From: Alan Cox <alan@linux.intel.com>
Date: Sat, 5 Nov 2016 22:43:54 +0000 (+0000)
Subject: coco2cart: updates and add missed file
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=af856af0445f4861ab81196c8a955e589555d588;p=FUZIX.git

coco2cart: updates and add missed file
---

diff --git a/Kernel/platform-coco2cart/Makefile b/Kernel/platform-coco2cart/Makefile
index 361874be..45403835 100644
--- a/Kernel/platform-coco2cart/Makefile
+++ b/Kernel/platform-coco2cart/Makefile
@@ -51,7 +51,7 @@ $(AOBJS): %$(BINEXT): %.s
 clean:
 	rm -f *.o *~
 
-image: bootfuz.bin
+image:
 	$(CROSS_LD) -o ../fuzix.bin --map=../fuzix.map --script=fuzix.link \
 	crt0.o bootstrap.o commonmem.o coco2.o discard.o ../simple.o \
 	../start.o ../version.o ../lowlevel-6809.o \
@@ -64,6 +64,4 @@ image: bootfuz.bin
 	../font8x8.o
 	../tools/decb-image <../fuzix.bin fuzix.img
 
-bootfuz.bin: bootloader.s
-	lwasm -r -b -obootfuz.bin bootloader.s
 
diff --git a/Kernel/platform-coco2cart/README b/Kernel/platform-coco2cart/README
index eb80b6f4..fb093f26 100644
--- a/Kernel/platform-coco2cart/README
+++ b/Kernel/platform-coco2cart/README
@@ -1,23 +1,37 @@
 COCO2
 =====
 
+(Work in progress)
+
 COCO or Dragon 64 with an IDE port, cartridge and 64K of RAM
 
 Supported hardware:
-	IDE (Glenside or compatible)
+	IDE (Cloud9 or compatible set at FF40) with either built in
+		cartridge RAM or separate cartridge
 
 Memory Map
 ==========
+
+User View
+=========
 0000-00FF	Interrupt stack
 0100-01FF	Vectors (then wasted - could hide libc.o in there ?)
 0200-19FF	Display
 1A00-1BFF	udata/stack
-1C00-7FFF	Code/Data for common plus some kernel
+1C00-7FFF	Common, data and some kernel code
 8000-FEFF	User space
 FF00-FFFF	I/O etc
 
-Cartridge
+Kernel Mode View
+================
+0000-00FF	Interrupt stack
+0100-01FF	Vectors
+0200-19FF	Display
+1A00-1BFF	udata/stack
+1C00-7FFF	Common, data and some kernel code
+8000-BFFF	ROM
 C000-FEFF	Kernel
+FF00-FFFF	I/O etc
 
 
 Emulating in XRoar
@@ -28,39 +42,24 @@ Needs the IDE patches
 TODO
 ====
 
-Loader code
-Set the display up correctly
+Test it
+Make the boot loader robust (timeout handling)
+Add magic numbers to check we loaded the right thing!
 Support for a real time clock and clock locking
 Review irq disabling. We shouldn't need much of this at all as we don't have
 floppy hell to contend with, but the switchin/switchout logic needs to be
 reviewed for interrupt safety and the IRQs re-enabled during swap in and
 out. We should also be totally clean now on FIR blocking, so audio might
-actually be doable!
+actually be doable if not doing drivewire.
 
 MPI switching
 
-Could we do a cartridge version
-- Re-order so common is in low memory
-- Support map_kernel/map_process flipping
-- Add asm helpers for user mode copying (trivial - and since we never copy
-  into kernel ROM we can optimise them a lot - one map switch only)
 - Fix IDE to support the map flip on transfers (needs little asm code
   adding)
-- How to do discard, can we just take the hit or do we need to copy the
-  entire cartridge into high RAM, run in high RAM with discard at say
-  0xA000 and then in platform_discard switch on map_kernel cartridge
-  selection so we can let userspace blow away the upper 32K of the RAM
-  mapping.
-
-16K Cartridge version would give us space for
-- Proper video (costs us about 8K)
-- Nice loader (just 'EXEC $C000' and go) < 1K
-- Probably all of sound/joysticks/printer/floppy and a few more buffers
-- Full size user memory bank (so can run full v7 shell) 4K
-
-
-Write a loader into the cartridge start so it bootstraps off disk and runs
-nicely
+- reclaim discard space by packing bss, then buffers then discard
 
-6847T1 lower case ?
+We have about 2K left to try and jam those bits in which might just about be
+enough to add support for very minimal MBR parsing and offsets. That would
+be a big improvement and make the current loading of the kernel image from
+blocks 1-51 of the disk sensible. If not we need to move it.
 
diff --git a/Kernel/platform-coco2cart/kernel.def b/Kernel/platform-coco2cart/kernel.def
new file mode 100644
index 00000000..45787954
--- /dev/null
+++ b/Kernel/platform-coco2cart/kernel.def
@@ -0,0 +1,26 @@
+; UZI mnemonics for memory addresses etc
+
+U_DATA                      equ 0x1A00       ; (this is struct u_data from kernel.h)
+U_DATA__TOTALSIZE           equ 0x0200        ; 256+256
+
+VIDEO_BASE		    equ 0x0200	     ; 512 bytes for the display
+VIDEO_END		    equ 0x1A00
+
+IDEDATA			    equ 0xFF50
+IDEDATA_L		    equ 0xFF58
+
+PROGBASE                    equ 0x8000       ; programs and data start here
+
+; Have these defined so that lowlevel-6809.s can be used as-is
+SAM_USER macro
+	endm
+
+SAM_KERNEL macro
+	endm
+
+SAM_SAVE macro
+	endm
+
+SAM_RESTORE macro
+	endm
+