Commit 500856eb authored by Rafal Jaworowski's avatar Rafal Jaworowski

API for external applications.

This is an API for external (standalone) applications running on top of
U-Boot, and is meant to be more extensible and robust than the existing
jumptable mechanism. It is similar to UNIX syscall approach. See api/README
for more details.

Included is the demo application using this new framework (api_examples).

Please note this is still an experimental feature, and is turned off by
default.
Signed-off-by: 's avatarRafal Jaworowski <raj@semihalf.com>
parent 26a41790
......@@ -243,6 +243,9 @@ LIBS += $(shell if [ -d post/board/$(BOARDDIR) ]; then echo \
"post/board/$(BOARDDIR)/libpost$(BOARD).a"; fi)
LIBS += common/libcommon.a
LIBS += libfdt/libfdt.a
ifeq ($(CONFIG_API),y)
LIBS += api/libapi.a
endif
LIBS := $(addprefix $(obj),$(LIBS))
.PHONY : $(LIBS)
......@@ -255,6 +258,10 @@ PLATFORM_LIBS += -L $(shell dirname `$(CC) $(CFLAGS) -print-libgcc-file-name`) -
SUBDIRS = tools \
examples
ifeq ($(CONFIG_API),y)
SUBDIRS += api_examples
endif
.PHONY : $(SUBDIRS)
ifeq ($(CONFIG_NAND_U_BOOT),y)
......@@ -2749,6 +2756,7 @@ clean:
rm -f $(obj)board/bf537-stamp/u-boot.lds $(obj)board/bf561-ezkit/u-boot.lds
rm -f $(obj)include/bmp_logo.h
rm -f $(obj)nand_spl/u-boot-spl $(obj)nand_spl/u-boot-spl.map
rm -f $(obj)api_examples/demo
clobber: clean
find $(OBJTREE) -type f \( -name .depend \
......@@ -2762,6 +2770,8 @@ clobber: clean
rm -f $(obj)tools/inca-swap-bytes $(obj)cpu/mpc824x/bedbug_603e.c
rm -f $(obj)include/asm/proc $(obj)include/asm/arch $(obj)include/asm
[ ! -d $(OBJTREE)/nand_spl ] || find $(obj)nand_spl -lname "*" -print | xargs rm -f
find $(obj)api_examples -lname "*" -print | xargs rm -f
rm -f $(obj)api_examples/demo
ifeq ($(OBJTREE),$(SRCTREE))
mrproper \
......
#
# (C) Copyright 2007 Semihalf
#
# See file CREDITS for list of people who contributed to this
# project.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundatio; either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#
include $(TOPDIR)/config.mk
LIB = $(obj)libapi.a
COBJS = api.o api_net.o api_storage.o api_platform-$(ARCH).o
SRCS := $(COBJS:.o=.c)
OBJS := $(addprefix $(obj),$(COBJS))
all: $(LIB)
$(LIB): $(obj).depend $(OBJS)
$(AR) $(ARFLAGS) $@ $(OBJS)
# defines $(obj).depend target
include $(SRCTREE)/rules.mk
sinclude $(obj).depend
U-Boot machine/arch independent API for external apps
=====================================================
1. Main assumptions
- there is a single entry point (syscall) to the API
- per current design the syscall is a C-callable function in the U-Boot
text, which might evolve into a real syscall using machine exception trap
once this initial version proves functional
- the consumer app is responsible for producing appropriate context (call
number and arguments)
- upon entry, the syscall dispatches the call to other (existing) U-Boot
functional areas like networking or storage operations
- consumer application will recognize the API is available by searching
a specified (assumed by convention) range of address space for the
signature
- the U-Boot integral part of the API is meant to be thin and non-intrusive,
leaving as much processing as possible on the consumer application side,
for example it doesn't keep states, but relies on hints from the app and
so on
- optional (CONFIG_API)
2. Calls
- console related (getc, putc, tstc etc.)
- system (reset, platform info)
- time (delay, current)
- env vars (enumerate all, get, set)
- devices (enumerate all, open, close, read, write); currently two classes
of devices are recognized and supported: network and storage (ide, scsi,
usb etc.)
