Implement relocation tables in KEXC binaries

.build.yml

@@ -1,17 +1,23 @@
 image: archlinux
 packages:
-  - mono
   - make
-  - sass
   - mktiupgrade
   - genkfs
   - mkrom
   - patchrom
 sources:
   - https://github.com/KnightOS/kernel
+  - https://github.com/KnightOS/scas
 environment:
   project: kernel
 tasks:
+  - scas: |
+      cd scas
+      mkdir build
+      cd build
+      cmake ..
+      make
+      sudo make install
   - ti73: |
       cd ${project}
       make TI73

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2014 The KnightOS Group
+Copyright (c) 2014-2020 The KnightOS Group
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

Makefile

@@ -1,11 +1,14 @@
 # Makefile for KnightOS kernel
-AS=sass
-ASFLAGS=--encoding "Windows-1252"
+AS=scas
+ASFLAGS=-v
+#ASFLAGS=--encoding "Windows-1252"
 .DEFAULT_GOAL=TI84pSE
 PLATFORM:=TI84pSE
-TAG:=$(shell git describe --abbrev=0)
+TAG:=$(shell git describe --abbrev=0 --dirty=+)
 OUTDIR=bin/
 
+KERNEL_VERSION = -DKERNEL_VERSION=$(TAG)
+
 # Platforms:
 # Variables (all in hex):
 #	PRIVILEGED: The address of the privileged page
@@ -65,7 +68,7 @@ TI84pCSE: BOOT := 3FC000
 TI84pCSE: LENGTH := 0x400000
 TI84pCSE: kernel $(OUTDIR)
 
-DEFINES=--define $(PLATFORM)
+DEFINES=--define $(PLATFORM) $(KERNEL_VERSION)
 BINDIR=$(OUTDIR)$(PLATFORM)/
 INCLUDE=include/;$(BINDIR)
 
@@ -109,28 +112,18 @@ baserom:
 	mkdir -p $(BINDIR)
 	mkrom $(BINDIR)kernel.rom $(LENGTH) /dev/null:0x00
 
-$(OUTDIR)$(PLATFORM)/00.bin: src/00/*.asm include/constants.asm src/00/jumptable.config
-	@mkdir -p $(BINDIR)
-	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/00/" --symbols $(BINDIR)00.sym --listing $(BINDIR)00.list src/00/base.asm $(BINDIR)00.bin
-	patchrom src/00/jumptable.config $(BINDIR)kernel.rom 00 < $(BINDIR)00.sym > $(BINDIR)00.inc
-
-$(OUTDIR)$(PLATFORM)/01.bin: $(OUTDIR)$(PLATFORM)/00.bin src/01/*.asm include/constants.asm src/01/jumptable.config
+$(OUTDIR)$(PLATFORM)/%.bin: src/%/*.asm include/constants.asm src/%/jumptable.config
 	@mkdir -p $(BINDIR)
-	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/01/" --symbols $(BINDIR)01.sym --listing $(BINDIR)01.list src/01/base.asm $(BINDIR)01.bin
-	patchrom src/01/jumptable.config $(BINDIR)kernel.rom 01 < $(BINDIR)01.sym > $(BINDIR)01.inc
-
-$(OUTDIR)$(PLATFORM)/02.bin: $(OUTDIR)$(PLATFORM)/00.bin src/02/*.asm include/constants.asm src/02/jumptable.config
-	@mkdir -p $(BINDIR)
-	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/02/" --symbols $(BINDIR)02.sym --listing $(BINDIR)02.list src/02/base.asm $(BINDIR)02.bin
-	patchrom src/02/jumptable.config $(BINDIR)kernel.rom 02 < $(BINDIR)02.sym > $(BINDIR)02.inc
+	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/$*/" --symbols $(BINDIR)$*.sym --listing $(BINDIR)$*.list src/$*/base.asm -o $(BINDIR)$*.bin
+	patchrom src/$*/jumptable.config $(BINDIR)kernel.rom $* < $(BINDIR)$*.sym > $(BINDIR)$*.inc
 
 $(OUTDIR)$(PLATFORM)/privileged.bin: src/privileged/*.asm include/constants.asm $(OUTDIR)$(PLATFORM)/00.bin
 	@mkdir -p $(BINDIR)
-	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/privileged/" --listing $(BINDIR)priviledged.list src/privileged/base.asm $(BINDIR)privileged.bin
+	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/privileged/" --listing $(BINDIR)priviledged.list src/privileged/base.asm -o $(BINDIR)privileged.bin
 
 $(OUTDIR)$(PLATFORM)/boot.bin: src/boot/*.asm include/constants.asm
 	@mkdir -p $(BINDIR)
-	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/boot/" --listing $(BINDIR)boot.list src/boot/base.asm $(BINDIR)boot.bin
+	$(AS) $(ASFLAGS) $(DEFINES) --include "$(INCLUDE);src/boot/" --listing $(BINDIR)boot.list src/boot/base.asm -o $(BINDIR)boot.bin
 
 clean:
 	rm -rf $(OUTDIR)

doc/kexc

@@ -35,15 +35,16 @@ good idea.
 
