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semi_loader.c
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semi_loader.c
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/*
* Copyright (c) 2012 Linaro Limited
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of Linaro Limited nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*/
#include <string.h>
#include "libfdt.h"
#include "semihosting.h"
#include "semi_loader.h"
static void _print_info(char const **strings)
{
char const *string;
semi_write0("[bootwrapper] ");
while((string = *strings++))
semi_write0(string);
}
#define info(strings...) do { \
char const *__info_strings[] = { strings, NULL }; \
\
_print_info(__info_strings); \
} while(0)
#define warn(strings...) info("WARNING: ", strings)
#define error(strings...) info("ERROR: ", strings)
#define fatal(strings...) do { \
error(strings); \
semi_fatal("[bootwrapper] BOOT FAILED\n"); \
} while(0)
#define CMDLINE_KERNEL "--kernel"
#define CMDLINE_INITRD "--initrd"
#define CMDLINE_NOINITRD "--no-initrd"
#define CMDLINE_DTB "--dtb"
#define CMDLINE_FDT "--fdt" /* deprecated */
#define CMDLINE_REST "-- "
static void _usage_fatal(void)
{
info("Usage: [" CMDLINE_KERNEL " <kernel filename>] ["
CMDLINE_NOINITRD "|" CMDLINE_INITRD " <initrd filename>] ["
CMDLINE_DTB " <dtb filename>] ["
CMDLINE_REST "<kernel boot arguments>]\n");
fatal("Incorrect bootwrapper command-line.\n");
}
#define usage_fatal(strings...) do { \
error(strings); \
_usage_fatal(); \
} while(0)
static void atag_append(void **dest, unsigned tag, void const *data, unsigned size)
{
char *d = *dest;
unsigned padded_size = ALIGN_INT(size, 4) + 8;
struct atag_header header = {
padded_size >> 2,
tag
};
if(tag == ATAG_NONE)
header.size = 0;
memcpy(d, &header, sizeof header);
memcpy(d + 8, data, size);
if(padded_size > size + 8)
memset(d + 8 + size, 0, padded_size - (size + 8));
*dest = d + padded_size;
}
static int _fdt_make_node(void *fdt, int parentoffset, const char *name)
{
int e;
e = fdt_subnode_offset(fdt, parentoffset, name);
if(e != -FDT_ERR_NOTFOUND)
return e;
return fdt_add_subnode(fdt, parentoffset, name);
}
static void _fdt_address_and_size_cells(void *fdt, int *addrcells, int *sizecells)
{
int e;
uint32_t const *p;
if(!(p = fdt_getprop(fdt, 0, "#address-cells", &e)))
goto libfdt_error;
if(e != 4)
goto size_error;
*addrcells = fdt32_to_cpu(*p);
if(!(p = fdt_getprop(fdt, 0, "#size-cells", &e)))
goto libfdt_error;
if(e != 4)
goto size_error;
*sizecells = fdt32_to_cpu(*p);
/*
* Sanity-check address sizes, since addresses and sizes which do
* not take up exactly 4 or 8 bytes are not supported.
*/
if ((*addrcells != 1 && *addrcells != 2) ||
(*sizecells != 1 && *sizecells != 2))
goto size_error;
return;
libfdt_error:
fatal("libfdt: ", fdt_strerror(e), ", while looking for #address-cells/#size-cells\n");
size_error:
fatal("Unexpected/invalid #address-cells/#size-cells in device tree\n");
}
static void update_fdt(void **dest, struct loader_info *info)
{
int e;
int _chosen;
void *fdt;
uint32_t const *p;
int addrcells, sizecells;
if(!info->fdt_start)
return;
fdt = ALIGN(*dest, 4);
if((e = fdt_open_into((void *)info->fdt_start, fdt, FDT_SIZE_MAX)) < 0)
goto libfdt_error;
_fdt_address_and_size_cells(fdt, &addrcells, &sizecells);
/*
* Add a memory node, but only if there isn't one already. If
* there is already a memory node with non-zero size, it was put
* in the DT on purpose and should take precedence over our
* guesses. Otherwise, make a memory node with the appropriate
* parameters.
