arg[0];
break;
default:
fprintf(stderr, "Error: Couldn't get Proxmark3 state, bad response type: 0x%04x\n", resp.cmd);
return -1;
break;
}
return 0;
}
// Enter the bootloader to be able to start flashing
static int enter_bootloader(void) {
uint32_t state;
if (get_proxmark_state(&state) < 0)
return -1;
if (state & DEVICE_INFO_FLAG_CURRENT_MODE_BOOTROM) {
/* Already in flash state, we're done. */
return 0;
}
if (state & DEVICE_INFO_FLAG_CURRENT_MODE_OS) {
fprintf(stderr, "Entering bootloader...\n");
if ((state & DEVICE_INFO_FLAG_BOOTROM_PRESENT)
&& (state & DEVICE_INFO_FLAG_OSIMAGE_PRESENT)) {
// New style handover: Send CMD_START_FLASH, which will reset the board
// and enter the bootrom on the next boot.
SendCommandBL(CMD_START_FLASH, 0, 0, 0, NULL, 0);
fprintf(stderr, "(Press and release the button only to abort)\n");
} else {
// Old style handover: Ask the user to press the button, then reset the board
SendCommandBL(CMD_HARDWARE_RESET, 0, 0, 0, NULL, 0);
fprintf(stderr, "Press and hold down button NOW if your bootloader requires it.\n");
}
fprintf(stderr, "Waiting for Proxmark3 to reappear on USB...");
CloseProxmark();
msleep(1000);
while (!OpenProxmark(0)) {
msleep(1000);
fprintf(stderr, ".");
fflush(stdout);
}
fprintf(stderr, " Found.\n");
return 0;
}
fprintf(stderr, "Error: Unknown Proxmark3 mode\n");
return -1;
}
static int wait_for_ack(void) {
PacketResponseOLD ack;
ReceiveCommand(&ack);
if (ack.cmd != CMD_ACK) {
printf("Error: Unexpected reply 0x%04x (expected ACK)\n", ack.cmd);
return -1;
}
return 0;
}
// Go into flashing mode
int flash_start_flashing(int enable_bl_writes) {
uint32_t state;
if (enter_bootloader() < 0)
return -1;
if (get_proxmark_state(&state) < 0)
return -1;
if (state & DEVICE_INFO_FLAG_UNDERSTANDS_START_FLASH) {
// This command is stupid. Why the heck does it care which area we're
// flashing, as long as it's not the bootloader area? The mind boggles.
if (enable_bl_writes) {
SendCommandBL(CMD_START_FLASH, FLASH_START, FLASH_END, START_FLASH_MAGIC, NULL, 0);
} else {
SendCommandBL(CMD_START_FLASH, BOOTLOADER_END, FLASH_END, 0, NULL, 0);
}
return wait_for_ack();
} else {
fprintf(stderr, "Note: Your bootloader does not understand the new START_FLASH command\n");
fprintf(stderr, " It is recommended that you update your bootloader\n\n");
}
return 0;
}
static int write_block(uint32_t address, uint8_t *data, uint32_t length) {
uint8_t block_buf[BLOCK_SIZE];
memset(block_buf, 0xFF, BLOCK_SIZE);
memcpy(block_buf, data, length);
for (int i = 0; i < 240; i += 48) {
SendCommandBL(CMD_SETUP_WRITE, i / 4, 0, 0, block_buf + i, 48);
if (wait_for_ack() < 0)
return -1;
}
SendCommandBL(CMD_FINISH_WRITE, address, 0, 0, block_buf + 240, 16);
return wait_for_ack();
}
// Write a file's segments to Flash
int flash_write(flash_file_t *ctx) {
fprintf(stdout, "Writing segments for file: %s\n", ctx->filename);
for (int i = 0; i < ctx->num_segs; i++) {
flash_seg_t *seg = &ctx->segments[i];
uint32_t length = seg->length;
uint32_t blocks = (length + BLOCK_SIZE - 1) / BLOCK_SIZE;
uint32_t end = seg->start + length;
fprintf(stdout, " 0x%08x..0x%08x [0x%x / %u blocks]", seg->start, end - 1, length, blocks);
fflush(stdout);
int block = 0;
uint8_t *data = seg->data;
uint32_t baddr = seg->start;
while (length) {
uint32_t block_size = length;
if (block_size > BLOCK_SIZE)
block_size = BLOCK_SIZE;
if (write_block(baddr, data, block_size) < 0) {
fprintf(stderr, " ERROR\n");
fprintf(stderr, "Error writing block %d of %u\n", block, blocks);
return -1;
}
data += block_size;
baddr += block_size;
length -= block_size;
block++;
fprintf(stdout, ".");
fflush(stdout);
}
fprintf(stderr, " OK\n");
fflush(stdout);
}
return 0;
}
// free a file context
void flash_free(flash_file_t *ctx) {
if (!ctx)
return;
if (ctx->segments) {
for (int i = 0; i < ctx->num_segs; i++)
free(ctx->segments[i].data);
free(ctx->segments);
ctx->segments = NULL;
ctx->num_segs = 0;
}
}
// just reset the unit
int flash_stop_flashing(void) {
SendCommandBL(CMD_HARDWARE_RESET, 0, 0, 0, NULL, 0);
msleep(100);
return 0;
}