3. Structure overview
- core API, integral part of U-Boot, mandatory
- implements the single entry point (mimics UNIX syscall)
- glue
- entry point at the consumer side, allows to make syscall, mandatory
part
- helper conveniency wrappers so that consumer app does not have to use
the syscall directly, but in a more friendly manner (a la libc calls),
optional part
- consumer application
- calls directly, or leverages the provided glue mid-layer
/*
* (C) Copyright 2007 Semihalf
*
* Written by: Rafal Jaworowski <raj@semihalf.com>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*/
#include <config.h>
#if defined(CONFIG_API)
#include <command.h>
#include <common.h>
#include <malloc.h>
#include <linux/types.h>
#include <api_public.h>
#include "api_private.h"
#define DEBUG
#undef DEBUG
/* U-Boot routines needed */
extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
extern uchar (*env_get_char)(int);
extern uchar *env_get_addr(int);
/*****************************************************************************
*
* This is the API core.
*
* API_ functions are part of U-Boot code and constitute the lowest level
* calls:
*
* - they know what values they need as arguments
* - their direct return value pertains to the API_ "shell" itself (0 on
* success, some error code otherwise)
* - if the call returns a value it is buried within arguments
*
****************************************************************************/
#ifdef DEBUG
#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt, ##args); } while (0)
#else
#define debugf(fmt, args...)
#endif
typedef int (*cfp_t)(va_list argp);
static int calls_no;
/*
* pseudo signature:
*
* int API_getc(int *c)
*/
static int API_getc(va_list ap)
{
int *c;
if ((c = (int *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
*c = getc();
return 0;
}
/*
* pseudo signature:
*
* int API_tstc(int *c)
*/
static int API_tstc(va_list ap)
{
int *t;
if ((t = (int *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
*t = tstc();
return 0;
}
/*
* pseudo signature:
*
* int API_putc(char *ch)
*/
static int API_putc(va_list ap)
{
char *c;
if ((c = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
putc(*c);
return 0;
}
/*
* pseudo signature:
*
* int API_puts(char **s)
*/
static int API_puts(va_list ap)
{
char *s;
if ((s = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
puts(s);
return 0;
}
/*
* pseudo signature:
*
* int API_reset(void)
*/
static int API_reset(va_list ap)
{
do_reset(NULL, 0, 0, NULL);
/* NOT REACHED */
return 0;
}
/*
* pseudo signature:
*
* int API_get_sys_info(struct sys_info *si)
*
* fill out the sys_info struct containing selected parameters about the
* machine
*/
static int API_get_sys_info(va_list ap)
{
struct sys_info *si;
si = (struct sys_info *)va_arg(ap, u_int32_t);
if (si == NULL)
return API_ENOMEM;
return (platform_sys_info(si)) ? 0 : API_ENODEV;
}
/*
* pseudo signature:
*
* int API_udelay(unsigned long *udelay)
*/
static int API_udelay(va_list ap)
{
unsigned long *d;
if ((d = (unsigned long *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
udelay(*d);
return 0;
}
/*
* pseudo signature:
*
* int API_get_timer(unsigned long *current, unsigned long *base)
*/
static int API_get_timer(va_list ap)
{
unsigned long *base, *cur;
cur = (unsigned long *)va_arg(ap, u_int32_t);
if (cur == NULL)
return API_EINVAL;
base = (unsigned long *)va_arg(ap, u_int32_t);
if (base == NULL)
return API_EINVAL;
*cur = get_timer(*base);
return 0;
}
/*****************************************************************************
*
* pseudo signature:
*
* int API_dev_enum(struct device_info *)
*
*
* cookies uniqely identify the previously enumerated device instance and
* provide a hint for what to inspect in current enum iteration:
*
* - net: &eth_device struct address from list pointed to by eth_devices
*
* - storage: block_dev_desc_t struct address from &ide_dev_desc[n],
* &scsi_dev_desc[n] and similar tables
*
****************************************************************************/
static int API_dev_enum(va_list ap)
{
struct device_info *di;
