user_stack.h File Reference

#include <stdint.h>

Include dependency graph for user_stack.h:

Macros
#define	MAX_STACK_ARGS   64
	Maximum number of arguments/env vars copied to the user stack.
#define	STACK_ALIGNMENT   16
	Alignment (in bytes) of the returned user stack pointer.
#define	AT_NULL   0
	End of the auxiliary vector.
#define	AT_PAGESZ   6
	Page size.
#define	AT_ENTRY   9
	Entry point of the program.

Functions
uintptr_t	create_user_stack (uintptr_t stack_top, int argc, char *const argv[], char *const envp[], uintptr_t entry)

Function Documentation

create_user_stack()

uintptr_t create_user_stack	(	uintptr_t	stack_top,
		int	argc,
		char *const	argv[],
		char *const	envp[],
		uintptr_t	entry )

Builds the initial user stack for a program about to be executed.

The stack is written downward from stack_top.

+-----------------------—+ <- stack_top | strings | +-----------------------—+ <- returned stack pointer | argc | | argv[0..argc-1] | | NULL | | envp[0..] | | NULL | | AT_PAGESZ, page_size | | AT_ENTRY, entry | | AT_NULL, 0 | +-----------------------—+

The returned pointer is 16-byte aligned.

Parameters

stack_top	the top (high address) of the user stack
argc	the number of arguments
argv	the argument list
envp	the environment list
entry	the program entry point

Returns

the initial stack pointer, or 0 on error