Merge https://github.com/kervinck/gigatron-rom

Apps/CardTest/CardBoot.gcl

@@ -121,7 +121,7 @@ gcl0x
 |                       RAM page 2                                      |
 +-----------------------------------------------------------------------}
 
-\romType, \romTypeValue_DEVROM- {Version check >= DEVROM}
+\romType, \romTypeValue_ROMv5-  {Version check >= ROMv5}
 [if<0 do _frameCount _vPCH: loop]
 
 $500 Address=                   {512 bytes memory for one sector}

Apps/Loader/SYS_Loader_v4.py

@@ -70,24 +70,24 @@
 ld([Y,X]);                      C('Valid command')#24 Length byte
 st([Y,Xpp]);                    C('Just X++')#25
 anda(63)                        #26 Bit 6:7 are garbage
-st([sysArgs+4])                 #27 Copy count
-adda([Y,X])                     #28 One past last address
-adda(1)                         #29 $ff->0, $00->1
-anda(0xfe)                      #30 Zero if writing top 2 bytes in page
-st([vTmp])                      #31
+st([sysArgs+4])                 #27 Copy count 0..60
+adda([Y,X])                     #28 One location past (+1) the last byte of fragment
+adda(1)                         #29 254+1 = $ff becomes 0, 255+1 = $00 becomes 1
+anda(0xfe)                      #30 Will be zero iff writing in top 2 bytes of page
+st([vTmp])                      #31 Remember as first condition
 ld([Y,X])                       #32 Low copy address
 st([Y,Xpp]);                    C('Just X++')#33
 st([sysArgs+5])                 #34
 ld([Y,X])                       #35 High copy address
 st([Y,Xpp]);                    C('Just X++')#36
 st([sysArgs+6])                 #37
-suba(1)                         #38 Check if writing to sound channel page
+suba(1)                         #38 Check if writing into sound channel page (1..4)
 anda(0xfc)                      #39
-ora([vTmp])                     #40
+ora([vTmp])                     #40 Combine second condition with first
 bne(pc()+3)                     #41
 bra(pc()+3)                     #42
-ld(0xfc);                       C('Unsafe')#43
-ld(0xff);                       C('Safe')#43(!)
+ld(0xfc);                       C('Unsafe')#43  Clear low channelMask bits so it becomes safe
+ld(0xff);                       C('Safe')#43(!) No change to channelMask because already safe
 anda([channelMask])             #44
 st([channelMask])               #45
 ld([sysArgs+4])                 #46