 The following headers are defined in kernel.inc:
 
-    Name                Description
+    Name                  Description
 
-    KEXC_HEADER_END     The end of the header list. Value may be omitted.
-    KEXC_ENTRY_POINT    Pointer to executable entry point.
-    KEXC_STACK_SIZE     Bytes of stack required, divided by two.
-    KEXC_KERNEL_VER     Minimum kernel version supported. Major, minor.
-    KEXC_THREAD_FLAGS   Thread flags. Only the upper 8 bits are considered.
-    KEXC_NAME           Pointer to program name.
-    KEXC_DESCRIPTION    Pointer to program description.
+    KEXC_HEADER_END       The end of the header list. Value may be omitted.
+    KEXC_ENTRY_POINT      Pointer to executable entry point.
+    KEXC_STACK_SIZE       Bytes of stack required, divided by two.
+    KEXC_KERNEL_VER       Minimum kernel version supported. Major, minor.
+    KEXC_THREAD_FLAGS     Thread flags. Only the upper 8 bits are considered.
+    KEXC_NAME             Pointer to program name.
+    KEXC_DESCRIPTION      Pointer to program description.
+    KEXC_RELOCATION_TABLE Pointer to the relocation table.
 
 Header keys are numbered from 0x00-0xFF, inclusive. The 0x00-0x7F range is
 reserved for kernel use, and 0x80-0xFF is available for arbitrary use.
@@ -52,3 +53,9 @@ reserved for kernel use, and 0x80-0xFF is available for arbitrary use.
 
 When used to describe an executable program, the only required header is
 KEXC_ENTRY_POINT (and of course KEXC_HEADER_END).
+
+                               Relocation Table
+
+The relocation table consists of any number of program-relative addresses
+terminated by a null word. Those addresses should themselves contain
+program-relative pointers to relocate.

include/defines.inc

@@ -50,6 +50,7 @@ KEXC_KERNEL_VER         .equ 0x03
 KEXC_THREAD_FLAGS       .equ 0x04
 KEXC_NAME               .equ 0x05
 KEXC_DESCRIPTION        .equ 0x06
+KEXC_RELOCATION_TABLE   .equ 0x07
 
 ; Thread flags
 THREAD_NON_SUSPENDABLE  .equ 2

src/00/header.asm

@@ -44,5 +44,4 @@ rlcall:
 ; 0x0056
 .db 0xFF, 0xA5, 0xFF
 .fill 0x64-$
-.exec git describe --dirty=+ ; Version string
-.db 0
+.asciiz "KERNEL_VERSION"

src/00/locks.asm

@@ -90,7 +90,7 @@ hasUSBLock:
     push hl
     push af
         call getCurrentThreadId
-        ld hl, hwLockUsb
+        ld hl, hwLockUSB
         cp (hl)
     pop hl
     ld a, h

src/00/random.asm

@@ -47,7 +47,7 @@ getRandom:
         add hl, hl \ rl c \ rl b
         ld (random_seed+6), bc
         sbc a, a
-        and %11000101
+        and 0b11000101
         xor l
         ld l, a
         ld (random_seed+4), hl