/* arg is ptr to the device_info struct we are going to fill out */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
if (di->cookie == NULL) {
/* start over - clean up enumeration */
dev_enum_reset(); /* XXX shouldn't the name contain 'stor'? */
debugf("RESTART ENUM\n");
/* net device enumeration first */
if (dev_enum_net(di))
return 0;
}
/*
* The hidden assumption is there can only be one active network
* device and it is identified upon enumeration (re)start, so there's
* no point in trying to find network devices in other cases than the
* (re)start and hence the 'next' device can only be storage
*/
if (!dev_enum_storage(di))
/* make sure we mark there are no more devices */
di->cookie = NULL;
return 0;
}
static int API_dev_open(va_list ap)
{
struct device_info *di;
int err = 0;
/* arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
/* Allow only one consumer of the device at a time */
if (di->state == DEV_STA_OPEN)
return API_EBUSY;
if (di->cookie == NULL)
return API_ENODEV;
if (di->type & DEV_TYP_STOR)
err = dev_open_stor(di->cookie);
else if (di->type & DEV_TYP_NET)
err = dev_open_net(di->cookie);
else
err = API_ENODEV;
if (!err)
di->state = DEV_STA_OPEN;
return err;
}
static int API_dev_close(va_list ap)
{
struct device_info *di;
int err = 0;
/* arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
if (di->state == DEV_STA_CLOSED)
return 0;
if (di->cookie == NULL)
return API_ENODEV;
if (di->type & DEV_TYP_STOR)
err = dev_close_stor(di->cookie);
else if (di->type & DEV_TYP_NET)
err = dev_close_net(di->cookie);
else
/*
* In case of unknown device we cannot change its state, so
* only return error code
*/
err = API_ENODEV;
if (!err)
di->state = DEV_STA_CLOSED;
return err;
}
/*
* Notice: this is for sending network packets only, as U-Boot does not
* support writing to storage at the moment (12.2007)
*
* pseudo signature:
*
* int API_dev_write(
* struct device_info *di,
* void *buf,
* int *len
* )
*
* buf: ptr to buffer from where to get the data to send
*
* len: length of packet to be sent (in bytes)
*
*/
static int API_dev_write(va_list ap)
{
struct device_info *di;
void *buf;
int *len;
int err = 0;
/* 1. arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
/* XXX should we check if device is open? i.e. the ->state ? */
if (di->cookie == NULL)
return API_ENODEV;
/* 2. arg is ptr to buffer from where to get data to write */
buf = (void *)va_arg(ap, u_int32_t);
if (buf == NULL)
return API_EINVAL;
/* 3. arg is length of buffer */
len = (int *)va_arg(ap, u_int32_t);
if (len == NULL)
return API_EINVAL;
if (*len <= 0)
return API_EINVAL;
if (di->type & DEV_TYP_STOR)
/*
* write to storage is currently not supported by U-Boot:
* no storage device implements block_write() method
*/
return API_ENODEV;
else if (di->type & DEV_TYP_NET)
err = dev_write_net(di->cookie, buf, *len);
else
err = API_ENODEV;
return err;
}
/*
* pseudo signature:
*
* int API_dev_read(
* struct device_info *di,
* void *buf,
* size_t *len,
* unsigned long *start
* size_t *act_len
* )
*
* buf: ptr to buffer where to put the read data
*
* len: ptr to length to be read
* - network: len of packet to read (in bytes)
* - storage: # of blocks to read (can vary in size depending on define)
*
* start: ptr to start block (only used for storage devices, ignored for
* network)
*
* act_len: ptr to where to put the len actually read
*/
static int API_dev_read(va_list ap)
{
struct device_info *di;
void *buf;
lbasize_t *len_stor, *act_len_stor;
lbastart_t *start;
int *len_net, *act_len_net;
/* 1. arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
/* XXX should we check if device is open? i.e. the ->state ? */
if (di->cookie == NULL)
return API_ENODEV;
/* 2. arg is ptr to buffer from where to put the read data */
buf = (void *)va_arg(ap, u_int32_t);
if (buf == NULL)
return API_EINVAL;
if (di->type & DEV_TYP_STOR) {
/* 3. arg - ptr to var with # of blocks to read */
len_stor = (lbasize_t *)va_arg(ap, u_int32_t);
if (!len_stor)
return API_EINVAL;
if (*len_stor <= 0)
return API_EINVAL;
/* 4. arg - ptr to var with start block */
start = (lbastart_t *)va_arg(ap, u_int32_t);
/* 5. arg - ptr to var where to put the len actually read */
