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[DRAFT] implement multiboot menu based on extlinux #596

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[DRAFT] implement multiboot menu based on extlinux #596

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43 changes: 31 additions & 12 deletions lk2nd/boot/boot.c
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
#include <list.h>
#include <stdlib.h>
#include <target.h>
#include <err.h>

#include <lk2nd/boot.h>
#include <lk2nd/hw/bdev.h>
Expand All @@ -20,7 +21,7 @@
/**
* lk2nd_scan_devices() - Scan filesystems and try to boot
*/
static void lk2nd_scan_devices(void)
int lk2nd_scan_devices(char **root_out, struct label **labels, int *default_label_idx, int* labels_count)
{
struct bdev_struct *bdevs = bio_get_bdevs();
char mountpoint[16];
Expand All @@ -34,7 +35,6 @@ static void lk2nd_scan_devices(void)
/* Skip top level block devices. */
if (!bdev->is_leaf)
continue;

/*
* Skip partitions that are too small to have a boot fs on.
*
Expand All @@ -48,7 +48,7 @@ static void lk2nd_scan_devices(void)

snprintf(mountpoint, sizeof(mountpoint), "/%s", bdev->name);
ret = fs_mount(mountpoint, "ext2", bdev->name);
if (ret < 0)
if (ret < 0 && ret != ERR_ALREADY_MOUNTED)
continue;

if (DEBUGLEVEL >= SPEW) {
Expand All @@ -57,10 +57,36 @@ static void lk2nd_scan_devices(void)
lk2nd_print_file_tree(mountpoint, " ");
}

lk2nd_try_extlinux(mountpoint);
ret = lk2nd_get_extlinux_labels(mountpoint, labels, default_label_idx, labels_count);
if (ret < 0)
continue;
*root_out = strdup(mountpoint);
break;
}
if (*root_out) {
return 0;
}

dprintf(INFO, "boot: Bootable file system not found. Reverting to android boot.\n");
return -1;
}

static void lk2nd_scan_and_boot(void) {
char *root;
struct label *labels;
int default_label_idx;
int labels_count;
int ret;

lk2nd_bdev_init();

ret = lk2nd_scan_devices(&root, &labels, &default_label_idx, &labels_count);
if (ret < 0) {
return;
}
ret = lk2nd_expand_conf_and_boot_label(
&labels[default_label_idx], root
);
}

/**
Expand All @@ -72,12 +98,5 @@ static void lk2nd_scan_devices(void)
*/
void lk2nd_boot(void)
{
static bool init_done = false;

if (!init_done) {
lk2nd_bdev_init();
init_done = true;
}

lk2nd_scan_devices();
lk2nd_scan_and_boot();
}
15 changes: 15 additions & 0 deletions lk2nd/boot/boot.h
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Original file line number Diff line number Diff line change
Expand Up @@ -7,10 +7,25 @@

#include <lk2nd/boot.h>

struct label {
const char *name;
const char *kernel;
const char *initramfs;
const char *dtb;
const char *dtbdir;
const char **dtboverlays;
const char *cmdline;
};

/* util.c */
void lk2nd_print_file_tree(char *root, char *prefix);

/* extlinux.c */
void lk2nd_try_extlinux(const char *mountpoint);
int lk2nd_get_extlinux_labels(const char *root, struct label **labels, int *default_label_idx, int* labels_count);
int lk2nd_expand_conf_and_boot_label(struct label *label, const char *root);

/* boot.c */
int lk2nd_scan_devices(char **root_out, struct label **labels, int *default_label_idx, int* labels_count);

#endif /* LK2ND_BOOT_BOOT_H */
119 changes: 83 additions & 36 deletions lk2nd/boot/extlinux.c
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -19,16 +19,6 @@

#include "boot.h"

struct label {
const char *name;
const char *kernel;
const char *initramfs;
const char *dtb;
const char *dtbdir;
const char **dtboverlays;
const char *cmdline;
};

enum token {
CMD_LABEL,
CMD_DEFAULT,
Expand Down Expand Up @@ -193,6 +183,21 @@ static int count_lines(char *data, size_t size)
return acc;
}

static void copy_label_data(struct label *label) {
if (label->name)
label->name = strdup(label->name);
if (label->kernel)
label->kernel = strdup(label->kernel);
if (label->initramfs)
label->initramfs = strdup(label->initramfs);
if (label->dtb)
label->dtb = strdup(label->dtb);
if (label->dtbdir)
label->dtbdir = strdup(label->dtbdir);
if (label->cmdline)
label->cmdline = strdup(label->cmdline);
}

