SD Card and RiscOS

Hello

I read that

SD cards are optimized for sequential read and write. They are designed to read or write one file at a time, and that’s great for cameras (what they were designed to be used in), but terrible for a computer OS that frequently bounces all over, reading and writing many files in different places (which crushes SD card performance).

I am wondering how true this is for RiscOS. Does RiscOS perform that many read/write “in the background” that would evently corrupt the SD card sooner or later? What would be a solution for Raspberry Pi? There exist a PiDesktop
case providing for a mSata extension. Is it possible to configure RiscOS to boot from a SSD mSata hard drive in that case?

Thank you.

François

Yes, it is possible to configure RISCOS to boot from mSATA (or SSD or HDD).

Just search the forums for mSATA to see plenty of discussion about it.

All Pi mSATA/SATA drives are connected via USB which uses SCSI. So you have to set the boot filesystem to SCSI.

Hi

I am struggling configuring my RaspBi 3B to boot from an usb external hardrive.
Here are the steps done so far:
1) Format a SD card in Fat32
2) Copy the following files at the root of the SDCard:bootcode.bin, config.txt, fixup.dat, riscos.img (v. 5.24) start.elf and cmos
3) Format the usb external hard drive with HForm
4) Copy the ciontent of HardDisc4/5/24/zip at the root of the external hard drive
5) update config.txt as follow:

fake_vsync_isr=1
framebuffer_swap=0
gpu_mem=64
disable_overscan=1
init_emmc_clock=100000000
ramfsfile=CMOS
ramfsaddr=0×508000
kernel=RISCOS.IMG
program_usb_boot_mode=1

6) reboot my raspberry.

I get a black screen with a blinking cursor. pressing Esc twice lead me to thetask console with the RiscOS splash screen. Then, what should i do?
I tried things like

*Configure filesystem scsi
*Configure scsifsdrive 5
* scsi
* opt 5,2

then reboot, without success.
Could so help me finalising this?
Thank you very much
François

Presumable at the blinking cursor *Desktop takes you to the desktop.

Are you sure the external hard drive is 5 and not 4? In any case it should be *opt4 2

sorry, it is 4, but event with 4 it does not work.

typing Desktop lead me to the desktop with an “empty disk” error :/

Regards

That’s normal if the boot disc is configured wrong.

Does *status show

Boot 
FileSystem SCSI
SCSIFSDrive 4

After formatting the USB HDD with HFORM and copying the Hd4stuff over, look at the SCsI drive number (icn bar menu over drive icon). What SCSI::n number is it?

Hello

So, the external usb drive is defined as SCSI::4
Just after reboot, I reach a black screen with a blinking ‘_’ in the very top-left.
Typing on the keyboard does not display anything on screen.
Pressing ESC twice, brings me to the RiscOS splach screen with the task console displayed in the bottom of the screen, middle-centered.
Type *status shows many lines, including

SCSFSDrive 0
SDFSDrive 0

I cannot find FileSystem in the list, though.

Then trying this

*Configure filesystem scsi
* Configure scsifsdrive 4
* scsi
* opt 4 2

generates the error message The disc drive is empty

What should I do next?

Thank you

François

It looks like it’s not saving to cmos.

The easiest solution is to put the Pi disc image that ROOL supply on the SD card with !SDCreate or Win32DiscImager on windows then with the computer working configure filesystem to SCSI and SCSIFSDrive to 4.

Hello

I got a little further doing the following

*configure filesystem scsi
*configure scsifsdrive 4
*dir scsi::4.$
*opt 4,2
*!boot

this brings me to the desktop, still with the error

Machine startup has not completed successfully: ‘The disc drive is empty’

But at list I can now open the configure window from the raspberry menu.

Where should I save the CMOS file?

Cheers

You don’t save it anywhere. It is one of the files you copied over to the root directory of the SD card – the same directory as the RISC OS rom image. It gets saved to automatically.

typing *!boot doesn’t do any good. When booting RISC OS looks for !boot on the configured drive on the configured filesystem so it’s looking for SDFSDrive 0 on filesystem SDFS which isn’t a RISCOS filesystem.

How are you restarting after setting the values are you shutting down properly or just removing the power?

ramfsaddr=0×508000

That should be a lower case letter x, ASCII 120, not a multiplication symbol, ASCII 215

ramfsaddr=0×508000 wrong
ramfsaddr=0x508000 right

That should be a lower case letter x, ASCII 120, not a multiplication symbol, ASCII 215

A rule for anybody new around here – do not cut and paste from the forum unless the code is in monospace font with a lighter grey background…

[ like this ]

Why? Because Textile horribly messes things up. 0×40 is no longer lowercase ‘X’ even though that’s what was written. “Quotes” are no longer simple quotes. Dash-greaterthan (used for indication in C) becomes → and stuff with multiple underscores (a good number of CLib functions) can be randomly italicised. Oh, and a number in a square bracket ¹² (also used in C) will become a footnote reference as indicated. And that’s just the stuff I remember.

