Revert "Allocate initialized sections for EWRAM and IWRAM (#3877)" (#3891)

This reverts commit f24deb9301.

Makefile

@@ -473,7 +473,7 @@ endif
 $(OBJ_DIR)/ld_script.ld: $(LD_SCRIPT) $(LD_SCRIPT_DEPS)
 	cd $(OBJ_DIR) && sed "s#tools/#../../tools/#g" ../../$(LD_SCRIPT) > ld_script.ld
 
-LDFLAGS = -Map ../../$(MAP) --no-warn-rwx-segments
+LDFLAGS = -Map ../../$(MAP)
 $(ELF): $(OBJ_DIR)/ld_script.ld $(OBJS) libagbsyscall
 	@echo "cd $(OBJ_DIR) && $(LD) $(LDFLAGS) -T ld_script.ld -o ../../$@ <objects> <lib>"
 	@cd $(OBJ_DIR) && $(LD) $(LDFLAGS) -T ld_script.ld --print-memory-usage -o ../../$@ $(OBJS_REL) $(LIB) | cat

include/crt0.h

@@ -3,6 +3,4 @@
 
 extern u32 IntrMain[];
 
-extern void ReInitializeEWRAM();
-
 #endif //GUARD_CRT0_H

include/gba/defines.h

@@ -6,10 +6,8 @@
 #define TRUE  1
 #define FALSE 0
 
-#define IWRAM_DATA __attribute__((section(".bss")))
+#define IWRAM_DATA __attribute__((section("iwram_data")))
-#define EWRAM_DATA __attribute__((section(".sbss")))
+#define EWRAM_DATA __attribute__((section("ewram_data")))
-#define IWRAM_INIT __attribute__((section(".iwram")))
-#define EWRAM_INIT __attribute__((section(".ewram")))
 #define UNUSED __attribute__((unused))
 
 #if MODERN

ld_script.ld

@@ -13,35 +13,19 @@ MEMORY
 
 SECTIONS {
 
-    .ewram ORIGIN(EWRAM) : AT (__ewram_lma)
+    ewram 0x2000000 (NOLOAD) :
-    ALIGN(4)
-    {
-        __ewram_start = .;
-        *(.ewram*)
-        __ewram_end = .;
-    } > EWRAM
-
-    .ewram.sbss (NOLOAD) :
     ALIGN(4)
     {
         INCLUDE "sym_ewram.ld"
-        src/*.o(.sbss);
+        src/*.o(ewram_data);
-        gflib/*.o(.sbss);
+        gflib/*.o(ewram_data);
 
         *libc.a:impure.o(.data);
         *libc.a:locale.o(.data);
         *libc.a:mallocr.o(.data);
     } > EWRAM
 
-    .iwram ORIGIN(IWRAM) : AT (__iwram_lma)
+    iwram 0x3000000 (NOLOAD) :
-    ALIGN(4)
-    {
-        __iwram_start = .;
-        *(.iwram*);
-        __iwram_end = .;
-    } > IWRAM
-
-    .iwram.bss (NOLOAD) :
     ALIGN(4)
     {
         /* .bss starts at 0x3000000 */
@@ -1340,20 +1324,6 @@ SECTIONS {
         data/*.o(.rodata);
     } > ROM = 0
 
-    .data.iwram :
-    ALIGN(4)
-    {
-        __iwram_lma = .;
-        . = . + (__iwram_end - __iwram_start);
-    } > ROM = 0
-
-    .data.ewram :
-    ALIGN(4)
-    {
-        __ewram_lma = .;
-        . = . + (__ewram_end - __ewram_start);
-    } > ROM = 0
-
     __rom_end = .;
 
     /* DWARF debug sections.

ld_script_modern.ld

@@ -12,32 +12,15 @@ MEMORY
 }
 
 SECTIONS {
-
+    ewram 0x2000000 (NOLOAD) :
-
-    .ewram ORIGIN(EWRAM) : AT (__ewram_lma)
     ALIGN(4)
     {
-        __ewram_start = .;
+        src/*.o(ewram_data);
-        *(.ewram*)
+        gflib/*.o(ewram_data);
-        __ewram_end = .;
+
     } > EWRAM
 
-    .ewram.sbss (NOLOAD) :
+    iwram 0x3000000 (NOLOAD) :
-    ALIGN(4)
-    {
-        src/*.o(.sbss);
-        gflib/*.o(.sbss);
-    } > EWRAM
-
-    .iwram ORIGIN(IWRAM) : AT (__iwram_lma)
-    ALIGN(4)
-    {
-        __iwram_start = .;
-        *(.iwram*);
-        __iwram_end = .;
-    } > IWRAM
-
-    .iwram.bss (NOLOAD) :
     ALIGN(4)
     {
         src/*.o(.bss);
@@ -55,8 +38,9 @@ SECTIONS {
     } > IWRAM
 
     /* BEGIN ROM DATA */
+    . = 0x8000000;
 
-    .text ORIGIN(ROM) :
+    .text :
     ALIGN(4)
     {
         src/rom_header.o(.text*);
@@ -141,20 +125,6 @@ SECTIONS {
         src/graphics.o(.rodata);
     } > ROM =0
 
-    .data.iwram :
-    ALIGN(4)
-    {
-        __iwram_lma = .;
-        . = . + (__iwram_end - __iwram_start);
-    } > ROM = 0
-
-    .data.ewram :
-    ALIGN(4)
-    {
-        __ewram_lma = .;
-        . = . + (__ewram_end - __ewram_start);
-    } > ROM = 0
-
     __rom_end = .;
 
     /* DWARF debug sections.

