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zig-mtd/update-uboot.zig

74 lines
2.1 KiB
Zig

const std = @import("std");
const math = std.math;
const mtd_user = @cImport(@cInclude("mtd/mtd-user.h"));
const uboot = @embedFile("uboot-feb2019.bin");
const mtd_rw = @import("mtd-rw.zig");
const Allocator = std.heap.c_allocator;
fn mtd_info_get(name: []const u8, out: []u8) !void {
var path_buf: [64]u8 = undefined;
const path = try std.fmt.bufPrint(path_buf[0..], "{}/{}", .{"/sys/class/mtd/mtd0/", name});
var f = try std.fs.openFileAbsolute(path, .{.read = true});
defer f.close();
const num_read = try f.read(out);
out = out[0..num_read-1];
}
fn mtd_info_get_usize(name: []const u8) !usize {
var buf: [64]u8 = undefined;
var buf_sl = buf[0..];
try mtd_info_get(name, buf_sl);
return try std.fmt.parseUnsigned(usize, buf_sl, 10);
}
pub fn main() !u8 {
try mtd_rw.load();
defer mtd_rw.unload();
// Read and hash mtd0
const mtd0_size = try mtd_info_get_usize("size");
if (uboot.len > mtd0_size) {
std.debug.warn("Error: mtd0 isn\'t large enough to hold the new image ({} > {})\n",
.{uboot.len, mtd0_size});
return 1;
}
var current_uboot = try Allocator.alloc(u8, mtd0_size);
var f = try std.fs.openFileAbsolute("/dev/mtd0", .{.read = true});
defer f.close();
const num_read = try f.read(current_uboot[0..]);
if (num_read != mtd0_size) {
std.debug.warn("Failed to read /dev/mtd0", .{});
return 2;
}
var current_digest: [std.crypto.Md5.digest_length]u8 = undefined;
std.crypto.Md5.hash(current_uboot, current_digest[0..]);
// Compare against payload
var embedded_digest: [std.crypto.Md5.digest_length]u8 = undefined;
std.crypto.Md5.hash(uboot, embedded_digest[0..]);
if (std.mem.eql(u8, current_digest[0..], embedded_digest[0..])) {
std.debug.warn("U-Boot is up to date. Exiting.\n", .{});
return 0;
}
// Erase mtd0
const mtd0_erasesize = try mtd_info_get_usize("erasesize");
var erased = 0;
while (erased < mtd0_size) {
//erase page
erased += mtd0_erasesize;
}
// Write mtd0
// Verify mtd0
std.debug.warn("Done\n", .{});
return 0;
}