mirror of
https://github.com/Rockbox/rockbox.git
synced 2025-10-14 02:27:39 -04:00
Untested (i.e. will almost certainly brick your device if you attempt to use it) first attempt at making mkamsboot store the original firmware as a UCL compressed image. If it works, then this means we have about 40KB (depending on target and OF version) for our bootloader code. I repeat: This is UNTESTED and needs reviewing fully before attempting to install on a device.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@18675 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Dave Chapman
parent
fe72d57996
commit
757f5112e2
5 changed files with 305 additions and 96 deletions
|
|
@ -1,4 +1,3 @@
|
|||
|
||||
# Change INFILE to point to your original firmware file
|
||||
INFILE=$(HOME)/FW/AMS/CLIP/m300a-1.1.17A.bin
|
||||
|
||||
|
|
@ -6,6 +5,8 @@ INFILE=$(HOME)/FW/AMS/CLIP/m300a-1.1.17A.bin
|
|||
# (e.g.) m300a.bin
|
||||
OUTFILE=patched.bin
|
||||
|
||||
# The uclpack command
|
||||
UCLPACK=../../../tools/uclpack
|
||||
|
||||
all: amsinfo $(OUTFILE)
|
||||
|
||||
|
|
@ -15,6 +16,9 @@ amsinfo: amsinfo.c
|
|||
mkamsboot: mkamsboot.c
|
||||
gcc -o mkamsboot -W -Wall mkamsboot.c
|
||||
|
||||
extract_fw: extract_fw.c
|
||||
gcc -o extract_fw -W -Wall extract_fw.c
|
||||
|
||||
# Rules for our test ARM application - assemble, link, then extract
|
||||
# the binary code
|
||||
|
||||
|
|
@ -22,13 +26,34 @@ test.o: test.S
|
|||
arm-elf-as -o test.o test.S
|
||||
|
||||
test.elf: test.o
|
||||
arm-elf-ld -e 0 -o test.elf test.o
|
||||
arm-elf-ld -e 0 -Ttext=0 -o test.elf test.o
|
||||
|
||||
test.bin: test.elf
|
||||
arm-elf-objcopy -O binary test.elf test.bin
|
||||
|
||||
$(OUTFILE): mkamsboot test.bin $(INFILE)
|
||||
./mkamsboot $(INFILE) test.bin $(OUTFILE)
|
||||
# Rules for the ucl unpack function - this is inserted in the padding at
|
||||
# the end of the original firmware block
|
||||
nrv2e_d8.o: nrv2e_d8.S
|
||||
arm-elf-gcc -DPURE_THUMB -c -o nrv2e_d8.o nrv2e_d8.S
|
||||
|
||||
# NOTE: this function has no absolute references, so the link address (-e)
|
||||
# is irrelevant. We just link at address 0.
|
||||
nrv2e_d8.elf: nrv2e_d8.o
|
||||
arm-elf-ld -e 0 -Ttext=0 -o nrv2e_d8.elf nrv2e_d8.o
|
||||
|
||||
nrv2e_d8.bin: nrv2e_d8.elf
|
||||
arm-elf-objcopy -O binary nrv2e_d8.elf nrv2e_d8.bin
|
||||
|
||||
firmware_block.ucl: firmware_block.bin
|
||||
$(UCLPACK) --best --2e firmware_block.bin firmware_block.ucl
|
||||
|
||||
firmware_block.bin: $(INFILE) extract_fw
|
||||
./extract_fw $(INFILE) firmware_block.bin
|
||||
|
||||
$(OUTFILE): mkamsboot firmware_block.ucl test.bin nrv2e_d8.bin $(INFILE)
|
||||
./mkamsboot $(INFILE) firmware_block.ucl test.bin nrv2e_d8.bin $(OUTFILE)
|
||||
|
||||
clean:
|
||||
rm -fr amsinfo mkamsboot test.bin test.o test.elf $(OUTFILE) *~
|
||||
rm -fr amsinfo mkamsboot test.o test.elf test.bin extract_fw \
|
||||
nrv2e_d8.o nrv2e_d8.elf nrv2e_d8.bin firmware_block.bin \
|
||||
firmware_block.ucl $(OUTFILE) *~
|
||||
|
|
|
|||
129
utils/AMS/hacking/extract_fw.c
Normal file
129
utils/AMS/hacking/extract_fw.c
Normal file
|
|
@ -0,0 +1,129 @@
|
|||
/*
|
||||
|
||||
extract_fw.c - extract the main firmware image from a Sansa V2 (AMS) firmware
|
||||
file
|
||||
|
||||
Copyright (C) Dave Chapman 2008
|
||||
|
||||
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 2 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, write to the Free Software
|
||||
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
|
||||
|
||||
*/
|
||||
