mirror of
https://github.com/google/pebble.git
synced 2025-06-04 17:23:12 +00:00
Import of the watch repository from Pebble
This commit is contained in:
commit
3b92768480
10334 changed files with 2564465 additions and 0 deletions
52
src/fw/util/ihex.c
Normal file
52
src/fw/util/ihex.c
Normal file
|
@ -0,0 +1,52 @@
|
|||
/*
|
||||
* Copyright 2024 Google LLC
|
||||
*
|
||||
* 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 "util/ihex.h"
|
||||
|
||||
typedef struct IHEXRecord {
|
||||
char start;
|
||||
char data_count[2];
|
||||
char address[4];
|
||||
char type[2];
|
||||
char data[]; // Variable data and checksum
|
||||
} IHEXRecord;
|
||||
|
||||
static void prv_hexlify(char *str, uint32_t value, uint8_t num_bytes) {
|
||||
for (int i = num_bytes * 2 - 1; i >= 0; --i) {
|
||||
uint8_t nibble = (value >> (4 * i)) & 0xF;
|
||||
if (nibble >= 0xA) {
|
||||
*str++ = 'A' + (nibble - 0xA);
|
||||
} else {
|
||||
*str++ = '0' + nibble;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void ihex_encode(uint8_t *out, uint8_t type, uint16_t address,
|
||||
const void *data, uint8_t data_len) {
|
||||
IHEXRecord *record = (IHEXRecord *)out;
|
||||
uint8_t checksum = data_len + (address >> 8) + (address & 0xff) + type;
|
||||
record->start = ':';
|
||||
prv_hexlify(record->data_count, data_len, sizeof(data_len));
|
||||
prv_hexlify(record->address, address, sizeof(address));
|
||||
prv_hexlify(record->type, type, sizeof(type));
|
||||
for (uint16_t i = 0; i < data_len; ++i) {
|
||||
uint8_t data_byte = ((uint8_t *)data)[i];
|
||||
checksum += data_byte;
|
||||
prv_hexlify(&record->data[i*2], data_byte, sizeof(data_byte));
|
||||
}
|
||||
prv_hexlify(&record->data[data_len*2], ~checksum + 1, sizeof(checksum));
|
||||
}
|
Loading…
Add table
Add a link
Reference in a new issue