Rick's b.log - entry 2016/03/26

RISC OS source mods - 2016

Turn off ZPP and use RISC OS the old-fashioned way

Open the file ..xxx.BuildSys.Components.ROOL.xxx where 'xxx' (both times) is the one relative to your build, OMAP3, BCM2835, or whatever.

A little ways down in the file, you will see this:

Kernel        -at 0xFFC010000 -options ASFLAGS="-PD \"CMOS_Override SETS \\\"= FileLangCMOS,fsnumber_SDFS,CDROMFSCMOS,&C0\\\"\""

Change this to specify HiProcVecs as FALSE. Note that this will probably be wrapped on your browser so it fits, the first line begins #Kernel and is a commented out version of the original (above). The second line begins "Kernel" and is the one the build process will be using.

#Kernel        -at 0xFFC010000 -options ASFLAGS="-PD \"CMOS_Override SETS \\\"= FileLangCMOS,fsnumber_SDFS,CDROMFSCMOS,&C0\\\"\""
Kernel        -at 0xFFC010000 -options ASFLAGS="-PD \"HiProcVecs SETL {FALSE}\" -PD \"CMOS_Override SETS \\\"= FileLangCMOS,fsnumber_SDFS,CDROMFSCMOS,&C0\\\"\""

That again, in tiny text just so it's clear that this is only two lines:

#Kernel        -at 0xFFC010000 -options ASFLAGS="-PD \"CMOS_Override SETS \\\"= FileLangCMOS,fsnumber_SDFS,CDROMFSCMOS,&C0\\\"\""
Kernel        -at 0xFFC010000 -options ASFLAGS="-PD \"HiProcVecs SETL {FALSE}\" -PD \"CMOS_Override SETS \\\"= FileLangCMOS,fsnumber_SDFS,CDROMFSCMOS,&C0\\\"\""

Then a little further down you will see:

FPEmulator    -options FPE_APCS=3/32bit FPEANCHOR=High

Change this to:

#FPEmulator    -options FPE_APCS=3/32bit FPEANCHOR=High
FPEmulator    -options FPE_APCS=3/32bit

As with the Kernel entry, the original FPEmulator entry is kept, but is prefixed '#' to comment it out. This is in case you want to build a ZPP version of RISC OS. Simply load this file, switch which entries are commented, and rebuild FPEmulator and the Kernel (and probably the HAL just in case), then make a new ROM.

• RISC OS aborts, freezes, or otherwise dies horribly as it initialises? Ensure that FPEANCHOR=High is specified for the ZPP build, and that it is not for the Page Zero build. Getting FPEmulator out of sync with the kernel will cause system initialisation to fail.

Add CET/CEST to UK territory

Here's how to add CET and CEST. For other anglophones (Japan, New Zealand, etc), feel free to replace CET and CEST with your own timezone names and offsets. In the file ...castle.RiscOS.Sources.Internat.Territory.Module.s.UK, change line 55 from:

MaxTZLength     *       3       ; "GMT"

MaxTZLength     *       4       ; "CEST"

Then change from line 61 from:

NumberOfTZ      *       1

        GBLS    NODST0
NODST0  SETS    "GMT"

        GBLS    DST0
DST0    SETS    "BST"

NODSTOffset0    *       100*60*60*0     ; Zero hours
DSTOffset0      *       100*60*60*1

NumberOfTZ      *       2

        GBLS    NODST0
NODST0  SETS    "GMT"

        GBLS    DST0
DST0    SETS    "BST"

NODSTOffset0    *       100*60*60*0     ; Zero hours
DSTOffset0      *       100*60*60*1

        GBLS    NODST1
NODST1  SETS    "CET"

        GBLS    DST1
DST1    SETS    "CEST"

NODSTOffset1    *       100*60*60*1
DSTOffset1      *       100*60*60*2

Fix CLib's broken localtime()