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdint.h>
|
||||
#include <sys/types.h>
|
||||
#include <sys/stat.h>
|
||||
#include <fcntl.h>
|
||||
#include <unistd.h>
|
||||
#include <string.h>
|
||||
|
||||
|
||||
/* Win32 compatibility */
|
||||
#ifndef O_BINARY
|
||||
#define O_BINARY 0
|
||||
#endif
|
||||
|
||||
|
||||
static off_t filesize(int fd) {
|
||||
struct stat buf;
|
||||
|
||||
if (fstat(fd,&buf) < 0) {
|
||||
perror("[ERR] Checking filesize of input file");
|
||||
return -1;
|
||||
} else {
|
||||
return(buf.st_size);
|
||||
}
|
||||
}
|
||||
|
||||
static uint32_t get_uint32le(unsigned char* p)
|
||||
{
|
||||
return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
|
||||
}
|
||||
|
||||
void usage(void)
|
||||
{
|
||||
printf("Usage: extract_fw <firmware file> <output file>\n");
|
||||
|
||||
exit(1);
|
||||
}
|
||||
|
||||
int main(int argc, char* argv[])
|
||||
{
|
||||
char *infile, *outfile;
|
||||
int fdin, fdout;
|
||||
off_t len;
|
||||
uint32_t n;
|
||||
unsigned char* buf;
|
||||
uint32_t firmware_size;
|
||||
|
||||
if(argc != 3) {
|
||||
usage();
|
||||
}
|
||||
|
||||
infile = argv[1];
|
||||
outfile = argv[2];
|
||||
|
||||
/* Open the firmware file */
|
||||
fdin = open(infile,O_RDONLY|O_BINARY);
|
||||
|
||||
if (fdin < 0) {
|
||||
fprintf(stderr,"[ERR] Could not open %s for reading\n",infile);
|
||||
return 1;
|
||||
}
|
||||
|
||||
if ((len = filesize(fdin)) < 0)
|
||||
return 1;
|
||||
|
||||
/* We will need no more memory than the total size plus the bootloader size
|
||||
padded to a boundary */
|
||||
if ((buf = malloc(len)) == NULL) {
|
||||
fprintf(stderr,"[ERR] Could not allocate buffer for input file (%d bytes)\n",(int)len);
|
||||
return 1;
|
||||
}
|
||||
|
||||
n = read(fdin, buf, len);
|
||||
|
||||
if (n != (uint32_t)len) {
|
||||
fprintf(stderr,"[ERR] Could not read firmware file\n");
|
||||
return 1;
|
||||
}
|
||||
|
||||
close(fdin);
|
||||
|
||||
/* Get the firmware size */
|
||||
firmware_size = get_uint32le(&buf[0x0c]);
|
||||
|
||||
fdout = open(outfile, O_CREAT|O_TRUNC|O_WRONLY|O_BINARY,0666);
|
||||
|
||||
if (fdout < 0) {
|
||||
fprintf(stderr,"[ERR] Could not open %s for writing\n",outfile);
|
||||
return 1;
|
||||
}
|
||||
|
||||
n = write(fdout, buf + 0x400, firmware_size);
|
||||
|
||||
if (n != (uint32_t)firmware_size) {
|
||||
fprintf(stderr,"[ERR] Could not write firmware block\n");
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Clean up */
|
||||
close(fdout);
|
||||
free(buf);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -26,26 +26,33 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
|
|||
|
||||
Insert a Rockbox bootloader into an AMS original firmware file.
|
||||
|
||||
The first instruction in an AMS firmware file is always of the form:
|
||||
We replace the main firmware block (bytes 0x400..padded_firmware_size+0x400)
|
||||
with the following:
|
||||
|
||||
ldr pc, [pc, #xxx]
|
||||
Bytes 0..(firmware_size-ucl_size) - Our bootloader code
|
||||
Bytes (firmware_size-ucl_size)..firmware_size - UCL compressed OF image
|
||||
Bytes firmware_size..padded_firmware_size - UCL decompress function
|
||||
|
||||
where [pc, #xxx] contains the entry point of the firmware - e.g. 0x00000138
|
||||
mkamsboot writes the following values at offsets into our bootloader code:
|
||||
|
||||
mkamsboot appends the Rockbox bootloader to the end of the original
|
||||
firmware block in the firmware file and shifts the remaining contents of the firmware file to make space for it.
