mirror of
https://github.com/FreeRTOS/FreeRTOS.git
synced 2025-06-18 22:33:36 +08:00
131 lines
3.2 KiB
C
131 lines
3.2 KiB
C
/*
|
|
* FreeRTOS V202012.00
|
|
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy of
|
|
* this software and associated documentation files (the "Software"), to deal in
|
|
* the Software without restriction, including without limitation the rights to
|
|
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
|
|
* the Software, and to permit persons to whom the Software is furnished to do so,
|
|
* subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in all
|
|
* copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
|
|
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
|
|
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
|
|
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
|
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*
|
|
* https://www.FreeRTOS.org
|
|
* https://github.com/FreeRTOS
|
|
*
|
|
*/
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#include <sys/types.h>
|
|
|
|
typedef struct UART_t {
|
|
volatile uint32_t DATA;
|
|
volatile uint32_t STATE;
|
|
volatile uint32_t CTRL;
|
|
volatile uint32_t INTSTATUS;
|
|
volatile uint32_t BAUDDIV;
|
|
} UART_t;
|
|
|
|
#define UART0_ADDR ((UART_t *)(0x40004000))
|
|
#define UART_DR(baseaddr) (*(unsigned int *)(baseaddr))
|
|
|
|
#define UART_STATE_TXFULL (1 << 0)
|
|
#define UART_CTRL_TX_EN (1 << 0)
|
|
#define UART_CTRL_RX_EN (1 << 1)
|
|
|
|
|
|
extern unsigned long _heap_bottom;
|
|
extern unsigned long _heap_top;
|
|
extern unsigned long g_ulBase;
|
|
|
|
static void *heap_end = 0;
|
|
|
|
/**
|
|
* @brief initializes the UART emulated hardware
|
|
*/
|
|
void uart_init()
|
|
{
|
|
UART0_ADDR->BAUDDIV = 16;
|
|
UART0_ADDR->CTRL = UART_CTRL_TX_EN;
|
|
}
|
|
|
|
/**
|
|
* @brief not used anywhere in the code
|
|
* @todo implement if necessary
|
|
*
|
|
*/
|
|
int _fstat(int file)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* @brief not used anywhere in the code
|
|
* @todo implement if necessary
|
|
*
|
|
*/
|
|
int _read(int file, char *buf, int len)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* @brief Write bytes to the UART channel to be displayed on the command line
|
|
* with qemu
|
|
* @param [in] file ignored
|
|
* @param [in] buf buffer to send
|
|
* @param [in] len length of the buffer
|
|
* @returns the number of bytes written
|
|
*/
|
|
int _write(int file, char *buf, int len)
|
|
{
|
|
int todo;
|
|
|
|
for (todo = 0; todo < len; todo++){
|
|
UART_DR(UART0_ADDR) = *buf++;
|
|
}
|
|
return len;
|
|
}
|
|
|
|
/**
|
|
* @brief function called by malloc and friends to reserve memory on the heap
|
|
* @param [in] incr the amount of bytes to increase or decrease
|
|
* @returns the previous top of the heap
|
|
* @note uses a global variable <b>heap_end</b> to keep track of the previous top
|
|
*/
|
|
void* _sbrk(int incr)
|
|
{
|
|
char *prev_heap_end;
|
|
|
|
if (heap_end == 0)
|
|
{
|
|
heap_end = (void*) &_heap_bottom;
|
|
}
|
|
|
|
prev_heap_end = heap_end;
|
|
|
|
if ((heap_end + incr) > (void*)&_heap_top)
|
|
{
|
|
return (void*)-1;
|
|
}
|
|
|
|
heap_end += incr;
|
|
|
|
return prev_heap_end;
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|