act_len_stor = (lbasize_t *)va_arg(ap, u_int32_t);
if (!act_len_stor)
return API_EINVAL;
*act_len_stor = dev_read_stor(di->cookie, buf, *len_stor, *start);
} else if (di->type & DEV_TYP_NET) {
/* 3. arg points to the var with length of packet to read */
len_net = (int *)va_arg(ap, u_int32_t);
if (!len_net)
return API_EINVAL;
if (*len_net <= 0)
return API_EINVAL;
/* 4. - ptr to var where to put the len actually read */
act_len_net = (int *)va_arg(ap, u_int32_t);
if (!act_len_net)
return API_EINVAL;
*act_len_net = dev_read_net(di->cookie, buf, *len_net);
} else
return API_ENODEV;
return 0;
}
/*
* pseudo signature:
*
* int API_env_get(const char *name, char **value)
*
* name: ptr to name of env var
*/
static int API_env_get(va_list ap)
{
char *name, **value;
if ((name = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
if ((value = (char **)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
*value = getenv(name);
return 0;
}
/*
* pseudo signature:
*
* int API_env_set(const char *name, const char *value)
*
* name: ptr to name of env var
*
* value: ptr to value to be set
*/
static int API_env_set(va_list ap)
{
char *name, *value;
if ((name = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
if ((value = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
setenv(name, value);
return 0;
}
/*
* pseudo signature:
*
* int API_env_enum(const char *last, char **next)
*
* last: ptr to name of env var found in last iteration
*/
static int API_env_enum(va_list ap)
{
int i, n;
char *last, **next;
last = (char *)va_arg(ap, u_int32_t);
if ((next = (char **)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
if (last == NULL)
/* start over */
*next = ((char *)env_get_addr(0));
else {
*next = last;
for (i = 0; env_get_char(i) != '\0'; i = n + 1) {
for (n = i; env_get_char(n) != '\0'; ++n) {
if (n >= CFG_ENV_SIZE) {
/* XXX shouldn't we set *next = NULL?? */
return 0;
}
}
if (envmatch((uchar *)last, i) < 0)
continue;
/* try to get next name */
i = n + 1;
if (env_get_char(i) == '\0') {
/* no more left */
*next = NULL;
return 0;
}
*next = ((char *)env_get_addr(i));
return 0;
}
}
return 0;
}
static cfp_t calls_table[API_MAXCALL] = { NULL, };
/*
* The main syscall entry point - this is not reentrant, only one call is
* serviced until finished.
*
* e.g. syscall(1, int *, u_int32_t, u_int32_t, u_int32_t, u_int32_t);
*
* call: syscall number
*
* retval: points to the return value placeholder, this is the place the
* syscall puts its return value, if NULL the caller does not
* expect a return value
*
* ... syscall arguments (variable number)
*
* returns: 0 if the call not found, 1 if serviced
*/
int syscall(int call, int *retval, ...)
{
va_list ap;
int rv;
if (call < 0 || call >= calls_no || calls_table[call] == NULL) {
debugf("invalid call #%d\n", call);
return 0;
}
if (calls_table[call] == NULL) {
debugf("syscall #%d does not have a handler\n", call);
return 0;
}
va_start(ap, retval);
rv = calls_table[call](ap);
if (retval != NULL)
*retval = rv;
return 1;
}
void api_init(void)
{
struct api_signature *sig = NULL;
/* TODO put this into linker set one day... */
calls_table[API_RSVD] = NULL;
calls_table[API_GETC] = &API_getc;
calls_table[API_PUTC] = &API_putc;
calls_table[API_TSTC] = &API_tstc;
calls_table[API_PUTS] = &API_puts;
calls_table[API_RESET] = &API_reset;
calls_table[API_GET_SYS_INFO] = &API_get_sys_info;
calls_table[API_UDELAY] = &API_udelay;
calls_table[API_GET_TIMER] = &API_get_timer;
calls_table[API_DEV_ENUM] = &API_dev_enum;
calls_table[API_DEV_OPEN] = &API_dev_open;
calls_table[API_DEV_CLOSE] = &API_dev_close;
calls_table[API_DEV_READ] = &API_dev_read;
calls_table[API_DEV_WRITE] = &API_dev_write;
calls_table[API_ENV_GET] = &API_env_get;
calls_table[API_ENV_SET] = &API_env_set;
calls_table[API_ENV_ENUM] = &API_env_enum;
calls_no = API_MAXCALL;
debugf("API initialized with %d calls\n", calls_no);
dev_stor_init();
/*
* Produce the signature so the API consumers can find it
*/
sig = malloc(sizeof(struct api_signature));
if (sig == NULL) {
printf("API: could not allocate memory for the signature!\n");