9ffcc985c8
All non-ASCII characters replaced with ASCII equivalents: - Greek letters: mu->u, phi->phi, lambda->lambda, etc. - Box drawing: single/double -> +, -, |, = - Math symbols: x (multiply), != (not equal), -> (arrow), etc. - Superscripts/subscripts: ^2, ^3, _1, _2, etc. - Emoji/bullets: [OK], [FAIL], [!], *, etc. - parse_benchmark.py: simplified regex (only ASCII 'us' needed now) 190 files changed. Zero non-ASCII bytes remain in source. Build verified: library, benchmarks, selftests all pass.
129 lines
3.8 KiB
C++
129 lines
3.8 KiB
C++
/**
|
|
* STM32F103ZET6 Syscalls
|
|
* Redirects printf() -> USART1 (PA9=TX, 115200 baud)
|
|
* Provides _sbrk for malloc/new
|
|
*
|
|
* Bare-metal, no HAL dependency
|
|
*/
|
|
|
|
#include <cstdint>
|
|
#include <cerrno>
|
|
#include <sys/stat.h>
|
|
|
|
// ============================================================================
|
|
// USART1 Register Definitions
|
|
// ============================================================================
|
|
#define GPIOA_BASE 0x40010800UL
|
|
#define GPIOA_CRH (*(volatile uint32_t*)(GPIOA_BASE + 0x04))
|
|
|
|
#define USART1_BASE 0x40013800UL
|
|
#define USART1_SR (*(volatile uint32_t*)(USART1_BASE + 0x00))
|
|
#define USART1_DR (*(volatile uint32_t*)(USART1_BASE + 0x04))
|
|
#define USART1_BRR (*(volatile uint32_t*)(USART1_BASE + 0x08))
|
|
#define USART1_CR1 (*(volatile uint32_t*)(USART1_BASE + 0x0C))
|
|
|
|
// RCC
|
|
#define RCC_BASE 0x40021000UL
|
|
#define RCC_APB2ENR (*(volatile uint32_t*)(RCC_BASE + 0x18))
|
|
#define RCC_APB2ENR_IOPAEN (1U << 2)
|
|
#define RCC_APB2ENR_USART1EN (1U << 14)
|
|
|
|
// USART_SR bits
|
|
#define USART_SR_TXE (1U << 7)
|
|
|
|
// USART_CR1 bits
|
|
#define USART_CR1_UE (1U << 13) // USART enable
|
|
#define USART_CR1_TE (1U << 3) // Transmitter enable
|
|
#define USART_CR1_RE (1U << 2) // Receiver enable
|
|
|
|
static bool uart_initialized = false;
|
|
|
|
/**
|
|
* Initialize USART1 on PA9 (TX) at 115200 baud
|
|
* Call this AFTER SystemInit (72MHz clock configured)
|
|
*/
|
|
void uart_init() {
|
|
if (uart_initialized) return;
|
|
|
|
// Enable GPIOA + USART1 clocks
|
|
RCC_APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_USART1EN;
|
|
|
|
// PA9 = USART1_TX: Alternate function push-pull, 50MHz
|
|
// CRH controls pins 8-15, PA9 is bits [7:4]
|
|
uint32_t crh = GPIOA_CRH;
|
|
crh &= ~(0xFU << 4); // Clear PA9 config
|
|
crh |= (0xBU << 4); // AF push-pull, 50MHz (MODE=11, CNF=10)
|
|
GPIOA_CRH = crh;
|
|
|
|
// PA10 = USART1_RX: Input floating (default) -- no change needed
|
|
|
|
// Baud rate: 72MHz / 115200 = 625 = 0x271
|
|
USART1_BRR = 625; // 72000000 / 115200 = 625.0
|
|
|
|
// Enable USART: TX + RX + UE
|
|
USART1_CR1 = USART_CR1_UE | USART_CR1_TE | USART_CR1_RE;
|
|
|
|
uart_initialized = true;
|
|
}
|
|
|
|
/**
|
|
* Send one byte over USART1 (blocking)
|
|
*/
|
|
static inline void uart_putc(char c) {
|
|
while (!(USART1_SR & USART_SR_TXE)) {} // Wait for TXE
|
|
USART1_DR = static_cast<uint32_t>(c);
|
|
}
|
|
|
|
// ============================================================================
|
|
// Newlib syscall stubs (redirect stdio to USART1)
|
|
// ============================================================================
|
|
|
|
extern "C" {
|
|
|
|
// Redirect _write to USART1
|
|
int _write(int fd, const char* buf, int len) {
|
|
(void)fd;
|
|
if (!uart_initialized) uart_init();
|
|
for (int i = 0; i < len; i++) {
|
|
if (buf[i] == '\n') uart_putc('\r'); // CR+LF
|
|
uart_putc(buf[i]);
|
|
}
|
|
return len;
|
|
}
|
|
|
|
// Heap management
|
|
extern uint32_t end; // Defined by linker (_end)
|
|
extern uint32_t _estack;
|
|
|
|
static uint8_t* heap_ptr = nullptr;
|
|
|
|
void* _sbrk(ptrdiff_t incr) {
|
|
if (heap_ptr == nullptr) {
|
|
heap_ptr = reinterpret_cast<uint8_t*>(&end);
|
|
}
|
|
|
|
uint8_t* prev = heap_ptr;
|
|
uint8_t* new_ptr = heap_ptr + incr;
|
|
|
|
// Check against stack (leave 1KB margin)
|
|
if (new_ptr >= reinterpret_cast<uint8_t*>(&_estack) - 1024) {
|
|
errno = ENOMEM;
|
|
return reinterpret_cast<void*>(-1);
|
|
}
|
|
|
|
heap_ptr = new_ptr;
|
|
return prev;
|
|
}
|
|
|
|
// No-op stubs
|
|
int _close(int fd) { (void)fd; return -1; }
|
|
int _fstat(int fd, struct stat* st) { (void)fd; st->st_mode = S_IFCHR; return 0; }
|
|
int _isatty(int fd) { (void)fd; return 1; }
|
|
int _lseek(int fd, int ptr, int dir) { (void)fd; (void)ptr; (void)dir; return 0; }
|
|
int _read(int fd, char* buf, int len) { (void)fd; (void)buf; (void)len; return 0; }
|
|
void _exit(int status) { (void)status; while (1) {} }
|
|
int _kill(int pid, int sig) { (void)pid; (void)sig; return -1; }
|
|
int _getpid() { return 1; }
|
|
|
|
} // extern "C"
|