u-boot：盡管 kernel 小於最大 BOOTM_LEN，但無法啟動 linux kernel

Question

我有一個帶有 u-boot 的 MIPS 系統 (VSC7427)，我正在嘗試引導比供應商在其 GPL 版本中提供的 kernel 更新的 kernel （ 啟動得很好）。

kernel FIT 圖像看起來很正常，從 output 來看，我認為它應該是可引導的：

U-Boot 2019.10 (Mar 28 2021 - 20:41:55 +0000)

MSCC VCore-III MIPS 24Kec
Model: Cisco Meraki MS220-8P
DRAM:  128 MiB
Loading Environment from SPI Flash... SF: Detected mx25l12805d with page size 256 Bytes, erase size 64 KiB, total 16 MiB
OK
In:    serial@10100000
Out:   serial@10100000
Err:   serial@10100000
Net:   
Warning: switch@1010000 (eth0) using random MAC address - b2:6b:53:af:2d:a0
eth0: switch@1010000
luton # dhcp
(snipped)
luton # tftp vmlinux.gz.itb
Using switch@1010000 device
TFTP from server 192.168.1.60; our IP address is 192.168.1.154
Filename 'vmlinux.gz.itb'.
Load address: 0x80100000
Loading: #################################################################
(snipped)
done
Bytes transferred = 5172244 (4eec14 hex)
luton # iminfo 0x80100000

## Checking Image at 80100000 ...
   FIT image found
   FIT description: Linux 5.11.11
    Image 0 (kernel@0)
     Description:  Linux 5.11.11
     Type:         Kernel Image
     Compression:  gzip compressed
     Data Start:   0x801000c0
     Data Size:    5167511 Bytes = 4.9 MiB
     Architecture: MIPS
     OS:           Linux
     Load Address: 0x80100000
     Entry Point:  0x809898f4
     Hash algo:    sha1
     Hash value:   b963ed48f45e332bd5df263dd69d69c3818e6586
    Image 1 (fdt@luton_pcb091)
     Description:  MSCC Luton PCB091 Device Tree
     Type:         Flat Device Tree
     Compression:  uncompressed
     Data Start:   0x805edb60
     Data Size:    2851 Bytes = 2.8 KiB
     Architecture: MIPS
     Hash algo:    sha1
     Hash value:   5283ae4322294e594a7be5e6de65e4f039ff36a5
    Default Configuration: 'conf@default'
    Configuration 0 (conf@default)
     Description:  Generic Linux kernel
     Kernel:       kernel@0
    Configuration 1 (pcb091)
     Description:  Luton Linux kernel
     Kernel:       kernel@0
     FDT:          fdt@luton_pcb091
## Checking hash(es) for FIT Image at 80100000 ...
   Hash(es) for Image 0 (kernel@0): sha1+ 
   Hash(es) for Image 1 (fdt@luton_pcb091): sha1+

但是，當我嘗試啟動 kernel 時，u-boot 會出現以下錯誤：

luton # bootm 0x80100000
## Loading kernel from FIT Image at 80100000 ...
   Using 'conf@default' configuration
   Trying 'kernel@0' kernel subimage
     Description:  Linux 5.11.11
     Type:         Kernel Image
     Compression:  gzip compressed
     Data Start:   0x801000c0
     Data Size:    5167511 Bytes = 4.9 MiB
     Architecture: MIPS
     OS:           Linux
     Load Address: 0x80100000
     Entry Point:  0x809898f4
     Hash algo:    sha1
     Hash value:   b963ed48f45e332bd5df263dd69d69c3818e6586
   Verifying Hash Integrity ... sha1+ OK
   Uncompressing Kernel Image
Error: inflate() returned -3
gzip compressed: uncompress error -1
Must RESET board to recover

kernel 的大小遠低於CONFIG_SYS_BOOTM_LEN (16MB) 定義的限制，因此我認為這不是此錯誤的根本原因。

用於生成itb的vmlinux.bin.gz是一個有效的 gzip 存檔，並且解壓后的大小也小於CONFIG_SYS_BOOTM_LEN限制：

$ file vmlinux.bin.gz
vmlinux.bin.gz: gzip compressed data, max compression, from Unix, original size modulo 2^32 11494800