|
||||
0x20 - Entry point (plus 1 - for thumb mode) of the ucl_unpack function
|
||||
0x24 - Location of the UCL compressed version of the original firmware block
|
||||
|
||||
It also replaces the contents of [pc, #xxx] with the entry point of
|
||||
our bootloader - i.e. the length of the original firmware block plus 4
|
||||
bytes.
|
||||
mkamsboot then corrects the length (to include the UCL decompress
|
||||
function) and checksum in the main firmware headers (both copies),
|
||||
creating a new legal firmware file which can be installed on the
|
||||
device.
|
||||
|
||||
It then stores the original entry point from [pc, #xxx] in the first
|
||||
four bytes of the Rockbox bootloader image, which is used by the
|
||||
bootloader to dual-boot.
|
||||
Our bootloader first checks for the "dual-boot" keypress, and then either:
|
||||
|
||||
Finally, mkamsboot corrects the length and checksum in the main
|
||||
firmware headers (both copies), creating a new legal firmware file
|
||||
which can be installed on the device.
|
||||
a) Branches to the ucl_unpack function, which will then branch to 0x0 after
|
||||
decompressing the OF.
|
||||
|
||||
b) Continues running with our test code
|
||||
|
||||
This method uses no RAM outside the padded area of the original
|
||||
firmware block - the UCL compression can happen in-place when the
|
||||
compressed image is stored at the end of the destination buffer.
|
||||
|
||||
*/
|
||||
|
||||
|
|
@ -106,35 +113,35 @@ static int calc_checksum(unsigned char* buf, uint32_t n)
|
|||
|
||||
void usage(void)
|
||||
{
|
||||
printf("Usage: mkamsboot <firmware file> <boot file> <output file>\n");
|
||||
printf("Usage: mkamsboot <firmware file> <ucl image> <boot file> <ucl unpack file> <output file>\n");
|
||||
|
||||
exit(1);
|
||||
}
|
||||
|
||||
int main(int argc, char* argv[])
|
||||
{
|
||||
char *infile, *bootfile, *outfile;
|
||||
int fdin, fdboot,fdout;
|
||||
char *infile, *uclfile, *bootfile, *uclunpackfile, *outfile;
|
||||
int fdin, fducl, fdboot, fduclunpack, fdout;
|
||||
off_t len;
|
||||
uint32_t n;
|
||||
unsigned char* buf;
|
||||
uint32_t ldr;
|
||||
uint32_t origoffset;
|
||||
uint32_t firmware_size;
|
||||
uint32_t firmware_paddedsize;
|
||||
uint32_t bootloader_size;
|
||||
uint32_t new_paddedsize;
|
||||
uint32_t ucl_size;
|
||||
uint32_t uclunpack_size;
|
||||
uint32_t sum,filesum;
|
||||
uint32_t new_length;
|
||||
uint32_t i;
|
||||
|
||||
if(argc != 4) {
|
||||
if(argc != 6) {
|
||||
usage();
|
||||
}
|
||||
|
||||
infile = argv[1];
|
||||
bootfile = argv[2];
|
||||
outfile = argv[3];
|
||||
uclfile = argv[2];
|
||||
bootfile = argv[3];
|
||||
uclunpackfile = argv[4];
|
||||
outfile = argv[5];
|
||||
|
||||
/* Open the bootloader file */
|
||||
fdboot = open(bootfile, O_RDONLY|O_BINARY);
|
||||
|
|
@ -147,6 +154,28 @@ int main(int argc, char* argv[])
|
|||
bootloader_size = filesize(fdboot);
|
||||
|
||||
|
||||
/* Open the UCL-compressed image of the firmware block */
|
||||
fduclunpack = open(uclunpackfile, O_RDONLY|O_BINARY);
|
||||
if (fduclunpack < 0)
|
||||
{
|
||||
fprintf(stderr,"[ERR] Could not open %s for reading\n",uclunpackfile);
|
||||
return 1;
|
||||
}
|
||||
|
||||
uclunpack_size = filesize(fduclunpack);
|
||||
|
||||
|
||||
/* Open the UCL-compressed image of the firmware block */
|
||||
fducl = open(uclfile, O_RDONLY|O_BINARY);
|
||||
if (fducl < 0)
|
||||
{
|
||||
fprintf(stderr,"[ERR] Could not open %s for reading\n",uclfile);
|
||||
return 1;
|
||||
}
|
||||
|
||||
ucl_size = filesize(fducl);
|
||||
|
||||
|
||||
/* Open the firmware file */
|
||||