*/
{
int offset, depth = 0;
int _memory;
uint32_t reg[4];
for(offset = fdt_next_node(fdt, 0, &depth); offset >= 0;
offset = fdt_next_node(fdt, offset, &depth)) {
char const *name;
if(depth != 1)
continue;
name = fdt_get_name(fdt, offset, (void *)0);
if(!strcmp(name, "memory") ||
!strncmp(name, "memory@", 7)) {
p = fdt_getprop(fdt, offset, "reg", &e);
if(e < 0)
goto libfdt_error;
/* Check whether the <size> part of the <addr>,<size> tuple is nonzero */
if(fdt32_to_cpu(p[addrcells]) != 0)
goto no_add_memory;
if(sizecells == 2 && fdt32_to_cpu(p[addrcells + 1]) != 0)
goto no_add_memory;
}
}
if((e = _fdt_make_node(fdt, 0, "memory")) < 0)
goto libfdt_error;
_memory = e;
/* This assumes PHYS_OFFSET and PHYS_SIZE are 32 bits, though
* the fdt cells we put them in may not be.
*/
reg[0] = reg[1] = reg[2] = reg[3] = 0;
reg[addrcells - 1] = cpu_to_fdt32(PHYS_OFFSET);
reg[addrcells + sizecells - 1] = cpu_to_fdt32(PHYS_SIZE);
if((e = fdt_setprop(fdt, _memory, "reg", ®,
sizeof(reg[0]) * (addrcells + sizecells))) < 0)
goto libfdt_error;
if((e = fdt_setprop_string(fdt, _memory, "device_type",
"memory")) < 0)
goto libfdt_error;
}
no_add_memory:
/* populate the "chosen" node */
if((e = _fdt_make_node(fdt, 0, "chosen")) < 0)
goto libfdt_error;
_chosen = e;
e = fdt_setprop_string(fdt, _chosen, "bootargs",
(char const *)info->cmdline_start);
if(e < 0)
goto libfdt_error;
if(info->initrd_start) {
uint32_t initrd_end = info->initrd_start + info->initrd_size;
/* It's not documented whether these cells should honour
* #address-cells. Currently the kernel accepts them as being
* addresses of either size, so we leave them as 32 bits for now.
*/
if((e = fdt_setprop_cell(fdt, _chosen, "linux,initrd-start",
info->initrd_start)) < 0)
goto libfdt_error;
if((e = fdt_setprop_cell(fdt, _chosen, "linux,initrd-end",
initrd_end)) < 0)
goto libfdt_error;
}
/* success */
/* clean up */
fdt_pack(fdt);
info->fdt_start = (unsigned)fdt;
info->fdt_size = fdt_totalsize(fdt);
info("FDT updated.\n");
return;
libfdt_error:
fatal("libfdt: ", fdt_strerror(e), ", while updating device tree\n");
}
/* For accessing 32-bit device ports */
#define io32(p) (*(volatile uint32_t *)(p))
static void init_cci(unsigned cci)
{
info("Initialising CCI\n");
/*
* Ideally, the CCI device tree binding would include suitable
* information so we can correctly configure the CCI, but for
* now we'll just hard-code settings for the present A15xA7
* models.
*/
/* Turn on CCI snoops and DVM messages */
io32(cci+0x4000) = 0x3; /* A15 cluster */
io32(cci+0x5000) = 0x3; /* A7 cluster */
/* Wait while change pending bit of status register is set */
while(io32(cci+0xc) & 0x1)
{}
}
static void configure_from_fdt(struct loader_info *info)
{
void *fdt = (void *)info->fdt_start;
uint32_t const *p;
int addrcells, sizecells;
int offset, len;
if(!fdt)
return;
_fdt_address_and_size_cells(fdt, &addrcells, &sizecells);
/* See if there is a CCI device to initialise */
offset = fdt_node_offset_by_compatible(fdt, 0, "arm,cci");
if (offset >= 0) {
p = fdt_getprop(fdt, offset, "reg", &len);
if(len != (addrcells + sizecells) * 4)
info("Failed parsing device-tree node for CCI\n");
else {
/*
* p[addrcells - 1] is the least significant 32-bits of
* the address for the CCI. On 32-bit CPUs any additional
* address bits had better be zero otherwise we can't
* access it as we don't enable the MMU.
*/
init_cci(fdt32_to_cpu(p[addrcells - 1]));
}
}
return;
}
static int is_space(char c)
{
return c == ' ';
}
static void skip_space(char **s)
{
char *t = *s;
for(t = *s; is_space(*t); t++);
*s = t;
}
static void find_space(char **s)
{
char *t = *s;
for(t = *s; *t && !is_space(*t); t++);
*s = t;
}
static int match_word(char **s, char const *string)
{
unsigned l;
l = strlen(string);
if(strncmp(*s, string, l))
return 0;
*s += l;
skip_space(s);
return 1;
}
/*
* Match an option with a mandatory argument.
* On success, a pointer to the argument is returned, with leading and
* trailing whitespace stripped.