src/00/thread.asm

@@ -390,7 +390,7 @@ launchProgram:
         ; Check magic number
         ld a, 'K'
         cp (ix)
-        jr nz, .magic_error
+        jp nz, .magic_error
         ld a, 'E'
         cp (ix + 1)
         jr nz, .magic_error
@@ -426,12 +426,18 @@ launchProgram:
 .unknown_ver:
 ; no minimum version is specified by the executable
 .no_minimum_ver:
+; Check for a relocation table
+        ld b, KEXC_RELOCATION_TABLE
+        push ix \ call _getThreadHeader \ pop ix
+        call z, .relocate
+
         ; Grab header info
         ld b, KEXC_ENTRY_POINT
         push ix \ call _getThreadHeader \ pop ix
         jr nz, .no_entry_point
         push hl
-            ld b, KEXC_STACK_SIZE
+            ; b still has KEXC_ENTRY_POINT, and KEXC_STACK_SIZE is 1 higher
+            inc b
             push ix \ call _getThreadHeader \ pop ix
             ld c, l ; TODO: Error out if H is nonzero?
             jr z, _
@@ -459,14 +465,14 @@ _:  ld a, b
     pop bc
     cp a
     ret
-.kernel_too_low:
-    ld a, errKernelMismatch
+.magic_error:
+    ld a, errNoMagic
     jr .error
 .no_entry_point:
     ld a, errNoEntryPoint
     jr .error
-.magic_error:
-    ld a, errNoMagic
+.kernel_too_low:
+    ld a, errKernelMismatch
     jr .error
 .error_pop2:
     inc sp \ inc sp
@@ -484,6 +490,42 @@ _:  or 1
     ld a, b
     pop bc
     ret
+; thrashes de, bc, and hl
+.relocate:
+; ix = executable address
+; hl = program-relative relocation table address
+    push ix \ pop de
+    add hl, de
+; hl = absolute address of relocation table
+.relocation_loop:
+    ld e, (hl)
+    inc hl
+    ld d, (hl)
+    ; de = first entry in relocation table
+    dec hl
+    ; hl: preserved
+    ld bc, 0
+    call cpBCDE
+    ret z
+    ; de contains the program-relative address of a program-relative pointer to relocate
+    ; need to execute, in effect, `add (ix + de), ix`
+    push ix
+        add ix, de
+        push ix \ pop de
+    pop ix
+    ; de = absolute address of pointer to relocate
+
+    ; add (de), ix
+    push ix \ pop bc
+    ld a, (de)
+    add a, c
+    ld (de), a
+    inc de
+    ld a, (de)
+    add a, b
+    ld (de), a
+    inc hl \ inc hl
+    jr .relocation_loop
 
 ;; exitThread [Threading]
 ;;  Immediately terminates the running thread.

src/02/crypto.asm

@@ -44,7 +44,7 @@ sha1Init:
 .defaultMemblock:
 
 ; Holds the completed hash.
-sha1_hash .equ $ - .defaultMemblock
+.equ sha1_hash, $ - .defaultMemblock
     .db 0x67,0x45,0x23,0x01
     .db 0xEF,0xCD,0xAB,0x89
     .db 0x98,0xBA,0xDC,0xFE
@@ -107,13 +107,13 @@ sha1Pad_noPush:
     ; append the bit '1' to the message
     ; append 0 <= k < 512 bits '0', so that the resulting message length (in bits)
     ;    is congruent to 448 = -64 (mod 512)
-    ld a, $80
+    ld a, 0x80
 .zero:
     call sha1AddByte_noLength
     ld a, (ix + sha1_block_front_ptr)
     add a, 56
     cp (ix + sha1_block_ptr)
-    ld a, $00
+    ld a, 0x00
     jr nz, .zero
     ; append length of message (before padding), in bits, as 64-bit big-endian integer
     push ix \ pop hl
@@ -223,10 +223,10 @@ sha1ProcessBlock:
         dec hl
         ld (ix + sha1_block_ptr), l
         ld (ix + sha1_block_ptr + 1), h
-        ld hl, sha1Operation_mux \ call sha1Do20Rounds \ .db $5A,$82,$79,$99
-        ld hl, sha1Operation_xor \ call sha1Do20Rounds \ .db $6E,$D9,$EB,$A1
-        ld hl, sha1Operation_maj \ call sha1Do20Rounds \ .db $8F,$1B,$BC,$DC
-        ld hl, sha1Operation_xor \ call sha1Do20Rounds \ .db $CA,$62,$C1,$D6
+        ld hl, sha1Operation_mux \ call sha1Do20Rounds \ .db 0x5A,0x82,0x79,0x99
+        ld hl, sha1Operation_xor \ call sha1Do20Rounds \ .db 0x6E,0xD9,0xEB,0xA1
+        ld hl, sha1Operation_maj \ call sha1Do20Rounds \ .db 0x8F,0x1B,0xBC,0xDC
+        ld hl, sha1Operation_xor \ call sha1Do20Rounds \ .db 0xCA,0x62,0xC1,0xD6
 
         ;    Add this chunk's hash to result so far
         ;    h0 += a

src/boot/base.asm

@@ -1,7 +1,7 @@
 #include "constants.asm"
 ; Dummy boot page to get emulators to boot the OS
     jr _
-    .fill 0x0F - $
+    .block 0x0F - $
     .db "Emulated", 0
 _:
     in a, (PORT_FLASHRAMSIZE)