fdin = open(infile,O_RDONLY|O_BINARY);
|
||||
|
||||
|
|
@ -158,9 +187,8 @@ int main(int argc, char* argv[])
|
|||
if ((len = filesize(fdin)) < 0)
|
||||
return 1;
|
||||
|
||||
/* We will need no more memory than the total size plus the bootloader size
|
||||
padded to a boundary */
|
||||
if ((buf = malloc(len + PAD_TO_BOUNDARY(bootloader_size))) == NULL) {
|
||||
/* Allocate memory for the OF image - we don't change the size */
|
||||
if ((buf = malloc(len)) == NULL) {
|
||||
fprintf(stderr,"[ERR] Could not allocate buffer for input file (%d bytes)\n",(int)len);
|
||||
return 1;
|
||||
}
|
||||
|
|
@ -181,91 +209,83 @@ int main(int argc, char* argv[])
|
|||
|
||||
firmware_paddedsize = PAD_TO_BOUNDARY(firmware_size);
|
||||
|
||||
/* Total new size */
|
||||
new_paddedsize = PAD_TO_BOUNDARY(firmware_size + bootloader_size);
|
||||
|
||||
/* Total new size of firmware file */
|
||||
new_length = len + (new_paddedsize - firmware_paddedsize);
|
||||
|
||||
fprintf(stderr,"Original firmware size - 0x%08x\n",firmware_size);
|
||||
fprintf(stderr,"Padded firmware size - 0x%08x\n",firmware_paddedsize);
|
||||
fprintf(stderr,"Bootloader size - 0x%08x\n",bootloader_size);
|
||||
fprintf(stderr,"New padded size - 0x%08x\n",new_paddedsize);
|
||||
fprintf(stderr,"Original total size of firmware - 0x%08x\n",(int)len);
|
||||
fprintf(stderr,"New total size of firmware - 0x%08x\n",new_length);
|
||||
|
||||
if (firmware_paddedsize != new_paddedsize) {
|
||||
/* We don't know how to safely increase the firmware size, so abort */
|
||||
|
||||
fprintf(stderr,
|
||||
"[ERR] Bootloader too large (%d bytes - %d bytes available), aborting.\n",
|
||||
bootloader_size, firmware_paddedsize - firmware_size);
|
||||
fprintf(stderr,"Original firmware size - %d bytes\n",firmware_size);
|
||||
fprintf(stderr,"Padded firmware size - %d bytes\n",firmware_paddedsize);
|
||||
fprintf(stderr,"Bootloader size - %d bytes\n",bootloader_size);
|
||||
fprintf(stderr,"UCL image size - %d bytes\n",ucl_size);
|
||||
fprintf(stderr,"UCL unpack function size - %d bytes\n",uclunpack_size);
|
||||
fprintf(stderr,"Original total size of firmware - %d bytes\n",(int)len);
|
||||
|
||||
/* Check we have room for our bootloader - in the future, we could UCL
|
||||
pack this image as well if we need to. */
|
||||
if (bootloader_size > (firmware_size - ucl_size)) {
|
||||
fprintf(stderr,"[ERR] Bootloader too large (%d bytes, %d available)\n",
|
||||
bootloader_size, firmware_size - ucl_size);
|
||||
return 1;
|
||||
}
|
||||
|
||||
ldr = get_uint32le(&buf[0x400]);
|
||||
|
||||
if ((ldr & 0xfffff000) != 0xe59ff000) {
|
||||
fprintf(stderr,"[ERR] Firmware file doesn't start with an \"ldr pc, [pc, #xx]\" instruction.\n");
|
||||
/* Check we have enough room for the UCL unpack function. This
|
||||
needs to be outside the firmware block, so if we wanted to
|
||||
support every firmware version, we could store this function in
|
||||
the main firmware block, and then copy it to an unused part of
|
||||
RAM. */
|
||||
if (uclunpack_size > (firmware_paddedsize - firmware_size)) {
|
||||
fprintf(stderr,"[ERR] UCL unpack function too large (%d bytes, %d available)\n",
|
||||
uclunpack_size, firmware_paddedsize - firmware_size);
|
||||
return 1;
|
||||
}
|
||||
origoffset = (ldr&0xfff) + 8;
|
||||
|
||||
printf("original firmware entry point: 0x%08x\n",get_uint32le(buf + 0x400 + origoffset));
|
||||
printf("New entry point: 0x%08x\n", firmware_size + 4);
|
||||
/* Zero the original firmware area - not needed, but helps debugging */
|
||||
memset(buf + 0x400, 0, firmware_size);
|
||||
