Re: [ECOS] Creating a drop in replacement for the pcmb package

[Ian Campbell <icampbell at arcom dot co dot uk>]

On Tue, 2001-10-02 at 21:50, Jonathan Larmour wrote:
> Ian Campbell wrote:
> > The other attached patch (memsize-fixes.patch - which I am posting more
> > for comment than inclusion since it may not be the correct approach) is
> > to allow the memory size to be hardcoded. The display attributes in the
> > CDL have FIXMEs because I am not entirely sure how to describe what they
> > are. I'm also not convinced by my choice of option names.
> 
> That's very good for a CDL newbie though! I think CYGNUM_HAL_MEMSIZE would
> be better as CYGPKG_HAL_I386_PCMB_MEMSIZE. 

I've attached a new version of the patch with this new name, and what I
hope are more correct descriptions. Patch also includes the RTC_PERIOD
change below (they were v. close in the source, which makes splitting
the two patches a pain..)

> 
> > I would like to be able to change the value of CYGNUM_HAL_RTC_PERIOD in
> > hal_i386_pcmb.cdl, however it is defined using a 'calculated' statement.
> > Is there any problem with making this into a 'default_value'?
> 
> Yeah, for now; although I'd be tempted just to move it down into the
> platform. I take it the merlin doesn't use an 8253 compatible PIT then?

As I understand it, the PIT is 8253 compatible, but the crystal is not
PC standard frequency. The 386EX has a pre-scale register which scales
the clock input for the PIT. The upshot is that PIT0 needs a
non-standard count to generate the 18.2Hz clock.

Cheers,
Ian.

-- 
Ian Campbell
Design Engineer

Arcom Control Systems Ltd,
Clifton Road,
Cambridge CB1 7EA
United Kingdom

Tel: +44 (0)1223 411200 ext. 3204
E-Mail: icampbell@arcom.co.uk
Web: http://www.arcomcontrols.com


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Index: packages/hal/i386/pcmb/current/ChangeLog
===================================================================
RCS file: /cvs/ecos/ecos/packages/hal/i386/pcmb/current/ChangeLog,v
retrieving revision 1.7
diff -u -r1.7 ChangeLog
--- packages/hal/i386/pcmb/current/ChangeLog	2001/10/05 15:31:49	1.7
+++ packages/hal/i386/pcmb/current/ChangeLog	2001/10/08 12:47:28
@@ -1,3 +1,12 @@
+2001-10-08  Ian Campbell  <icampbell@arcom.co.uk>
+
+	* cdl/hal_i386_pcmb.cdl: Add cdl_options for
+	CYGPKG_HAL_I386_PCMB_MEMSIZE to allow configuration of how memory
+	is detected. Change CYGNUM_HAL_RTC_PERIOD to use default_value
+	rather than calculated (so it can be overridden in the platform).
+	* src/pcmb_misc.c: Implement CYGPKG_HAL_I386_PCMB_MEMSIZE
+	configuration options.
+	
 2001-10-01  Ian Campbell  <icampbell@arcom.co.uk>
 
 	* include/pcmb_io.h: Include CYGBLD_HAL_PLATFORM_H rather than
Index: packages/hal//i386/pcmb/current/cdl/hal_i386_pcmb.cdl
===================================================================
RCS file: /cvs/ecos/ecos/packages/hal/i386/pcmb/current/cdl/hal_i386_pcmb.cdl,v
retrieving revision 1.3
diff -u -r1.3 hal_i386_pcmb.cdl
--- packages/hal/i386/pcmb/current/cdl/hal_i386_pcmb.cdl	2001/09/12 00:59:23	1.3
+++ packages/hal/i386/pcmb/current/cdl/hal_i386_pcmb.cdl	2001/10/08 12:36:54
@@ -83,11 +83,36 @@
         cdl_option CYGNUM_HAL_RTC_PERIOD {
             display       "Real-time clock period"
             flavor        data
-           calculated     11932
+	    default_value 11932
         }
     }
 
-    
+    cdl_component CYGPKG_HAL_I386_PCMB_MEMSIZE {
+	display       "How to discover the size of available RAM."
+	flavor        data
+	legal_values  {"BIOS" "HARDCODE"}
+	default_value {"BIOS"}
+	description   "It is possible for the HAL to discover the 
+	               size of RAM In several ways. Currently this
+                       can be done by querying the BIOS or by 
+                       hardcoding the values into the executable."
+
+	cdl_option CYGPKG_HAL_I386_PCMB_MEMSIZE_BASE {
+	    display       "Amount of Base RAM available."
+	    flavor        data
+	    default_value 0x000F0000
+	    active_if     { CYGPKG_HAL_I386_PCMB_MEMSIZE == "HARDCODE" }
+	}
+
+	cdl_option CYGPKG_HAL_I386_PCMB_MEMSIZE_EXTENDED {
+	    display       "Amount of Extended RAM available."
+	    flavor        data
+	    default_value 0x00100000
+	    active_if     { CYGPKG_HAL_I386_PCMB_MEMSIZE == "HARDCODE" }
+	}
+
+    }
+
     cdl_interface CYGINT_HAL_I386_PCMB_SCREEN_SUPPORT {
 	display       "Enable PC screen support"
 	compile       pcmb_screen.c
Index: packages/hal//i386/pcmb/current/src/pcmb_misc.c
===================================================================
RCS file: /cvs/ecos/ecos/packages/hal/i386/pcmb/current/src/pcmb_misc.c,v
retrieving revision 1.3
diff -u -r1.3 pcmb_misc.c
--- packages/hal/i386/pcmb/current/src/pcmb_misc.c	2001/09/12 00:59:23	1.3
+++ packages/hal/i386/pcmb/current/src/pcmb_misc.c	2001/10/08 12:36:54
@@ -70,6 +70,12 @@
 
 void hal_pcmb_init(void)
 {
+#ifdef CYG_HAL_MEMSIZE_HARDCODE
+    cyg_hal_pcmb_memsize_base = CYGPKG_HAL_I386_PCMB_MEMSIZE_BASE;
+    cyg_hal_pcmb_memsize_extended = CYGPKG_HAL_I386_PCMB_MEMSIZE_EXTENDED;
+#endif
+
+#ifdef CYG_HAL_MEMSIZE_BIOS
     cyg_uint8 lo,hi;
     
     HAL_READ_CMOS( 0x15, lo );
@@ -89,7 +95,7 @@
 #endif
 
     cyg_hal_pcmb_memsize_extended = ((hi<<8)+lo)*1024;
-
+#endif
 }
 
 /*------------------------------------------------------------------------*/