// SPDX-License-Identifier: GPL-2.0
#include <linux/libfdt_env.h>
#include <asm/setup.h>
#include <libfdt.h>
#include "misc.h"
#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND)
#define do_extend_cmdline 1
#else
#define do_extend_cmdline 0
#endif
#define NR_BANKS 16
static int node_offset(void *fdt, const char *node_path)
{
int offset = fdt_path_offset(fdt, node_path);
if (offset == -FDT_ERR_NOTFOUND)
/* Add the node to root if not found, dropping the leading '/' */
offset = fdt_add_subnode(fdt, 0, node_path + 1);
return offset;
}
static int setprop(void *fdt, const char *node_path, const char *property,
void *val_array, int size)
{
int offset = node_offset(fdt, node_path);
if (offset < 0)
return offset;
return fdt_setprop(fdt, offset, property, val_array, size);
}
static int setprop_string(void *fdt, const char *node_path,
const char *property, const char *string)
{
int offset = node_offset(fdt, node_path);
if (offset < 0)
return offset;
return fdt_setprop_string(fdt, offset, property, string);
}
static int setprop_cell(void *fdt, const char *node_path,
const char *property, uint32_t val)
{
int offset = node_offset(fdt, node_path);
if (offset < 0)
return offset;
return fdt_setprop_cell(fdt, offset, property, val);
}
static const void *getprop(const void *fdt, const char *node_path,
const char *property, int *len)
{
int offset = fdt_path_offset(fdt, node_path);
if (offset == -FDT_ERR_NOTFOUND)
return NULL;
return fdt_getprop(fdt, offset, property, len);
}
static uint32_t get_cell_size(const void *fdt)
{
int len;
uint32_t cell_size = 1;
const __be32 *size_len = getprop(fdt, "/", "#size-cells", &len);
if (size_len)
cell_size = fdt32_to_cpu(*size_len);
return cell_size;
}
static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline)
{
char cmdline[COMMAND_LINE_SIZE];
const char *fdt_bootargs;
char *ptr = cmdline;
int len = 0;
/* copy the fdt command line into the buffer */
fdt_bootargs = getprop(fdt, "/chosen", "bootargs", &len);
if (fdt_bootargs)
if (len < COMMAND_LINE_SIZE) {
memcpy(ptr, fdt_bootargs, len);
/* len is the length of the string
* including the NULL terminator */
ptr += len - 1;
}
/* and append the ATAG_CMDLINE */
if (fdt_cmdline) {
len = strlen(fdt_cmdline);
if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) {
*ptr++ = ' ';
memcpy(ptr, fdt_cmdline, len);
ptr += len;
}
}
*ptr = '\0';
setprop_string(fdt, "/chosen", "bootargs", cmdline);
}
static void hex_str(char *out, uint32_t value)
{
uint32_t digit;
int idx;
for (idx = 7; idx >= 0; idx--) {
digit = value >> 28;
value <<= 4;
digit &= 0xf;
if (digit < 10)
digit += '0';
else
digit += 'A'-10;
*out++ = digit;
}
*out = '\0';
}
/*
* Convert and fold provided ATAGs into the provided FDT.
*
* Return values:
* = 0 -> pretend success
* = 1 -> bad ATAG (may retry with another possible ATAG pointer)
* < 0 -> error from libfdt
*/
int atags_to_fdt(void *atag_list, void *fdt, int total_space)
{
struct tag *atag = atag_list;
/* In the case of 64 bits memory size, need to reserve 2 cells for
* address and size for each bank */
__be32 mem_reg_property[2 * 2 * NR_BANKS];
int memcount = 0;
int ret, memsize;
/* make sure we've got an aligned pointer */
if ((u32)atag_list & 0x3)
return 1;
/* if we get a DTB here we're done already */
if (*(__be32 *)atag_list == cpu_to_fdt32(FDT_MAGIC))
return 0;
/* validate the ATAG */
if (atag->hdr.tag != ATAG_CORE ||
(atag->hdr.size != tag_size(tag_core) &&
atag->hdr.size != 2))
return 1;
/* let's give it all the room it could need */
ret = fdt_open_into(fdt, fdt, total_space);
if (ret < 0)
return ret;
for_each_tag(atag, atag_list) {
if (atag->hdr.tag == ATAG_CMDLINE) {
/* Append the ATAGS command line to the device tree
* command line.
* NB: This means that if the same parameter is set in
* the device tree and in the tags, the one from the
* tags will be chosen.
*/
if (do_extend_cmdline)
merge_fdt_bootargs(fdt,
atag->u.cmdline.cmdline);
else
setprop_string(fdt, "/chosen", "bootargs",
atag->u.cmdline.cmdline);
} else if (atag->hdr.tag == ATAG_MEM) {
if (memcount >= sizeof(mem_reg_property)/4)
continue;
if (!atag->u.mem.size)
continue;
memsize = get_cell_size(fdt);
if (memsize == 2) {
/* if memsize is 2, that means that
* each data needs 2 cells of 32 bits,
* so the data are 64 bits */
__be64 *mem_reg_prop64 =
(__be64 *)mem_reg_property;
mem_reg_prop64[memcount++] =
cpu_to_fdt64(atag->u.mem.start);
mem_reg_prop64[memcount++] =
cpu_to_fdt64(atag->u.mem.size);
} else {
mem_reg_property[memcount++] =
cpu_to_fdt32(atag->u.mem.start);
mem_reg_property[memcount++] =
cpu_to_fdt32(atag->u.mem.size);
}
} else if (atag->hdr.tag == ATAG_INITRD2) {
uint32_t initrd_start, initrd_size;
initrd_start = atag->u.initrd.start;
initrd_size = atag->u.initrd.size;
setprop_cell(fdt, "/chosen", "linux,initrd-start",
initrd_start);
setprop_cell(fdt, "/chosen", "linux,initrd-end",
initrd_start + initrd_size);
} else if (atag->hdr.tag == ATAG_SERIAL) {
char serno[16+2];
hex_str(serno, atag->u.serialnr.high);
hex_str(serno+8, atag->u.serialnr.low);
setprop_string(fdt, "/", "serial-number", serno);
}
}
if (memcount) {
setprop(fdt, "/memory", "reg", mem_reg_property,
4 * memcount * memsize);
}
return fdt_pack(fdt);
}
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