|
||||
#if 0
|
||||
/* Replace the "Product: Express" string with "Rockbox" */
|
||||
i = 0x400 + firmware_size - 7;
|
||||
while ((i > 0x400) && (memcmp(&buf[i],"Express",7)!=0))
|
||||
i--;
|
||||
|
||||
i = (i + 3) & ~0x3;
|
||||
|
||||
if (i >= 0x400) {
|
||||
printf("Replacing \"Express\" string at offset 0x%08x\n",i);
|
||||
memcpy(&buf[i],"Rockbox",7);
|
||||
} else {
|
||||
printf("Could not find \"Express\" string to replace\n");
|
||||
}
|
||||
#endif
|
||||
|
||||
n = read(fdboot, buf + 0x400 + firmware_size, bootloader_size);
|
||||
/* Locate our bootloader code at the start of the firmware block */
|
||||
n = read(fdboot, buf + 0x400, bootloader_size);
|
||||
|
||||
if (n != bootloader_size) {
|
||||
fprintf(stderr,"[ERR] Could not bootloader file\n");
|
||||
fprintf(stderr,"[ERR] Could not load bootloader file\n");
|
||||
return 1;
|
||||
}
|
||||
close(fdboot);
|
||||
|
||||
/* Replace first word of the bootloader with the original entry point */
|
||||
put_uint32le(buf + 0x400 + firmware_size, get_uint32le(buf + 0x400 + origoffset));
|
||||
/* Locate the compressed image of the original firmware block at the end
|
||||
of the firmware block */
|
||||
n = read(fducl, buf + 0x400 + firmware_size - ucl_size, ucl_size);
|
||||
|
||||
#if 1
|
||||
put_uint32le(buf + 0x400 + origoffset, firmware_size + 4);
|
||||
#endif
|
||||
if (n != ucl_size) {
|
||||
fprintf(stderr,"[ERR] Could not load ucl file\n");
|
||||
return 1;
|
||||
}
|
||||
close(fducl);
|
||||
|
||||
|
||||
/* Locate our UCL unpack function in the padding after the firmware block */
|
||||
n = read(fduclunpack, buf + 0x400 + firmware_size, uclunpack_size);
|
||||
|
||||
if (n != uclunpack_size) {
|
||||
fprintf(stderr,"[ERR] Could not load uclunpack file\n");
|
||||
return 1;
|
||||
}
|
||||
close(fduclunpack);
|
||||
|
||||
put_uint32le(&buf[0x420], firmware_size + 1); /* UCL unpack entry point */
|
||||
put_uint32le(&buf[0x424], firmware_size - ucl_size); /* Location of OF */
|
||||
|
||||
/* Update checksum */
|
||||
sum = calc_checksum(buf + 0x400,firmware_size + bootloader_size);
|
||||
sum = calc_checksum(buf + 0x400,firmware_size + uclunpack_size);
|
||||
|
||||
put_uint32le(&buf[0x04], sum);
|
||||
put_uint32le(&buf[0x204], sum);
|
||||
|
||||
/* Update firmware block count */
|
||||
put_uint32le(&buf[0x08], new_paddedsize / 0x200);
|
||||
put_uint32le(&buf[0x208], new_paddedsize / 0x200);
|
||||
|
||||
/* Update firmware size */
|
||||
put_uint32le(&buf[0x0c], firmware_size + bootloader_size);
|
||||
put_uint32le(&buf[0x20c], firmware_size + bootloader_size);
|
||||
put_uint32le(&buf[0x0c], firmware_size + uclunpack_size);
|
||||
put_uint32le(&buf[0x20c], firmware_size + uclunpack_size);
|
||||
|
||||
/* Update the whole-file checksum */
|
||||
filesum = 0;
|
||||
for (i=0;i < new_length - 4; i+=4)
|
||||
for (i=0;i < (unsigned)len - 4; i+=4)
|
||||
filesum += get_uint32le(&buf[i]);
|
||||
|
||||
put_uint32le(buf + new_length - 4, filesum);
|
||||
put_uint32le(buf + len - 4, filesum);
|
||||
|
||||
|
||||
/* Write the new firmware */
|
||||
|
|
@ -276,7 +296,12 @@ int main(int argc, char* argv[])
|
|||
return 1;
|
||||
}
|
||||
|
||||
write(fdout, buf, new_length);
|
||||
n = write(fdout, buf, len);
|
||||
|
||||
if (n != (unsigned)len) {
|
||||
fprintf(stderr,"[ERR] Could not write firmware file\n");
|
||||
return 1;
|
||||
}
|
||||
|
||||
close(fdout);
|
||||
|
||||
|
|
|
|||
|
|
@ -77,13 +77,15 @@ ucl_nrv2e_decompress_8: .globl ucl_nrv2e_decompress_8 @ ARM mode
|
|||
For SAFE mode: at call, *plen_dst must be allowed length of output buffer.