*/
static char *match_option(char **s, char const *option_string)
{
char *arg;
if(!match_word(s, option_string))
return (void *)0;
if(!**s)
usage_fatal("Option requires as argument: ",
option_string, "\n");
/* otherwise, *s now points to the argument */
arg = *s;
find_space(s); /* find the end of the argument */
if(**s) {
*(*s)++ = '\0'; /* null-terminate if necessary */
skip_space(s); /* skip any remaining space */
}
return arg;
}
static void load_file_essential(void **dest, char const *filename,
unsigned *size, char const *failmsg)
{
if(semi_load_file(dest, size, filename))
fatal(failmsg, ": \"", filename, "\"\n");
}
/* is_uboot_image_format - to check an image is in uboot image format or not
* @start: start address of the image
* @size: size of the image
*
* Returns:
* 0: no
* 1: yes
*/
static int is_uboot_image_format(const char *start, const unsigned size)
{
if(size <= UBOOT_IMAGE_HEADER_SIZE)
return 0;
return !memcmp(start, uboot_image_header_magic,
sizeof uboot_image_header_magic);
}
/* Move the kernel if necessary, based on the image type: */
static void correct_kernel_location(struct loader_info *info)
{
char *const text_start = (char *)(PHYS_OFFSET + TEXT_OFFSET);
char *const text_end = text_start + info->kernel_size;
char *const uImage_payload = text_start + UBOOT_IMAGE_HEADER_SIZE;
unsigned long *const zImage_magic_p = (unsigned long *)(
uImage_payload + ZIMAGE_MAGIC_OFFSET);
/*
* If the image is not a uImage, then it is a raw Image or zImage,
* and no action is necessary:
*/
if(!is_uboot_image_format(text_start, info->kernel_size))
return;
warn("Ignoring uImage meta-data\n");
/*
* If the uImage payload is a zImage, the position-independent
* nature of the zImage header means that no relocation is
* needed. Instead, just enter at the start of the loaded
* zImage header:
*/
if(text_end >= (char *)&zImage_magic_p[1]
&& *zImage_magic_p == ZIMAGE_MAGIC) {
info->kernel_entry += UBOOT_IMAGE_HEADER_SIZE;
return;
}
/*
* Otherwise, move the payload to replace the uImage header, and
* leave the entry point unmodified.
*/
memmove(text_start, uImage_payload,
info->kernel_size - UBOOT_IMAGE_HEADER_SIZE);
}
static void correct_initrd_location(struct loader_info *info)
{
/*
* if initrd image is in u-boot image format,
* move initrd_start and initrd_size to ignore the header
*/
if(is_uboot_image_format((char *)info->initrd_start,
info->initrd_size)) {
warn("Ignoring uInitrd meta-data\n");
info->initrd_start += UBOOT_IMAGE_HEADER_SIZE;
info->initrd_size -= UBOOT_IMAGE_HEADER_SIZE;
}
return;
}
static char semi_cmdline[SEMI_CMDLINE_MAX];
static char *kernel_arg = (void *)0;
static char *initrd_arg = (void *)0;
static char *fdt_arg = (void *)0;
static char *dtb_arg = (void *)0;
static char *cmdline_arg = (void *)0;
static char *noinitrd_arg = (void *)0;
static const struct {
char const *option_string;
char **argp;
enum { OPT_ARG, OPT_BOOL, OPT_REST } action;
} options[] = {
{ CMDLINE_KERNEL, &kernel_arg, OPT_ARG },
{ CMDLINE_INITRD, &initrd_arg, OPT_ARG },
{ CMDLINE_NOINITRD, &noinitrd_arg, OPT_BOOL },
{ CMDLINE_FDT, &fdt_arg, OPT_ARG },
{ CMDLINE_DTB, &dtb_arg, OPT_ARG },
{ CMDLINE_REST, &cmdline_arg, OPT_REST },
};
void load_kernel(struct loader_info *info)
{
unsigned i;
char *cmdline = semi_cmdline;
int cmdline_length;
void *phys = (char *)(PHYS_OFFSET + TEXT_OFFSET);
void *atagp = (char *)(PHYS_OFFSET + ATAGS_OFFSET);
union {
struct atag_core core;
struct atag_mem mem;
struct atag_initrd2 initrd;
} atag;
/* Fetch the command line: */
if(semi_get_cmdline(semi_cmdline, sizeof semi_cmdline,
&cmdline_length) ||
cmdline_length >= sizeof semi_cmdline) {
warn("Failed to get semihosting command line, using built-in defaults\n");
cmdline_length = 0;
}
cmdline[cmdline_length] = '\0';
/* Parse the arguments (if any): */
skip_space(&cmdline);
while(*cmdline) {
for(i = 0; i < sizeof options / sizeof *options; i++) {
char *arg;
switch(options[i].action) {
case OPT_BOOL:
if(!match_word(&cmdline,
options[i].option_string))
continue;
*options[i].argp = cmdline; /* non-NULL */
goto next_arg;
case OPT_REST:
if(!match_word(&cmdline,
options[i].option_string))
continue;
*options[i].argp = cmdline;
goto args_done;
case OPT_ARG:
arg = match_option(&cmdline,
options[i].option_string);
if(!arg)
continue;
if(*options[i].argp)
usage_fatal("Duplicate option ",
options[i].option_string);
/* otherwise, option was parsed successfully: */
*options[i].argp = arg;
goto next_arg;
}
} /* for(i) */
/* Failed to match any expected option: */
usage_fatal("Invalid option(s): ", cmdline);
next_arg: ;
} /* while(*cmdline) */
args_done:
if(initrd_arg && noinitrd_arg)
usage_fatal("Option --initrd conflicts with --no-initrd.\n");
if(fdt_arg) {
warn("--fdt is deprecated. Please use --dtb instead.\n");
if(dtb_arg)
usage_fatal("--fdt conflicts with --dtb.\n");
else
dtb_arg = fdt_arg;
}
/*
* Now, proceed to load images and set up ATAGs.