In short, if it’s not a monospaced text on a light grey background as shown above, assume the code or reference is broken. And if it is… well, it’s Textile, assume it is therefore less broken. ;-)

Hello

I have save the CMOS through the CMOS->Save menu in the Configuration window after having configured the screen resolution and keyboard.

Having done the above manipulations, every time i reboot, I reach the black screen, double press ESC to get to the splach screen with the task console and simply type

dir scsi::4.$
!boot

to complete the boot sequence and lauch the desktop with the right screen resolution and keyboard. But I still get the message

Machine startup has not completed successfully: ‘The disc drive is empty’

Apart from that the system is running properly.

So, two things need to be fixed:
> after the system has booted from the sd card, how to switch automatically on the external hard drive to complete the boot sequence?
> how ro get rid off the error message when entering into the desktop;

cheers

François

It’s the same thing that has always needed fixing.

Does *status show filesystem SCSI?

if not after *configure filesystem SCSI does *status show filesystem SCSI?

If not there is something else wrong.

If it does, shutdown the computer at the switcher and restart.

After restart does *status does it show *filesystem SCSI?

If not something else is wrong.

What did you use to format the FAT card?

The following comments spring to mind:-

It looks like the SD card format is OK, or it would not get this far.

When you formatted the usb external hard drive with HForm, did you select that the drive should be bootable? I suspect not.

When you get to the command prompt, type *. and tell us what the first line of the output is. That will tell us where to go next.

program_usb_boot_mode=1

That line was not required for what you are trying to do.

The term ‘boot’ is used twice with RISCOS on a Raspberry Pi. In the context of all of the posts above, it referes to the starting up of RISCOS.

However, before we get to RISCOS, the Rapsberry Pi has to do a hardware ‘boot’ from the files you copied on to the SDCARD (bootcode.bin, RISCOS.IMG, etc). It is possible to tell a Ras Pi 3 to work without an SDCARD and to do this primary hardware boot (using the same files) from a USB device. Hence program_usb_boot_mode=1.

Another challenge, altogether.

That said, even though you have told it to work without an SDCARD, if it finds one it will use it.

Worth pointing out the obvious catch 22 and its warning. You must boot from an SD card to set the USB boot option. Then you can no longer boot from SD.

Before a Raspberry Pi 3 will boot from a mass storage device, it needs to be booted from an SD card with a config option to enable USB boot mode. This will set a bit in the OTP (One Time Programmable) memory in the Raspberry Pi SoC that will enable booting from a USB mass storage device. Once this bit has been set, the SD card is no longer required. Note that any change you make to the OTP is permanent and cannot be undone.

(my emphasis)

https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/msd.md

Hang on there. The Pi 3 will boot from SD card just fine afterwards. I set it shortly after it was announced with no issue. Sure, you can’t switch it off again. I’ve never even bothered trying it except a few days ago with the old ATA HDD. I do remember confirming that I did set the flag though.

Hello,

I finally get it working. The reasonwas probably a defective sd card… or the fact that Fat32 is not recognized by RiscOS. So, I found a 2GB sd card that I formatted in Fat and kt worked.

I am writing a step by step guide I will append to this thread later.

Thanks to all for the help.

Regards

François

Hello

After a few days running RiscOS from an external usb HD and Raspberry Pi 3B, I give up! The performance drop is absolutely dramatic, making daily usage impossible. TO give you an idea, printing to PDF a three pages OvationPro documents (two column layouts and embedded images) using PrintPDF and PDF3 driver takes a few seconds when running from an SD Card and… 2.5 minutes when running from an usb hard drive (at best 5400 rpm, maybe 4400) :/.

So, I am really reconsidering my project to invest into a RaspBerry 3B+ with a mSata HD plugged to the appropriate extension. Considering this extension is plugged over USB, I am wondering what could be the real performance. Will it be closer to a SD Card or an USB external drive?

Any idea?

Thank you.

François

Will it be closer to a SD Card or an USB external drive?

There are some benchmarks for different mSATA solutions here if that helps. It’s worth noting that PiSSDup is actually faster that this on the Pi 3b+

You can compare them with the authoritative benchmarks that Chris Hall publishes.

The performance drop is absolutely dramatic…. when running from a usb hard drive.

Not looked at performance with a real hard drive, but with SSD (or mSATA) there is no noticeable drop. (I have done any formal testing, but the Pi certainly feels better.

And it will be more reliable for long term use.

I have just tried a SATA drive (Crucial BX100 120GB drive using Crucial USB adapter) on my Pi3B+ and get about 30MB/s load/save but 400kB/s get/put so that may explain poor performance when copying or writing using OS_GBPB rather than load/save.

Class 10 SD card Load/Save/Read/Write is 23MB/s 8MB/s 1024kB/s 325kB/s
LanMan98/NAS is 23MB/s 15MB/s 1575kB/s 650kB/s
120GB SATA via USB is 25MB/s 29MB/s 420kB/s 420kB/s

So faster than a class 10 SD card (SD cards do vary a lot though, some class 10 cards are poor at non-sequential access) except for reading bytes. Only marginally faster for writing bytes but quite a bit faster for file saves (the Crucial drive has RAM buffering).