I find it amusing that ROOL decide to implement ZPP which risks compatibility issues with (buggy) software that may never be updated again, yet something so obviously broken as this requires a bunch of regression tests to be performed on systems that aren't even capable of correctly dealing with timezones in user loaded territories. I have not (yet) performed such testing as I'm not entirely certain what I'm supposed to be testing... Anyway, we can do something about this: Starting from line 257 of ...castle.RiscOS.Sources.Lib.RISC_OSLib.c.time, change:

    territory = __locales[N_LC_TIME];
    if (!territory) {
        r.r[0] = -1; /* If C locale use current configured territory */
    } else {
        r.r[0] = TERRITORY_EXTRACT(territory);
        r.r[1] = TERRITORY_TZ_EXTRACT(territory);
        r.r[4] = TERRITORY_TZ_API_EXT; /* If not supported, never mind */
    }
    if (_kernel_swi(Territory_ReadTimeZones, &r, &r) == NULL) {
        v = (dst == 0x8000) ? r.r[3] : r.r[2];
        t += v / 100; /* centiseconds -> seconds */
    }

    territory = __locales[N_LC_TIME];

    if ( !territory )
    {
        // If C locale, use the currently configured timezone
        // of the currently configured territory
        r.r[2] = 0; // make sure it does not say "ZONE"
        _kernel_swi(Territory_ReadCurrentTimeZone, &r, &r); // ##TODO## Should check for errors! ;-)
        t += (r.r[1] / 100); // centiseconds -> seconds
    }
    else
    {
        // Custom locale - work it out from the specified
        // timezone and DST setting
        r.r[0] = TERRITORY_EXTRACT(territory);
        r.r[1] = TERRITORY_TZ_EXTRACT(territory);
        r.r[4] = TERRITORY_TZ_API_EXT; /* If not supported, never mind */
        if (_kernel_swi(Territory_ReadTimeZones, &r, &r) == NULL)
        {
            v = (dst == 0x8000) ? r.r[3] : r.r[2];
            t += v / 100; /* centiseconds -> seconds */
        }
    }

Adjust-click on Switcher icon opens system configuration

click_select
        LDR     R0,[R1,#b_window]
        CMP     R0,#iconbar_whandle
        BEQ     openswitcher
        BNE     click_common

click_adjust
        LDR     R0,[R1,#b_window]
        CMP     R0,#iconbar_whandle
        BEQ     goconfig

; it's not a click on the iconbar icon so try our windows
; for this we treat select and adjust click the same

click_common
        LDR     R14,h_powerdown         ; was it the power down dialogue
        TEQ     R0,R14
        BEQ     power_click

        LDR     R14,h_shutdown          ; click in restart dialogue?
        TEQ     R0,R14
        BEQ     restart

        LDR     R14,h_savedbox
        TEQ     R0,R14
        BEQ     dbox_click

        LDR     R14,h_switcher          ; click in task window?
        TEQ     R0,R14                  ; no => assume iconbar icon
        BEQ     switcher_click

        Pull    "PC"                    ; ignore it if none of these

Larger RAMdisc?

You can get the memory back if you have the DebugTools module, just enter the following command:

RemoveDA "RAM disc"

Run IIC at a decent speed

To do this on a RaspberryPi, go to ...mixed.RiscOS.Sources.HAL.BCM2836.s.IIC and change lines 54 and 55 from:

; IIC divider to give 100 kHz
IICDivider             * 2496

; IIC divider to give ~400 kHz
IICDivider             * 624

For the OMAP3 hardware (Beagle boards), you will want to look at the relevant HAL code. OMAP3 sets the speed around line 127, though I've not looked to see what values are required.
You don't need to modify OMAP4 (Panda) hardware, it already runs at 400kHz.
You should leave Iyonix and IOMD hardware running at 100kHz. If any machine is likely to interface with old (slow) hardware, it's the RiscPC... moreso given that there is no hardware IIC controller on either device, it's all done by directly bashing two lines on the IOMD (RiscPC) and whatever the I/O chip in the Iyonix is - about as technically advanced as the original Archimedes!

FullHD sucks if you are recycling a normal analogue monitor

But we can fix that. Of course we can. Go to ...mixed.RiscOS.Sources.Video.HWSupport.BCMVideo.Resources.RPIMon. This is the "default" built-in MDF.

