Modify userspace .org and RAMSTART expectations

Instead of expecting a `USER_CODE` symbol to be set, we expect `.org` to be
set in all userspace glue code. This gives us more flexibility with regards to
how we manage that.

Moreover, instead of making `USER_RAMSTART` mandatory, we make it default to
the end of the binary, which is adequate in a majority of cases.

Will be useful for my upcoming mega-commit... :)

apps/README.md

@@ -10,8 +10,16 @@ you will typically not want to do that.
 
 ## Userspace convention
 
-We execute a userspace application by calling the address it's loaded into. This
-means: a userspace application is expected to return.
+We execute a userspace application by calling the address it's loaded into.
+
+This means that userspace applications must be assembled with a proper `.org`,
+otherwise labels in its code will be wrong.
+
+The `.org`, it is not specified by glue code of the apps themselves. It is
+expected to be set either in the `user.h` file to through `zasm` 3rd argument.
+
+That a userspace is called also means that an application, when finished
+running, is expected to return with a regular `ret` and a clean stack.
 
 Whatever calls the userspace app (usually, it will be the shell), should set
 HL to a pointer to unparsed arguments in string form, null terminated.
@@ -25,3 +33,8 @@ because otherwise, it will break the kernel.
 
 Apps in Collapse OS are design to be ROM-compatible, that is, they don't write
 to addresses that are part of the code's address space.
+
+By default, apps set their RAM to begin at the end of the binary because in
+most cases, these apps will be ran from RAM. If they're ran from ROM, make sure
+to set `USER_RAMSTART` properly in your `user.h` to ensure that the RAM is
+placed properly.

apps/at28w/glue.asm

@@ -16,9 +16,9 @@
 
 .inc "user.h"
 .inc "err.h"
-.org	USER_CODE
 .equ	AT28W_RAMSTART	USER_RAMSTART
 
 jp	at28wMain
 
 .inc "at28w/main.asm"
+USER_RAMSTART:

apps/basic/glue.asm

@@ -7,7 +7,6 @@
 .inc "user.h"
 
 .inc "err.h"
-.org	USER_CODE
 
 	jp	basStart
 
@@ -16,3 +15,4 @@
 .inc "lib/parse.asm"
 .equ	BAS_RAMSTART	USER_RAMSTART
 .inc "basic/main.asm"
+USER_RAMSTART:

apps/ed/glue.asm

@@ -26,8 +26,6 @@
 ; ******
 
 .inc "err.h"
-.org	USER_CODE
-
 	jp	edMain
 
 .inc "core.asm"
@@ -41,3 +39,4 @@
 .inc "ed/cmd.asm"
 .equ	ED_RAMSTART	CMD_RAMEND
 .inc "ed/main.asm"
+USER_RAMSTART:

apps/memt/glue.asm

@@ -13,8 +13,7 @@
 ; *** Includes ***
 
 .inc "user.h"
-.org	USER_CODE
-
 jp	memtMain
 
 .inc "memt/main.asm"
+USER_RAMSTART:

apps/sdct/glue.asm

@@ -19,9 +19,9 @@
 ; *** Includes ***
 
 .inc "user.h"
-.org	USER_CODE
 .equ	SDCT_RAMSTART	USER_RAMSTART
 
 jp	sdctMain
 
 .inc "sdct/main.asm"
+USER_RAMSTART:

apps/zasm/glue.asm

@@ -64,8 +64,6 @@
 
 .inc "err.h"
 .inc "ascii.h"
-.org	USER_CODE
-
 jp	zasmMain
 
 .inc "core.asm"
@@ -87,3 +85,4 @@ jp	zasmMain
 .inc "zasm/symbol.asm"
 .equ	ZASM_RAMSTART	SYM_RAMEND
 .inc "zasm/main.asm"
+USER_RAMSTART:

recipes/rc2014/zasm/user.h

@@ -1,6 +1,5 @@
-.equ    USER_CODE       0x8700
-.equ    USER_RAMSTART   USER_CODE+0x1900
-.equ    FS_HANDLE_SIZE  6
+.org    0x8700
+.equ    FS_HANDLE_SIZE  8
 .equ    BLOCKDEV_SIZE   8
 
 ; *** JUMP TABLE ***

recipes/sms/romasm/Makefile

@@ -5,13 +5,13 @@ APPS = ../../../apps
 .PHONY: all clean
 all: os.sms
 
+# -o value synced with offset in glue.asm
 ed.bin: $(APPS)/ed/glue.asm
-	echo ".equ USER_CODE ED_CODE" | cat user-tmpl.h - > user.h
-	$(ZASM) $(KERNEL) $(APPS) user.h < $< > $@
+	$(ZASM) -o 19 $(KERNEL) $(APPS) user.h < $< > $@
 
+# -o value synced with offset in glue.asm
 zasm.bin: $(APPS)/zasm/glue.asm
-	echo ".equ USER_CODE ZASM_CODE" | cat user-tmpl.h - > user.h
-	$(ZASM) $(KERNEL) $(APPS) user.h < $< > $@
+	$(ZASM) -o 1d $(KERNEL) $(APPS) user.h < $< > $@
 
 os.sms: glue.asm ed.bin zasm.bin
 	$(ZASM) $(KERNEL) ed.bin zasm.bin < $< > $@

recipes/sms/romasm/user.h

@@ -1,8 +1,5 @@
-; USER_CODE is filled in on-the-fly with either ED_CODE or ZASM_CODE
-.equ    ED_CODE         0x1900
-.equ    ZASM_CODE       0x1d00
 .equ    USER_RAMSTART   0xc200
-.equ    FS_HANDLE_SIZE  6
+.equ    FS_HANDLE_SIZE  8
 .equ    BLOCKDEV_SIZE   8
 ; Make ed fit in SMS's memory
 .equ    ED_BUF_MAXLINES 0x100

tools/emul/cfsin/hello.asm

@@ -1,6 +1,4 @@
 .inc "user.h"
-.org	USER_CODE
-
 	ld	hl, sAwesome
 	call	printstr
 	xor	a		; success

tools/emul/shell/user.h

@@ -1,5 +1,4 @@
-.equ    USER_CODE       0x4200
-.equ    USER_RAMSTART   USER_CODE+0x1800
+.org    0x4200              ; in sync with USERCODE in shell/shell_.asm
 .equ    FS_HANDLE_SIZE  8
 .equ    BLOCKDEV_SIZE   8
 

tools/emul/zasm/user.h

@@ -1,4 +1,4 @@
-.equ    USER_CODE       0x4800
+.org    0x4800          ; in sync with USER_CODE in glue.asm
 .equ    USER_RAMSTART   0x6000
 .equ    FS_HANDLE_SIZE  8
 .equ    BLOCKDEV_SIZE   8