esp-idf/components/esp_tee/subproject/main/common/syscall_stubs.c

/*
 * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <pthread.h>
#include <unistd.h>

#include "soc/soc_caps.h"
#include "rom/libc_stubs.h"

#include "esp_attr.h"
#include "esp_cpu.h"
#include "esp_random.h"

#include "sdkconfig.h"

#if CONFIG_LIBC_NEWLIB
// NOTE: Remove compile-time warnings for the below newlib-provided functions
struct _reent *__getreent(void)
{
    return _GLOBAL_REENT;
}

int _fstat_r(struct _reent *r, int fd, struct stat *st)
{
    errno = ENOSYS;
    return -1;
}

int _close_r(struct _reent *r, int fd)
{
    errno = ENOSYS;
    return -1;
}

off_t _lseek_r(struct _reent *r, int fd, off_t offset, int whence)
{
    errno = ENOSYS;
    return -1;
}

ssize_t _read_r(struct _reent *r, int fd, void *ptr, size_t len)
{
    errno = ENOSYS;
    return -1;
}

ssize_t _write_r(struct _reent *r, int fd, const void *ptr, size_t len)
{
    errno = ENOSYS;
    return -1;
}

ssize_t _open_r(struct _reent *r, const char *path, int flags, int mode)
{
    errno = ENOSYS;
    return -1;
}

int _getpid_r(struct _reent *r)
{
    return 1;
}

int _kill_r(struct _reent *r, int pid, int sig)
{
    errno = ENOSYS;
    return -1;
}

int _getentropy_r(struct _reent *r, void *buffer, size_t length)
{
    esp_fill_random(buffer, length);
    return 0;
}

struct syscall_stub_table *syscall_table_ptr;
static struct syscall_stub_table *syscall_table_ptr_ree;

static struct syscall_stub_table s_stub_table_tee = {
    .__getreent = &__getreent,
};

void IRAM_ATTR syscall_enter_tee(void)
{
    if (syscall_table_ptr) {
        syscall_table_ptr_ree = syscall_table_ptr;
        syscall_table_ptr = &s_stub_table_tee;
    }
}

void IRAM_ATTR syscall_exit_tee(void)
{
    if (syscall_table_ptr_ree) {
        syscall_table_ptr = syscall_table_ptr_ree;
        syscall_table_ptr_ree = NULL;
    }
}
#else
/*
 * Picolibc does not initialize 'errno' and places it in the TBSS section.
 *
 * To allow convenient initialization and support interoperability with Newlib,
 * 'errno' is defined in the TDATA section. The linker script ensures that
 * it is positioned at the beginning of the TDATA segment.
 */
__thread int errno __attribute__((section(".tdata.errno"))) = 0;

int *__errno(void)
{
    return &errno;
}

int fstat(int fd, struct stat *st)
{
    errno = ENOSYS;
    return -1;
}

int close(int fd)
{
    errno = ENOSYS;
    return -1;
}

off_t lseek(int fd, off_t offset, int whence)
{
    errno = ENOSYS;
    return -1;
}

ssize_t read(int fd, void *ptr, size_t len)
{
    errno = ENOSYS;
    return -1;
}

ssize_t write(int fd, const void *ptr, size_t len)
{
    errno = ENOSYS;
    return -1;
}

int getpid(void)
{
    return 1;
}

int kill(int pid, int sig)
{
    errno = ENOSYS;
    return -1;
}

int getentropy(void *buffer, size_t length)
{
    esp_fill_random(buffer, length);
    return 0;
}

int open(const char *path, int flags, ...)
{
    errno = ENOSYS;
    return -1;
}

int rename(const char *src, const char *dst)
{
    errno = ENOSYS;
    return -1;
}

int unlink(const char *path)
{
    errno = ENOSYS;
    return -1;
}

extern uint32_t _tee_tdata_start;
static void *s_tp_ree[SOC_CPU_CORES_NUM];

void IRAM_ATTR syscall_enter_tee(void)
{
    int core_id = esp_cpu_get_core_id();
    s_tp_ree[core_id] = esp_cpu_get_threadptr();
    esp_cpu_set_threadptr(&_tee_tdata_start);
}

void IRAM_ATTR syscall_exit_tee(void)
{
    int core_id = esp_cpu_get_core_id();
    esp_cpu_set_threadptr(s_tp_ree[core_id]);
}
#endif // CONFIG_LIBC_NEWLIB

void *pthread_getspecific(pthread_key_t key)
{
    return NULL;
}

int pthread_setspecific(pthread_key_t key, const void *value)
{
    return 0;
}

int pthread_key_create(pthread_key_t *key, void (*destructor)(void*))
{
    errno = ENOSYS;
    return -1;
}

int pthread_key_delete(pthread_key_t key)
{
    errno = ENOSYS;
    return -1;
}

int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
{
    errno = ENOSYS;
    return -1;
}

int pthread_mutex_destroy(pthread_mutex_t *mutex)
{
    errno = ENOSYS;
    return -1;
}

int pthread_mutex_lock(pthread_mutex_t *mutex)
{
    errno = ENOSYS;
    return -1;
}

int pthread_mutex_unlock(pthread_mutex_t *mutex)
{
    errno = ENOSYS;
    return -1;
}

void *__cxa_get_globals(void)
{
    return NULL;
}

void *__cxa_get_globals_fast(void)
{
    return NULL;
}

int __cxa_thread_atexit(void (*func)(void *), void *arg, void *dso)
{
    return 0;
}

void *_sbrk(ptrdiff_t incr)
{
    return (void *) -1;
}

void esp_tee_include_syscalls_impl(void)
{

}

int _unlink_r(struct _reent *r, const char *path)
{
    errno = ENOSYS;
    return -1;
}

int _rename_r(struct _reent *r, const char *src, const char *dst)
{
    errno = ENOSYS;
    return -1;
}