u-boot/boot/bootmeth_pxe.c
Simon Glass dab2c2859b bootstd: Add an implementation of distro PXE boot
Add a bootmeth driver which handles distro boot from a network device, so
we can boot a bootflow using this commonly used mechanism.

In effect, this provides the same functionality as the 'pxe' command
and shares the same code. But the interface into it is via a bootmeth.

For now this requires the 'pxe' command be enabled. Future work may tidy
this up so that it can be used without CONFIG_CMDLINE being enabled.

Signed-off-by: Simon Glass <sjg@chromium.org>
2022-04-25 10:00:04 -04:00

187 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Bootmethod for distro boot using PXE (network boot)
*
* Copyright 2021 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#define LOG_CATEGORY UCLASS_BOOTSTD
#include <common.h>
#include <bootdev.h>
#include <bootflow.h>
#include <bootmeth.h>
#include <command.h>
#include <distro.h>
#include <dm.h>
#include <fs.h>
#include <log.h>
#include <malloc.h>
#include <mapmem.h>
#include <mmc.h>
#include <net.h>
#include <pxe_utils.h>
static int disto_pxe_getfile(struct pxe_context *ctx, const char *file_path,
char *file_addr, ulong *sizep)
{
struct distro_info *info = ctx->userdata;
ulong addr;
int ret;
addr = simple_strtoul(file_addr, NULL, 16);
ret = bootmeth_read_file(info->dev, info->bflow, file_path, addr,
sizep);
if (ret)
return log_msg_ret("read", ret);
return 0;
}
static int distro_pxe_check(struct udevice *dev, struct bootflow_iter *iter)
{
int ret;
/* This only works on network devices */
ret = bootflow_iter_uses_network(iter);
if (ret)
return log_msg_ret("net", ret);
return 0;
}
static int distro_pxe_read_bootflow(struct udevice *dev, struct bootflow *bflow)
{
const char *addr_str;
char fname[200];
char *bootdir;
ulong addr;
ulong size;
char *buf;
int ret;
addr_str = env_get("pxefile_addr_r");
if (!addr_str)
return log_msg_ret("pxeb", -EPERM);
addr = simple_strtoul(addr_str, NULL, 16);
log_debug("calling pxe_get()\n");
ret = pxe_get(addr, &bootdir, &size);
log_debug("pxe_get() returned %d\n", ret);
if (ret)
return log_msg_ret("pxeb", ret);
bflow->size = size;
/* Use the directory of the dhcp bootdir as our subdir, if provided */
if (bootdir) {
const char *last_slash;
int path_len;
last_slash = strrchr(bootdir, '/');
if (last_slash) {
path_len = (last_slash - bootdir) + 1;
bflow->subdir = malloc(path_len + 1);
memcpy(bflow->subdir, bootdir, path_len);
bflow->subdir[path_len] = '\0';
}
}
snprintf(fname, sizeof(fname), "%s%s",
bflow->subdir ? bflow->subdir : "", DISTRO_FNAME);
bflow->fname = strdup(fname);
if (!bflow->fname)
return log_msg_ret("name", -ENOMEM);
bflow->state = BOOTFLOWST_READY;
/* Allocate the buffer, including the \0 byte added by get_pxe_file() */
buf = malloc(size + 1);
if (!buf)
return log_msg_ret("buf", -ENOMEM);
memcpy(buf, map_sysmem(addr, 0), size + 1);
bflow->buf = buf;
return 0;
}
static int distro_pxe_read_file(struct udevice *dev, struct bootflow *bflow,
const char *file_path, ulong addr, ulong *sizep)
{
char *tftp_argv[] = {"tftp", NULL, NULL, NULL};
struct pxe_context *ctx = dev_get_priv(dev);
char file_addr[17];
ulong size;
int ret;
sprintf(file_addr, "%lx", addr);
tftp_argv[1] = file_addr;
tftp_argv[2] = (void *)file_path;
if (do_tftpb(ctx->cmdtp, 0, 3, tftp_argv))
return -ENOENT;
ret = pxe_get_file_size(&size);
if (ret)
return log_msg_ret("tftp", ret);
if (size > *sizep)
return log_msg_ret("spc", -ENOSPC);
*sizep = size;
return 0;
}
static int distro_pxe_boot(struct udevice *dev, struct bootflow *bflow)
{
struct pxe_context *ctx = dev_get_priv(dev);
struct cmd_tbl cmdtp = {}; /* dummy */
struct distro_info info;
ulong addr;
int ret;
addr = map_to_sysmem(bflow->buf);
info.dev = dev;
info.bflow = bflow;
info.cmdtp = &cmdtp;
ret = pxe_setup_ctx(ctx, &cmdtp, disto_pxe_getfile, &info, false,
bflow->subdir);
if (ret)
return log_msg_ret("ctx", -EINVAL);
ret = pxe_process(ctx, addr, false);
if (ret)
return log_msg_ret("bread", -EINVAL);
return 0;
}
static int distro_bootmeth_pxe_bind(struct udevice *dev)
{
struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
"PXE boot from a network device" : "PXE";
return 0;
}
static struct bootmeth_ops distro_bootmeth_pxe_ops = {
.check = distro_pxe_check,
.read_bootflow = distro_pxe_read_bootflow,
.read_file = distro_pxe_read_file,
.boot = distro_pxe_boot,
};
static const struct udevice_id distro_bootmeth_pxe_ids[] = {
{ .compatible = "u-boot,distro-pxe" },
{ }
};
U_BOOT_DRIVER(bootmeth_pxe) = {
.name = "bootmeth_pxe",
.id = UCLASS_BOOTMETH,
.of_match = distro_bootmeth_pxe_ids,
.ops = &distro_bootmeth_pxe_ops,
.bind = distro_bootmeth_pxe_bind,
.priv_auto = sizeof(struct pxe_context),
};