* For simplicity, ATAGs are generated even if there is a DTB
*/
/* built-in FDT not supported, for now */
info->fdt_start = info->fdt_size = 0;
info->atags_start = (unsigned)atagp;
memset(&atag.core, 0, sizeof atag.core);
atag_append(&atagp, ATAG_CORE, &atag.core, sizeof atag.core);
/* create the essential ATAGs */
atag.mem.start = PHYS_OFFSET;
atag.mem.size = PHYS_SIZE;
atag_append(&atagp, ATAG_MEM, &atag.mem, sizeof atag.mem);
/* load the kernel */
info->kernel_entry = (unsigned)phys;
if(kernel_arg) {
load_file_essential(&phys, kernel_arg, &info->kernel_size,
"Failed to load kernel image");
info("Loaded kernel: ", kernel_arg, "\n");
} else if(info->kernel_size) {
info("Using built-in kernel\n");
phys += info->kernel_size;
} else
usage_fatal("Expected " CMDLINE_KERNEL "\n");
/* move the kernel to the correct place, if necessary */
correct_kernel_location(info);
phys = (char *)(PHYS_OFFSET + INITRD_OFFSET);
/* load the initrd */
atag.initrd.size = 0;
if(initrd_arg) {
unsigned start = (unsigned)phys;
load_file_essential(&phys, initrd_arg, NULL,
"Failed to load initrd image");
info("Loaded initrd: ", initrd_arg, "\n");
info->initrd_start = start;
info->initrd_size = (unsigned)phys - start;
correct_initrd_location(info);
atag.initrd.start = info->initrd_start;
atag.initrd.size = info->initrd_size;
} else if(info->initrd_size) {
if(noinitrd_arg) {
info->initrd_size = 0;
info("Built-in initrd discarded, as requested\n");
} else {
info("Using built-in initrd\n");
atag.initrd.start = info->initrd_start;
atag.initrd.size = info->initrd_size;
}
} else
info->initrd_size = 0;
if(atag.initrd.size)
atag_append(&atagp, ATAG_INITRD2, &atag.initrd, sizeof atag.initrd);
/* load the FDT, if specified */
if(dtb_arg) {
phys = ALIGN(phys, 4);
info->fdt_start = (unsigned)phys;
load_file_essential(&phys, dtb_arg, NULL,
"Failed to load device tree blob");
info("Loaded FDT: ", dtb_arg, "\n");
info->fdt_size = (unsigned)phys - info->fdt_start;
}
/*
* The FDT will get modified to reflect bootargs, initrd and memory
* configuration later.
*/
/* set the command line */
if(cmdline_arg) {
info->cmdline_start = (unsigned)cmdline_arg;
info->cmdline_size = strlen(cmdline_arg) + 1;
} else if(info->cmdline_size)
info("Using built-in kernel bootargs\n");
/* cmdline_size is presumed to include a NUL terminator: */
if(info->cmdline_size) {
atag_append(&atagp, ATAG_CMDLINE,
(char *)info->cmdline_start, info->cmdline_size);
info("Kernel bootargs: ", (char *)info->cmdline_start, "\n");
}
atag_append(&atagp, ATAG_NONE, 0, 0);
update_fdt(&phys, info);
configure_from_fdt(info);
}