ld_script_test.ld

@@ -12,32 +12,15 @@ MEMORY
 }
 
 SECTIONS {
-
+    ewram 0x2000000 (NOLOAD) :
-    .ewram ORIGIN(EWRAM) : AT (__ewram_lma)
     ALIGN(4)
     {
-        __ewram_start = .;
+        src/*.o(ewram_data);
-        *(.ewram*)
+        gflib/*.o(ewram_data);
-        __ewram_end = .;
+        test/*.o(ewram_data);
     } > EWRAM
 
-    .ewram.sbss (NOLOAD) :
+    iwram 0x3000000 (NOLOAD) :
-    ALIGN(4)
-    {
-        src/*.o(.sbss);
-        gflib/*.o(.sbss);
-        test/*.o(.sbss);
-    } > EWRAM
-
-    .iwram ORIGIN(IWRAM) : AT (__iwram_lma)
-    ALIGN(4)
-    {
-        __iwram_start = .;
-        *(.iwram*);
-        __iwram_end = .;
-    } > IWRAM
-
-    .iwram.sbss (NOLOAD) :
     ALIGN(4)
     {
         src/*.o(.bss);
@@ -114,20 +97,6 @@ SECTIONS {
         src/libisagbprn.o(.rodata);
     } > ROM =0
 
-    .data.iwram :
-    ALIGN(4)
-    {
-        __iwram_lma = .;
-        . = . + (__iwram_end - __iwram_start);
-    } > ROM = 0
-
-    .data.ewram :
-    ALIGN(4)
-    {
-        __ewram_lma = .;
-        . = . + (__ewram_end - __ewram_start);
-    } > ROM = 0
-
     tests :
     ALIGN(4)
     {

src/crt0.s

@@ -6,28 +6,22 @@
 
 	.align 2, 0
 Init::
-@ Set up location for IRQ stack
 	mov r0, #PSR_IRQ_MODE
 	msr cpsr_cf, r0
 	ldr sp, sp_irq
-@ Set up location for system stack
 	mov r0, #PSR_SYS_MODE
 	msr cpsr_cf, r0
 	ldr sp, sp_sys
-@ Prepare for interrupt handling
 	ldr r1, =INTR_VECTOR
 	adr r0, IntrMain
 	str r0, [r1]
-@ Dispatch memory reset request to hardware
+	.if MODERN
 	mov r0, #255 @ RESET_ALL
 	svc #1 << 16
-@ Fill RAM areas with appropriate data
+	.endif @ MODERN
-	bl InitializeWorkingMemory
-@ Jump to AgbMain
 	ldr r1, =AgbMain + 1
 	mov lr, pc
 	bx r1
-@ Re-init if AgbMain exits
 	b Init
 
 	.align 2, 0
@@ -130,54 +124,3 @@ IntrMain_RetAddr:
 	.pool
 
 	.align 2, 0 @ Don't pad with nop.
-
-@ Fills initialized IWRAM and EWRAM sections in RAM from LMA areas in ROM
-InitializeWorkingMemory:
-	push {r0-r3,lr}
-	ldr r0, =__iwram_lma
-	ldr r1, =__iwram_start
-	ldr r2, =__iwram_end
-	cmp r1, r2
-	beq skip_iwram_copy
-	bl CopyMemory_DMA
-skip_iwram_copy:
-	ldr r0, =__ewram_lma
-	ldr r1, =__ewram_start
-	ldr r2, =__ewram_end
-	cmp r1, r2
-	beq skip_ewram_copy
-	bl CopyMemory_DMA
-skip_ewram_copy:
-	pop {r0-r3,lr}
-	bx lr
-
-@ Uses a DMA transfer to load from r0 into r1 until r2
-CopyMemory_DMA:
-	subs r2, r2, r1
-	lsr r2, r2, #2
-	mov r4, #0x80000000
-	orr r4, r4, #(1 << 26)
-	orr r2, r2, r4
-	ldr r3, =REG_DMA3
-	stmia r3, {r0, r1, r2}
-	bx lr
-
-.thumb
-@ Called from C code to reinitialize working memory after a link connection failure
-ReInitializeEWRAM::
-	ldr r0, =__ewram_lma
-	ldr r1, =__ewram_start
-	ldr r2, =__ewram_end
-	cmp r1, r2
-	beq EndReinitializeEWRAM
-	subs r2, r1
-	movs r3, #1
-	lsls r3, r3, #26
-	orrs r2, r2, r3
-	swi 0x0B
-EndReinitializeEWRAM:
-	bx lr
-
-	.pool
-
-	.align 2, 0 @ Don't pad with nop.

src/main.c

@@ -93,6 +93,11 @@ void EnableVCountIntrAtLine150(void);
 
 void AgbMain()
 {
+    // Modern compilers are liberal with the stack on entry to this function,
+    // so RegisterRamReset may crash if it resets IWRAM.
+#if !MODERN
+    RegisterRamReset(RESET_ALL);
+#endif //MODERN
     *(vu16 *)BG_PLTT = RGB_WHITE; // Set the backdrop to white on startup
     InitGpuRegManager();
     REG_WAITCNT = WAITCNT_PREFETCH_ENABLE | WAITCNT_WS0_S_1 | WAITCNT_WS0_N_3;

src/reload_save.c

@@ -1,6 +1,5 @@
 #include "global.h"
 #include "main.h"
-#include "crt0.h"
 #include "gpu_regs.h"
 #include "m4a.h"
 #include "load_save.h"
@@ -16,7 +15,6 @@ void ReloadSave(void)
     u16 imeBackup = REG_IME;
     REG_IME = 0;
     RegisterRamReset(RESET_EWRAM);
-    ReInitializeEWRAM();
     ClearGpuRegBits(REG_OFFSET_DISPCNT, DISPCNT_FORCED_BLANK);
     REG_IME = imeBackup;
     gMain.inBattle = FALSE;