Apps/Loader/SYS_Loader_vX.py

@@ -0,0 +1,161 @@
+
+#-----------------------------------------------------------------------
+#
+#       Loader-specific SYS extensions
+#
+#-----------------------------------------------------------------------
+
+from asm import *
+
+# Peek into the ROM's symbol table
+videoY = symbol('videoY')
+sysArgs = symbol('sysArgs0')
+vPC = symbol('vPC')
+vLR = symbol('vLR')
+vTmp = symbol('vTmp')
+channelMask = symbol('channelMask_v4')
+
+#-----------------------------------------------------------------------
+# Extension SYS_LoaderNextByteIn_32
+#-----------------------------------------------------------------------
+
+# sysArgs[0:1] Current address
+# sysArgs[2]   Checksum
+# sysArgs[3]   Wait value (videoY)
+
+label('SYS_LoaderNextByteIn_32')
+ld([videoY])                    #15
+xora([sysArgs+3])               #16
+bne('.sysNbi#19')               #17
+ld([sysArgs+0],X)               #18
+ld([sysArgs+1],Y)               #19
+ld(IN)                          #20
+st([Y,X])                       #21
+adda([sysArgs+2])               #22
+st([sysArgs+2])                 #23
+ld([sysArgs+0])                 #24
+adda(1)                         #25
+st([sysArgs+0])                 #26
+ld(hi('REENTER'),Y)             #27
+jmp(Y,'REENTER')                #28
+ld(-32/2)                       #29
+# Restart the instruction in the next timeslice
+label('.sysNbi#19')
+ld([vPC])                       #19
+suba(2)                         #20
+st([vPC])                       #21
+ld(hi('NEXTY'),Y)               #22
+jmp(Y,'NEXTY')                  #23
+ld(-26/2)                       #24
+
+#-----------------------------------------------------------------------
+# Extension SYS_LoaderProcessInput_64
+#-----------------------------------------------------------------------
+
+# sysArgs[0:1] Source address
+# sysArgs[2]   Checksum
+# sysArgs[4]   Copy count
+# sysArgs[5:6] Destination address
+
+label('SYS_LoaderProcessInput_64')
+ld([sysArgs+1],Y)               #15
+ld([sysArgs+2])                 #16
+bne('.sysPi#19')                #17
+ld([sysArgs+0])                 #18
+suba(65,X)                      #19 Point at first byte of buffer
+ld([Y,X])                       #20 Command byte
+st([Y,Xpp]);                    C('Just X++')#21
+xora(ord('L'))                  #22 This loader lumps everything under 'L'
+bne('.sysPi#25')                #23
+ld([Y,X]);                      C('Valid command')#24 Length byte
+st([Y,Xpp]);                    C('Just X++')#25
+anda(63)                        #26 Bit 6:7 are garbage
+st([sysArgs+4])                 #27 Copy count 0..60
+adda([Y,X])                     #28 One location past (+1) the last byte of fragment
+adda(1)                         #29 254+1 = $ff becomes 0, 255+1 = $00 becomes 1
+anda(0xfe)                      #30 Will be zero only when writing in top 2 bytes of page
+st([vTmp])                      #31 Remember as first condition
+ld([Y,X])                       #32 Low copy address
+st([Y,Xpp]);                    C('Just X++')#33
+st([sysArgs+5])                 #34
+ld([Y,X])                       #35 High copy address
+st([Y,Xpp]);                    C('Just X++')#36
+st([sysArgs+6])                 #37
+suba(1)                         #38 Check if writing into sound channel page (1..4)
+anda(0xfc)                      #39
+ora([vTmp])                     #40 Combine second condition with first
+st([vTmp])                      #41 Zero when overwriting one of oscL[1..4] or oscH[1..4]
+ld([sysArgs+4])                 #42 Check copy count
+bne('.sysPi#45')                #43
+# Execute code (don't care about checksum anymore)
+ld([sysArgs+5]);                C('Execute')#44 Low run address
+st([vLR])                       #45 https://forum.gigatron.io/viewtopic.php?p=29#p29
+suba(2)                         #46
+st([vPC])                       #47
+ld([sysArgs+6])                 #48 High run address
+st([vPC+1])                     #49
+st([vLR+1])                     #50
+ld(hi('REENTER'),Y)             #51
+jmp(Y,'REENTER')                #52
+ld(-56/2)                       #53
+# Invalid checksum
+label('.sysPi#19')
+wait(25-19);                    C('Invalid checksum')#19 Reset checksum
+# Unknown command
+label('.sysPi#25')
+ld(ord('g'));                   C('Unknown command')#25 Reset checksum
+st([sysArgs+2])                 #26
+ld(hi('REENTER'),Y)             #27
+jmp(Y,'REENTER')                #28
+ld(-32/2)                       #29
+# Loading data
+label('.sysPi#45')
+ld([vTmp]);                     C('Loading data')#45
+bne(pc()+3)                     #46
+bra(pc()+3)                     #47
+ld(0xfc);                       C('Unsafe')#48  Clear low channelMask bits so it becomes safe
+ld(0xff);                       C('Safe')#48(!) No change to channelMask because already safe
+anda([channelMask])             #49
+st([channelMask])               #50
+ld([sysArgs+0])                 #51 Continue checksum
+suba(1,X)                       #52 Point at last byte
+ld([Y,X])                       #53
+st([sysArgs+2])                 #54
+ld(hi('REENTER'),Y)             #55
+jmp(Y,'REENTER')                #56
+ld(-60/2)                       #57
+
+#-----------------------------------------------------------------------
+# Extension SYS_LoaderPayloadCopy_34
+#-----------------------------------------------------------------------
+
+# sysArgs[0:1] Source address
+# sysArgs[4]   Copy count
+# sysArgs[5:6] Destination address
+
+label('SYS_LoaderPayloadCopy_34')
+ld([sysArgs+4])                 #15 Copy count
+beq('.sysCc#18')                #16
+suba(1)                         #17
+st([sysArgs+4])                 #18
+ld([sysArgs+0],X)               #19 Current pointer
+ld([sysArgs+1],Y)               #20
+ld([Y,X])                       #21
+ld([sysArgs+5],X)               #22 Target pointer
+ld([sysArgs+6],Y)               #23
+st([Y,X])                       #24
+ld([sysArgs+5])                 #25 Increment target
+adda(1)                         #26
+st([sysArgs+5])                 #27
+bra('.sysCc#30')                #28
+label('.sysCc#18')
+ld(hi('REENTER'),Y)             #18,29
+wait(30-19)                     #19
+label('.sysCc#30')
+jmp(Y,'REENTER')                #30
+ld(-34/2)                       #31
+
+#-----------------------------------------------------------------------
+#
+#-----------------------------------------------------------------------
+

Core/ROMv5a.asm.py

@@ -159,7 +159,7 @@
 
 from asm import *
 import gcl0x as gcl
-import font_vX as font
+import font_v4 as font
 
 enableListing()
 #-----------------------------------------------------------------------

Core/dev.asm.py

@@ -159,7 +159,7 @@
 
 from asm import *
 import gcl0x as gcl
-import font_vX as font
+import font_v4 as font
 
 enableListing()
 #-----------------------------------------------------------------------

Makefile

@@ -40,7 +40,7 @@ dev.rom: Core/* Apps/*/* Makefile interface.json
 		zippedRacerHorizon=Apps/Racer/Horizon-256x16.rgb\
 		Racer=Apps/Racer/Racer_v2.gcl\
 		Mandelbrot=Apps/Mandelbrot/Mandelbrot_v1.gcl\
-		SYS_Loader_v4.py\
+		SYS_Loader_vX.py\
 		Pictures=Apps/Pictures/Pictures_v3.gcl\
 		Loader=Apps/Loader/Loader_v4.gcl\
 		Credits=Apps/Credits/Credits_v3.gcl\