[fw-isoldr] Move loader address to Makefile and cleanup for startup.

Also impove params getting.

Author: DC-SWAT

firmware/isoldr/loader/Makefile.cfg

@@ -4,7 +4,7 @@
 # (c) 2009-2025 SWAT
 #
 
-TARGET = 0x8ce00000
+TARGET = 0x8ce00400
 BUILD = build
 VERSION = "0.8.4"
 INSTALL_PATH = ../../../build/firmware/isoldr
@@ -38,14 +38,14 @@ TARGETOBJCOPY	= $(TARGETPREFIX)-objcopy
 TARGETLD		= $(TARGETPREFIX)-ld
 TARGETAS		= $(TARGETPREFIX)-as
 TARGETSIZE		= $(TARGETPREFIX)-size
-TARGETLDFLAGS	= -Wl,--gc-sections -Wl,--no-warn-rwx-segments -Tshlelf.xc \
+TARGETLDFLAGS	= -Wl,--gc-sections -Wl,--no-warn-rwx-segments \
+					-Tshlelf.xc -Ttext=$(TARGET) \
 					-nostartfiles -nostdlib -nodefaultlibs
 TARGETCFLAGS	= -ml -m4-single-only -ffunction-sections -fdata-sections -ffreestanding \
 					-fno-builtin -fno-strict-aliasing -fomit-frame-pointer \
 					-freorder-blocks-algorithm=simple -flto=auto \
 					-Wall -std=c17 -Wextra -Werror \
 					-D__DREAMCAST__ \
-					-DLOADER_ADDR=$(TARGET) \
 					-DVERSION=\"$(VERSION)\"
 
 LIBS = -lgcc

firmware/isoldr/loader/main.c

@@ -11,8 +11,7 @@
 #include <maple.h>
 
 isoldr_info_t *IsoInfo;
-uint32 loader_addr = 0;
-uint32 loader_end = 0;
+uint32 loader_end;
 
 int main(int argc, char *argv[]) {
 
@@ -23,9 +22,8 @@ int main(int argc, char *argv[]) {
 		bfont_saved_addr = 0xa0001000;
 	}
 
-	IsoInfo = (isoldr_info_t *)LOADER_ADDR;
-	loader_addr = (uint32)IsoInfo;
 	loader_end = loader_addr + loader_size + ISOLDR_PARAMS_SIZE + 32;
+	IsoInfo = (isoldr_info_t *)(loader_addr - ISOLDR_PARAMS_SIZE);
 
 	OpenLog();
 	printf(NULL);
@@ -86,10 +84,11 @@ int main(int argc, char *argv[]) {
 		IsoInfo->boot_mode
 	);
 
-	LOGF("Loader: %08lx - %08lx size %d, heap %08lx\n", 
+	LOGF("Loader: %08lx - %08lx size %d, params %08lx, heap %08lx\n", 
 		loader_addr,
 		loader_addr + loader_size,
 		loader_size + ISOLDR_PARAMS_SIZE,
+		(uint32)IsoInfo,
 		malloc_heap_pos()
 	);
 
@@ -100,7 +99,7 @@ int main(int argc, char *argv[]) {
 		goto error;
 	}
 
-	if (!IsoInfo->use_dma) {
+	if(!IsoInfo->use_dma) {
 		fs_enable_dma(FS_DMA_DISABLED);
 	}
 

firmware/isoldr/loader/shlelf.xc

@@ -9,11 +9,9 @@ OUTPUT_FORMAT("elf32-shl", "elf32-shl",
 	      "elf32-shl")
 OUTPUT_ARCH(sh)
 ENTRY(start)
-SEARCH_DIR("/opt/toolchains/dc/sh-elf/sh-elf/lib");
 SECTIONS
 {
   /* Read-only sections, merged into text segment: */
-  PROVIDE (__executable_start = 0x8ce00400); . = 0x8ce00400;
   .text           :
   {
     *(.text .stub .text.* .gnu.linkonce.t.*)

firmware/isoldr/loader/startup.s

@@ -1,5 +1,5 @@
 !   This file is part of DreamShell ISO Loader
-!   Copyright (C) 2009-2016 SWAT <http://www.dc-swat.ru>
+!   Copyright (C) 2009-2016, 2025 SWAT <http://www.dc-swat.ru>
 !   Based on Sylverant PSO Patcher code by Lawrence Sebald
 !
 !   This program is free software: you can redistribute it and/or modify
@@ -15,6 +15,14 @@
 !   along with this program. If not, see <http://www.gnu.org/licenses/>.
 !
     .globl      start
+    .globl      _loader_addr
+    .globl      _loader_size
+    .globl      _bios_patch_base
+    .globl      _bios_patch_handler
+    .globl      _bios_patch_end
+    .globl      _boot_stub
+    .globl      _boot_stub_len
+
     .text
 start:
     ! First, make sure to run in the P2 area
@@ -59,7 +67,7 @@ init:
     jmp         @r0
     mov         #0, r0
 
-    .align      2
+    .align      4
 mainaddr:
     .long       _main
 initaddr:
@@ -74,36 +82,31 @@ p2_mask:
     .long       0xa0000000
 stack_ptr:
     .long       0x8d000000
-
-    .globl      _loader_size
+_loader_addr:
+    .long       start
 _loader_size:
     .long       _end - start
-	
+_boot_stub_len:
+    .long       _boot_stub_len - _boot_stub
+
+    .align 2
 bios_patch_null:
     nop
     rts
     nop
 
-    .globl  _bios_patch_base
 _bios_patch_base:
-!    nop
-!    mov.l   r0, @-r15
     mov.l   _bios_patch_handler, r0
     jmp     @r0
-!    mov.l   @r15+, r0
-!    nop
-	
+
     .align  4
-    .globl  _bios_patch_handler
 _bios_patch_handler:
     .long   bios_patch_null
-    .globl  _bios_patch_end
 _bios_patch_end:
 
 	.align 2
     ! This MUST always be run from a non-cacheable area of memory, since it
     ! messes with the CCR register.
-    .globl      _boot_stub
 _boot_stub:
     ! Set up some registers we will need to deal with later...
     mov         r4, r14
@@ -145,7 +148,10 @@ _boot_stub:
     mov         #0, r14
     ! We should not ever get back here.
 
-    .balign     4
+    .align 2
+ccr_data:
+    .word       0x0909
+    .align     4
 ccr_addr:
     .long       0xff00001c
 newr15:
@@ -162,10 +168,3 @@ startaddr:
     .long       start
 p2mask:
     .long       0xa0000000
-ccr_data:
-    .word       0x0909
-
-    .globl      _boot_stub_len
-    .balign     4
-_boot_stub_len:
-    .long       _boot_stub_len - _boot_stub