|
||||
*/
|
||||
adr r12,1+.thumb_nrv2e_d8; bx r12 @ enter THUMB mode
|
||||
#endif
|
||||
.code 16 @ THUMB mode
|
||||
.thumb_func
|
||||
#endif
|
||||
|
||||
.thumb_nrv2e_d8:
|
||||
#if 0
|
||||
push {r2,r3, r4,r5,r6,r7, lr}
|
||||
#define sp_DST0 0 /* stack offset of original dst */
|
||||
#endif
|
||||
add srclim,len,src @ srclim= eof_src;
|
||||
#if 1==SAFE /*{*/
|
||||
ldr tmp,[r3] @ len_dst
|
||||
|
|
@ -103,12 +105,17 @@ bad_src_n2e: # return value will be 1
|
|||
add src,#1
|
||||
#endif /*}*/
|
||||
eof_n2e:
|
||||
#if 0
|
||||
pop {r3,r4} @ r3= orig_dst; r4= plen_dst
|
||||
sub src,srclim @ 0 if actual src length equals expected length
|
||||
sub dst,r3 @ actual dst length
|
||||
str dst,[r4]
|
||||
pop {r4,r5,r6,r7 /*,pc*/}
|
||||
pop {r1}; bx r1 @ "pop {,pc}" fails return to ARM mode on ARMv4T
|
||||
#else
|
||||
mov r0, #0
|
||||
bx r0 /* Branch to 0x0, switch to ARM mode */
|
||||
#endif
|
||||
|
||||
get1_n2e: @ In: Carry set [from adding 0x80000000 (1<<31) to itself]
|
||||
ldrb bits,[src] @ zero-extend next byte
|
||||
|
|
|
|||
|
|
@ -1,11 +1,34 @@
|
|||
/* int ucl_nrv2e_decompress_8(const unsigned char *src, unsigned char *dst,
|
||||
unsigned long *dst_len) */
|
||||
|
||||
/* This value is filled in by mkamsboot */
|
||||
originalentry: .word 0
|
||||
.text
|
||||
.global ucl_nrv2e_decompress_8
|
||||
|
||||
|
||||
/* Vectors */
|
||||
ldr pc, =start
|
||||
.word 0
|
||||
.word 0
|
||||
.word 0
|
||||
.word 0
|
||||
.word 0
|
||||
.word 0
|
||||
.word 0
|
||||
|
||||
/* These values are filled in by mkamsboot - don't move them from offset 0x20 */
|
||||
ucl_unpack: .word 0 /* Entry point (plus 1 - for thumb) of ucl_unpack */
|
||||
ucl_start: .word 0 /* Start of the ucl-compressed OF image */
|
||||
|
||||
|
||||
start:
|
||||
/* A delay loop - just to prove we're running */
|
||||
mov r1, #0x500000 /* Approximately 5 seconds */
|
||||
loop: subs r1, r1, #1
|
||||
bne loop
|
||||
|
||||
/* Now branch back to the original firmware's entry point */
|
||||
ldr pc, originalentry
|
||||
/* Call the ucl decompress function, which will branch to 0x0
|
||||
on completion */
|
||||
ldr r0, ucl_start /* Source */
|
||||
mov r1, #0 /* Destination */
|
||||
ldr r2, ucl_unpack
|
||||
bx r2
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue