Re: [coreboot] [patch 4/5] libpayload: Add an exec() and i386_do_exec() function

[Uwe Hermann]

On Tue, May 13, 2008 at 05:34:09PM -0600, [e-mail] wrote:
> Add functions for libpayload to execute other payloads in memory,
> and have those functions return cleanly.
>
> Signed-off-by: Jordan Crouse 
> Index: libpayload/i386/Makefile.inc
> ===================================================================
> --- libpayload.orig/i386/Makefile.inc	2008-05-13 13:40:07.000000000 -0600
> +++ libpayload/i386/Makefile.inc	2008-05-13 13:42:59.000000000 -0600
> @@ -29,3 +29,4 @@
>
> TARGETS-y += i386/head.o i386/main.o i386/sysinfo.o
>  TARGETS-y += i386/timer.o i386/coreboot.o i386/util.o
> +TARGETS-y += i386/exec.o
> Index: libpayload/i386/exec.S
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ libpayload/i386/exec.S	2008-05-13 13:42:59.000000000 -0600
> @@ -0,0 +1,64 @@

More reviews later, but NACK for this, missing license header.
> +/* calling syntax:  i386_do_exec(long addr, int argc, char **argv, int *ret) */
>
> +.align 4
> +.text
>
> +.global i386_do_exec
>    .type i386_do_exec,@function
>
> +i386_do_exec:
> pushl %ebp
>    movl %esp, %ebp
> pushl %eax
> # Put the run address in %eax
> movl 8(%ebp), %eax
> # Save off the rest of the registers
> pushl %esi
> pushl %ecx
> pushl %ebp
> # Push the argc and argv pointers on to the stack
> movl 12(%ebp), %esi
> movl 16(%ebp), %ecx
> pushl %esi
> pushl %ecx
> # Move a "magic" number on the stack - the other
> # payload will use this as a clue that the argc
> # and argv are sane
> movl  $12345678, %ecx
> pushl %ecx
> # Jump to the code
> call *%eax
> /* %eax has the return value */
> /* Skip over the argc/argv stuff still on the stack */
> addl $12, %esp
> # Get back %ebp
> popl %ebp
> # Get the pointer to the return value
> # and save the return value in it
> movl 20(%ebp), %ecx
> movl %eax, (%eax)
> # Get the rest of the saved registers
> popl %ecx
> popl %esi
> popl %eax
> # Restore the stack pointer
> movl %ebp,%esp
> popl %ebp
> ret
> Index: libpayload/i386/head.S
>
> --- libpayload.orig/i386/head.S	2008-05-13 13:40:07.000000000 -0600
> +++ libpayload/i386/head.S	2008-05-13 13:42:59.000000000 -0600
> @@ -63,13 +63,14 @@
>
> /* Let's rock. */
>    call start_main
> /* %eax has the return value - pass it on unmolested */
>
> _leave:
>    /* Get old stack pointer. */
>    popl %ebx
>
> /* Restore old stack. */
> movl %esp, %ebx
>
> movl %ebx, %esp
>
> /* Return to the original context. */
> lret
> ret
> Index: libpayload/libc/exec.c
>
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ libpayload/libc/exec.c	2008-05-13 13:42:59.000000000 -0600
> @@ -0,0 +1,52 @@
> +/*
> This file is part of the libpayload project.
> Copyright (C) 2008 Advanced Micro Devices, Inc.
> Redistribution and use in source and binary forms, with or without
> modification, are permitted provided that the following conditions
> are met:
> Redistributions of source code must retain the above copyright
> notice, this list of conditions and the following disclaimer.
> Redistributions in binary form must reproduce the above copyright
> notice, this list of conditions and the following disclaimer in the
> documentation and/or other materials provided with the distribution.
> The name of the author may not be used to endorse or promote products
> derived from this software without specific prior written permission.
> THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
> ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
> FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> SUCH DAMAGE.
> */
>
> +#include <libpayload.h>
>
> +#ifdef CONFIG_TARGET_I386
> +extern void i386_do_exec(long, int, char **, int *);
> +#endif
>
> +/**
> Execute code in memory
> @param ptr The entry point to jump to
> @return Return the return value from the entry point
> */
>
> +int exec(long addr, int argc, char **argv)
> +{
> int val = -1;
>
> +#ifdef CONFIG_TARGET_I386
> i386_do_exec(addr, argc, argv, &val);
>
> +#endif
> return val;
>
> +}
> Index: libpayload/include/libpayload.h
> ===================================================================
> --- libpayload.orig/include/libpayload.h	2008-05-13 13:42:59.000000000 -0600
> +++ libpayload/include/libpayload.h	2008-05-13 13:42:59.000000000 -0600
> @@ -145,6 +145,9 @@
>  void *calloc(size_t nmemb, size_t size);
>  void *realloc(void *ptr, size_t size);
>
> +/* libc/exec.c */
> +int exec(long addr, int argc, char **argv);
>
> /* libc/lib.c */
>  int bcd2dec(int b);
>  int dec2bcd(int d);
> Index: libpayload/libc/Makefile.inc
> ===================================================================
> --- libpayload.orig/libc/Makefile.inc	2008-05-13 13:40:07.000000000 -0600
> +++ libpayload/libc/Makefile.inc	2008-05-13 13:42:59.000000000 -0600
> @@ -29,4 +29,4 @@
>
> TARGETS-y += libc/malloc.o libc/printf.o libc/console.o libc/string.o
>  TARGETS-y += libc/memory.o libc/ctype.o libc/ipchecksum.o libc/lib.o
> -TARGETS-y += libc/rand.o libc/time.o libc/lar.o
> +TARGETS-y += libc/rand.o libc/time.o libc/lar.o libc/exec.o