PSPboot is the successor of adam2 but only slightly backwards compatible with it. See Adam2_versus_PSP_bootloader. It is the bootloader used e.g. on the Linksys WAG354G, WRTP54G and ADSL2MUE as well as the https://oldwiki.archive.openwrt.org/toh/netgear/sc101.
Here is the user guide of PSPBoot version 1.2:
What the guide is not saying is that the “boot” command supports placing a kernel command line. Every argument after “boot” gets passed.
free space start: 0xb0020000 free space end: 0xb0400000 Minimal POST completed... Success. Last reset cause: Hardware reset (Power-on reset) PSPBoot1.2 rev: 0.22.17 (c) Copyright 2002-2004 Texas Instruments, Inc. All Rights Reserved. FlashType: mac_init(): Find mac [00:13:10:F9:E2:CE] in location 0 Find mac [00:13:10:F9:E2:CE] in location 0 mac_value: 00:13:10:F9:E2:CE Press ESC for monitor... 1 (psbl)
(psbl) help reboot version info fa printenv setenv unsetenv defragenv fmt boot dm oclk help
(psbl) help reboot reboot: Warm reboot the system (psbl) help version version: Dump build information and optional modules supported (psbl) help info info: Gives SoC specific information. (psbl) help fa fa: Displays flash allocation information (psbl) help printenv printenv: Print all configured system environment variables. Usage: printenv [envlist] (psbl) help setenv setenv: Set a system environment variable (psbl) help unsetenv unsetenv: Delete a system environment variable (psbl) help defragenv defragenv: Defragment the system environment space (psbl) help fmt fmt: Erase a given area on Flash memory Usage: fmt -a fmt (psbl) help boot boot: Boot the OS image according to settings in 'BOOTCFG' (psbl) help dm dm: Dump memory from a given address Usage: dm [ [num words]] (psbl) help oclk oclk: Configure/Dump the frequencies for CPU and System
(psbl) version PSPBoot 126.96.36.199 Compiled gcc rev: 2.95.3 20010315 (release/MontaVista) [May 17 2005 18:36:51] Built for AR7WRD board in Little Endian mode. Optional modules included (+) or not (-): +tibinary -elf -gzip -ffs -tftp -ftp -dhcp -pcapp (psbl) boot boot order: f boot file: mtd1
(psbl) info CHIP ID: TNETD73XX (0x5), REV: 0x21 MIPS Processor : 4KEc rev: 2.2.0 Cache mode : write-back, write-allocate. Instruction cache: Associativity: 4, Line size: 16, Total size: 16KB Data cache : Associativity: 4, Line size: 16, Total size: 16KB Last reset cause: Software reset (memory controller also reset) EMIF is running at the same speed of the processor. Processor running in little endian mode. Processor clock is asynchronous to internal bus clock.
(psbl) printenv bootloaderVersion 188.8.131.52 ProductID AR7WRD HWRevision Unknown SerialNumber none IPA 192.168.1.1 MAC_PORT 1 SwRev 0.22.17 MEMSZ 0x1000000 FLASHSZ 0x400000 MODETTY0 38400,n,8,1,hw MODETTY1 38400,n,8,1,hw CPUFREQ 150000000 SYSFREQ 125000000 PROMPT (psbl) mtd0 0x900e0000,0x903f0000 mtd1 0x90020000,0x903f0000 mtd2 0x90000000,0x90020000 mtd3 0x903f0000,0x90400000 mtd4 0x90020000,0x903f0000 pair_selection 0 HWA_0 00:13:10:F9:E2:CE BOOTCFG m:f:mtd1
(psbl) fa Current Flash Allocation: section : PSBL, base : 0xb0000000, size : 51616 bytes section : ENV, base : 0xb0010000, size : 65536 bytes unallocated Space Start: 0xb0020000 unallocated Space End : 0xb0400000
PSPBoot accepts a TFTP upload of a new firmware while beeing in command line mode or during the boot wait. The boot wait is 3 seconds by default. This creates a very narrow windows for uploading. TFTP is possible at about 2 seconds after powerup for about 1 second.
With a serial console attached, it is also possible to stop the boot process by pressing ESC. The bootloader will then continue to accept uploads. The uploaded file has to be called upgrade_code.bin .
Without serial console, this procedure was successful on wag354g:
tftp> verbose (for debugging purpose) tftp> trace ( " " " ) tftp> rexmt 1 tftp> timeout 5 tftp> binary tftp> connect 192.168.1.1
tftp> put upgrade_code.bin
If transfer starts, the tftp output is like this:
.... sent DATA received ACK ...