You'll see a list of modes being defined. 1080P basic, then 720P basic. After those, insert your own mode. The Pi's GPU generates its own timings, so you set all of these to zero and basically just fill in the pixel rate and the screen dimensions. To work out the appropriate pixel rate for a given screen frequency, add 32 to the horizontal size, then multiply by the frequency that you want. It's a rough and ready way to do it, but it seems to get approximately correct values. The Pi does this by itself anyway, I just think it would be useful for RISC OS to be think it's using the same sort of frame rate to what is actually being used!

The calculation again:

 ( screen_width + 32 ) * desired_refresh_rate

 ( 1280 + 32 ) * 75 = 98400

Armed with this information, after the two HD definitions, add your own, like this, change the numbers as necessary:

# Mode: 1280x1024 at 75Hz
startmode
  mode_name:1280 x 1024
  x_res:1280
  y_res:1024
  pixel_rate:98400
  h_timings:0,0,0,1280,0,0
  v_timings:0,0,0,1024,0,0
  sync_pol:0
endmode

Now to tell RISC OS to actually use this mode. Open ...mixed.RiscOS.Sources.Video.HWSupport.BCMVideo.s.BCMVideo and around line 348, you will see a little block of data labelled startupmode. Amend this to match the mode that you have just defined in the MDF, like this:

startupmode
        DCD 1
        DCD 1280
        DCD 1024
        DCD 5
        DCD -1
        DCD -1

Optional: Make BootFX tidier

The default image is 1920×1080. It should be possible to change this, but when I tried it made the thing crashy. As it didn't seem terribly important (it just appears a bit squished), I never looked to see what was going on.
If you want to play, it is a JPEG file at ...bsd.RiscOS.Sources.Video.UserI.BootFX.Resources.Raspberry.UK.1920x1080.

Of more importance is the placement of the bars and text window are wrong. This, I'm afraid, you will have to determine by trial and error by building a softload version of the module, loading it, and calling the commands to get the bar and window to appear on-screen.

Around line 201 of ...bsd.RiscOS.Sources.Video.UserI.BootFX.c.bootfx, you will see this:

#if (defined UserIF_Raspberry)
#define BAR_X (1280)
#define BAR_Y (786)
static tclip_t text_window = { 28, 80, 125, 159, 94 };
#else

Here are the settings that look good on a 1280x1024 display:

#if (defined UserIF_Raspberry)
#define BAR_X (650)
#define BAR_Y (850)
static tclip_t text_window = { 28, 40, 110, 120, 76 };
#else

Bake in a better Next slot

At the end of ...castle.RiscOS.Sources.Desktop.Wimp.Options.s.!Default, you will see the line to tweak. I suggest the following:

        GBLA    DefaultNextSlot
DefaultNextSlot SETA 4096*1024

Speedier building

Then, when you're done, simply use !Builder to perform the Install ROM and Join ROM phases. On an original Pi with slow media, it takes about eight minutes to run the Install phase, and about fifteen seconds to Join the ROM.

The final touch

Once you've done that, reboot (shutdown properly, don't hit Ctrl-Break or press the reset button) and your options should be preserved.

Your comments:

Please note that while I check this page every so often, I am not able to control what users write; therefore I disclaim all liability for unpleasant and/or infringing and/or defamatory material. Undesired content will be removed as soon as it is noticed. By leaving a comment, you agree not to post material that is illegal or in bad taste, and you should be aware that the time and your IP address are both recorded, should it be necessary to find out who you are. Oh, and don't bother trying to inline HTML. I'm not that stupid! ☺ ADDING COMMENTS DOES NOT WORK IF READING TRANSLATED VERSIONS.
 
You can now follow comment additions with the comment RSS feed. This is distinct from the b.log RSS feed, so you can subscribe to one or both as you wish.

No comments yet...

Add a comment (v0.11) [help?] . . . try the comment feed!
		Your name
		Your email	(optional)
		Validation	Are you real? Please type 79695 backwards.
		Your comment