main.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <malloc.h>

#include "loader.h"
#include "app/sysent.h"

#define APP_PATH
#define APP_NAME "app-striped.elf"
#define APP_STACK_SIZE 2048

extern int open(const char *path, int mode, ...);

static const sysent_t sysentries = { /* */
	open, /* */
	close, /* */
	write, /* */
	read, /* */
	printf, /* */
	scanf /* */
};

static const ELFSymbol_t exports[] = { { "syscalls", (void*) &sysentries } };
static const ELFEnv_t env = { exports, sizeof(exports) / sizeof(*exports) };

int main(void)
{
	exec_elf(APP_PATH APP_NAME, &env);
	puts("Done");
	return 0;
}

void *do_alloc(size_t size, size_t align, ELFSecPerm_t perm)
{
	(void) perm;
	/* TODO Change perms with MPU */
	return memalign(align, size);
}

void arch_jumpTo(entry_t entry)
{
	void *stack = do_alloc(APP_STACK_SIZE, 8, ELF_SEC_READ | ELF_SEC_WRITE);
	if (stack) {
		register uint32_t saved = 0;
		void *tos = stack + APP_STACK_SIZE;

		/* s->saved */
		__asm__ volatile("MOV %0, sp\n\t" : : "r"(saved));
		/* tos->MSP */
		__asm__ volatile("MOV sp, %0\n\t" : : "r"(tos));
		/* push saved */
		__asm__ volatile("PUSH {%0}\n\t" : : "r"(saved));

		entry();

		/* pop saved */
		__asm__ volatile("POP {%0}\n\t" : : "r"(saved));
		/* saved->sp */
		__asm__ volatile("MOV sp, %0\n\t" : : "r"(saved));

		free(stack);
	} else
		perror("Stack alloc");
}