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Refactor dtb in rust

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This commit is contained in:
LoveSy
2023-09-19 00:12:49 -07:00
committed by John Wu
parent 8e1a91509c
commit 8d7c7c3dfb
14 changed files with 403 additions and 626 deletions
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53
native/src/boot/bootimg.cpp
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@@ -1,7 +1,7 @@
#include <bit>
#include <functional>
#include <memory>
#include <libfdt.h>
#include <base.hpp>
#include "boot-rs.hpp"
@@ -183,29 +183,70 @@ boot_img::~boot_img() {
delete hdr;
}
struct [[gnu::packed]] fdt_header {
struct fdt32_t {
uint32_t byte0: 8;
uint32_t byte1: 8;
uint32_t byte2: 8;
uint32_t byte3: 8;
constexpr operator uint32_t() const {
return bit_cast<uint32_t>(fdt32_t {
.byte0 = byte3,
.byte1 = byte2,
.byte2 = byte1,
.byte3 = byte0
});
}
};
struct node_header {
fdt32_t tag;
char name[0];
};
fdt32_t magic; /* magic word FDT_MAGIC */
fdt32_t totalsize; /* total size of DT block */
fdt32_t off_dt_struct; /* offset to structure */
fdt32_t off_dt_strings; /* offset to strings */
fdt32_t off_mem_rsvmap; /* offset to memory reserve map */
fdt32_t version; /* format version */
fdt32_t last_comp_version; /* last compatible version */
/* version 2 fields below */
fdt32_t boot_cpuid_phys; /* Which physical CPU id we're
booting on */
/* version 3 fields below */
fdt32_t size_dt_strings; /* size of the strings block */
/* version 17 fields below */
fdt32_t size_dt_struct; /* size of the structure block */
};
static int find_dtb_offset(const uint8_t *buf, unsigned sz) {
const uint8_t * const end = buf + sz;
for (auto curr = buf; curr < end; curr += sizeof(fdt_header)) {
curr = static_cast<uint8_t*>(memmem(curr, end - curr, DTB_MAGIC, sizeof(fdt32_t)));
curr = static_cast<uint8_t*>(memmem(curr, end - curr, DTB_MAGIC, sizeof(fdt_header::fdt32_t)));
if (curr == nullptr)
return -1;
auto fdt_hdr = reinterpret_cast<const fdt_header *>(curr);
// Check that fdt_header.totalsize does not overflow kernel image size
uint32_t totalsize = fdt32_to_cpu(fdt_hdr->totalsize);
uint32_t totalsize = fdt_hdr->totalsize;
if (totalsize > end - curr)
continue;
// Check that fdt_header.off_dt_struct does not overflow kernel image size
uint32_t off_dt_struct = fdt32_to_cpu(fdt_hdr->off_dt_struct);
uint32_t off_dt_struct = fdt_hdr->off_dt_struct;
if (off_dt_struct > end - curr)
continue;
// Check that fdt_node_header.tag of first node is FDT_BEGIN_NODE
auto fdt_node_hdr = reinterpret_cast<const fdt_node_header *>(curr + off_dt_struct);
if (fdt32_to_cpu(fdt_node_hdr->tag) != FDT_BEGIN_NODE)
auto fdt_node_hdr = reinterpret_cast<const fdt_header::node_header *>(curr + off_dt_struct);
if (fdt_node_hdr->tag != 0x1u)
continue;
return curr - buf;