/**
* parse_conf() - Extract default label from extlinux.conf
* @data: File contents
Expand All @@ -208,7 +213,7 @@ static int count_lines(char *data, size_t size)
*
* Returns: 0 on success or negative error on parse failure.
*/
static int parse_conf(char *data, size_t size, struct label *label)
static int parse_conf(char *data, size_t size, struct label **labels_out, int* default_label_idx, int* labels_count_out)
{
char *command = NULL, *value = NULL;
char *overlay, *saveptr;
Expand All @@ -219,7 +224,6 @@ static int parse_conf(char *data, size_t size, struct label *label)
} *commands;
int commands_count;
struct label *labels;
struct label *default_label = NULL;
const char *default_name = "";
int labels_count = 0;
int label_idx;
Expand Down Expand Up @@ -302,18 +306,22 @@ static int parse_conf(char *data, size_t size, struct label *label)
}
}

default_label = &labels[0];
*default_label_idx = 0;

for(i = 0; i < labels_count; i++) {
copy_label_data(&labels[i]);
}

for (i = 0; i < labels_count; ++i) {
if (!strcmp(default_name, labels[i].name)) {
default_label = &labels[i];
*default_label_idx = i;
break;
}
}

memcpy(label, default_label, sizeof(*label));
*labels_out = labels;
*labels_count_out = labels_count;

free(labels);
free(commands);

return 0;
Expand Down Expand Up @@ -635,17 +643,11 @@ static void lk2nd_boot_label(struct label *label)
0);
}

/**
* lk2nd_try_extlinux() - Try to boot with extlinux
*
* Check if /extlinux/extlinux.conf exists and try to
* boot it if so.
*/
void lk2nd_try_extlinux(const char *root)

int lk2nd_get_extlinux_labels(const char *root, struct label **labels, int *default_label_idx, int* labels_count)
{
struct filehandle *fileh;
struct file_stat stat;
struct label label = {0};
char path[64];
char *data;
int ret;
Expand All @@ -654,35 +656,80 @@ void lk2nd_try_extlinux(const char *root)
ret = fs_open_file(path, &fileh);
if (ret < 0) {
dprintf(SPEW, "No extlinux config in %s: %d\n", root, ret);
return;
return -1;
}

fs_stat_file(fileh, &stat);
data = malloc(stat.size + 1);
fs_read_file(fileh, data, 0, stat.size);
fs_close_file(fileh);

ret = parse_conf(data, stat.size, &label);
ret = parse_conf(data, stat.size, labels, default_label_idx, labels_count);
if (ret < 0)
goto error;

if (!expand_conf(&label, root))
goto error;
dprintf(INFO, "count: %d\n", *labels_count);

free(data);

dprintf(SPEW, "Parsed %s\n", path);
dprintf(SPEW, "kernel = %s\n", label.kernel);
dprintf(SPEW, "dtb = %s\n", label.dtb);
dprintf(SPEW, "dtbdir = %s\n", label.dtbdir);
dprintf(SPEW, "initramfs = %s\n", label.initramfs);
dprintf(SPEW, "cmdline = %s\n", label.cmdline);
return 0;

lk2nd_boot_label(&label);
error:
dprintf(INFO, "Failed to parse %s\n", path);
free(data);
return -1;
}

int lk2nd_expand_conf_and_boot_label(struct label *label, const char *root)
{
if (!expand_conf(label, root))
return -1;
dprintf(INFO, "kernel = %s\n", label->kernel);
dprintf(INFO, "dtb = %s\n", label->dtb);
dprintf(INFO, "dtbdir = %s\n", label->dtbdir);
dprintf(INFO, "initramfs = %s\n", label->initramfs);
dprintf(INFO, "cmdline = %s\n", label->cmdline);
lk2nd_boot_label(label);
return -1;
}

/**
* lk2nd_try_extlinux() - Try to boot with extlinux
*
* Check if /extlinux/extlinux.conf exists and try to
* boot it if so.
*/
void lk2nd_try_extlinux(const char *root)
{
struct label *labels;
struct label *label;
char path[64];
int ret;
int default_label_idx;
int labels_count;

ret = lk2nd_get_extlinux_labels(root, &labels, &default_label_idx, &labels_count);
if (ret < 0) {
return;
}

label = &labels[default_label_idx];

if (!expand_conf(label, root))
goto error;

dprintf(INFO, "Parsed %s\n", path);
dprintf(INFO, "kernel = %s\n", label->kernel);
dprintf(INFO, "dtb = %s\n", label->dtb);
dprintf(INFO, "dtbdir = %s\n", label->dtbdir);
dprintf(INFO, "initramfs = %s\n", label->initramfs);
dprintf(INFO, "cmdline = %s\n", label->cmdline);

lk2nd_boot_label(label);

free(labels);
return;

error:
dprintf(INFO, "Failed to parse extlinux.conf\n");
free(data);
}
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