我嘗試使用未壓縮的vmlinux.bin創建itb文件（我只是將vmlinux.its編輯為具有data = /incbin/("vmlinux.bin");和compression = "none";以及由readelf -h vmlinux ) 但我在嘗試啟動時收到以下錯誤：

luton # bootm ${loadaddr}
## Loading kernel from FIT Image at 80100000 ...
   Using 'conf@luton_pcb091' configuration
   Trying 'kernel@0' kernel subimage
     Description:  Linux 5.11.0
     Type:         Kernel Image
     Compression:  uncompressed
     Data Start:   0x801000c0
     Data Size:    11584912 Bytes = 11 MiB
     Architecture: MIPS
     OS:           Linux
     Load Address: 0x80100000
     Entry Point:  0x809898f4
     Hash algo:    sha1
     Hash value:   d13175476fd38269a02a3e85bef53419092c01e1
   Verifying Hash Integrity ... sha1+ OK
## Loading fdt from FIT Image at 80100000 ...
   Using 'conf@luton_pcb091' configuration
   Trying 'fdt@luton_pcb091' fdt subimage
     Description:  img,luton_pcb091 Device Tree
     Type:         Flat Device Tree
     Compression:  uncompressed
     Data Start:   0x80c0c758
     Data Size:    2303 Bytes = 2.2 KiB
     Architecture: MIPS
     Hash algo:    sha1
     Hash value:   daa8a8147bbce692d81383af7b748a763212bb24
   Verifying Hash Integrity ... sha1+ OK
   Booting using the fdt blob at 0x80c0c758
   Loading Kernel Image
ERROR: new format image overwritten - must RESET the board to recover

查看common/bootm.c bootm_load_os的 bootm_load_os 似乎這個錯誤告訴我，我正在嘗試引導的 kernel 之間存在一些重疊......有些東西，我不確定是什么。

這是由 kernel 5.11 生成的vmlinux.its ：

/* SPDX-License-Identifier: GPL-2.0 */
/dts-v1/;
/ {
 description = "Linux 5.11.11";
 #address-cells = <1>;
 images {
  kernel@0 {
   description = "Linux 5.11.11";
   data = /incbin/("vmlinux.bin.gz");
   type = "kernel";
   arch = "mips";
   os = "linux";
   compression = "gzip";
   load = /bits/ 32 <0xffffffff80100000>;
   entry = /bits/ 32 <0xffffffff809898f4>;
   hash@0 {
    algo = "sha1";
   };
  };
 };
 configurations {
  default = "conf@default";
  conf@default {
   description = "Generic Linux kernel";
   kernel = "kernel@0";
  };
 };
};
/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
/ {
 images {
  fdt@luton_pcb091 {
   description = "MSCC Luton PCB091 Device Tree";
   data = /incbin/("boot/dts/mscc/luton_pcb091.dtb");
   type = "flat_dt";
   arch = "mips";
   compression = "none";
   hash@0 {
    algo = "sha1";
   };
  };
 };
 configurations {
  pcb091 {
   description = "Luton Linux kernel";
   kernel = "kernel@0";
   fdt = "fdt@luton_pcb091";
  };
 };
};

binwalk並不表示 ITB 中的gzip數據無效：

$ binwalk vmlinux.gz.itb 

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
0             0x0             device tree image (dtb)
192           0xC0            gzip compressed data, maximum compression, from Unix, last modified: 1970-01-01 00:00:00 (null date)
3960903       0x3C7047        MySQL ISAM compressed data file Version 10
5167968       0x4EDB60        device tree image (dtb)

mkimage version 2020.01由 buildroot 作為host-uboot-tools-2020.01一部分構建

---

根據 Tom Rini 的建議，我更改了 FIT 映像的 loadaddr 並且不再收到uncompress錯誤，但是系統似乎仍然無法啟動。 我已將此移至后續問題。

Answer 1

您遇到的最后一個問題：

錯誤：新格式圖像被覆蓋 - 必須重置板才能恢復

是因為您已將映像加載到 memory 與入口點相同的位置，但您需要將其加載到 memory 其他地方，以便 U-Boot 可以解壓縮映像並將內容放入其加載地址設置為. 由於您有 128MB 的 memory，您應該能夠從一開始就將其設置為 +32 或 +64MB，然后一切正常。