Add payload

PAYLOAD/build.sh

@@ -0,0 +1,14 @@
+echo "Building payload"
+
+ee-gcc -Ttext=0x01FFF800 payload.c -o payload.elf -nostartfiles -nostdlib -ffreestanding -Os -Wl,-z,max-page-size=0x1 # 2048
+ee-objcopy -O binary payload.elf payload.bin -Wl,-z,max-page-size=0x1
+
+ENTRY=`ee-objdump -t payload.elf | grep " _start"`
+ENTRY=0x`grep -o "^\S*" <<< $ENTRY`
+
+echo "Building crt0"
+
+ee-gcc -Ttext=0x01500014 -DENTRY=$ENTRY crt0.S -o fullpayload.elf -nostartfiles -nostdlib -ffreestanding -Wl,-z,max-page-size=0x1
+ee-objcopy -O binary fullpayload.elf fullpayload.bin -Wl,-z,max-page-size=0x1
+
+echo "Done. Insert fullpayload.bin into VIDEO_TS.IFO at offset 0x2bb4"

PAYLOAD/crt0.S

@@ -0,0 +1,63 @@
+.set noreorder # If we're writing assembly, why would we want this?
+
+.section .text.startup
+
+.equ memcpy, 0x225668
+.equ getBufferInternal, 0x2986a0
+.equ payload, (0x2000000 - 0x800) # End of RAM
+
+.global _start
+_start:
+	#la $a0, 0x7f
+	#la $v1, 0x01
+	#syscall 0x01 # ResetEE
+
+	#la $a0, relo
+	la $a0, load
+	la $a1, 0
+	la $a2, 0
+	la $a3, 0
+
+.global ExecPS2
+ExecPS2:
+	la $v1, 7
+	syscall 7 # ExecPS2
+
+load:
+	la $a0, 0
+	la $a1, 0 # 0 = VIDEO_TS.IFO, 1 = VTS_01_0.IFO
+	la $a2, 0x3000 / 0x800 # lba offset in file
+	la $a3, payload # Destination
+	la $t0, 0x800 / 0x800 # Count
+	la $t1, 0
+	la $v0, getBufferInternal
+	jalr $v0
+	nop
+
+#relo:
+	# Relocate payload to end of RAM
+#	la $a0, (0x2000000 - 1024)
+#	la $a1, payload
+#	la $a2, 2048
+#	la $v0, memcpy
+#	jalr $v0
+
+boot:
+	la $v1, 0x64; la $a0, 0; syscall 0x64 # FlushCache data writeback
+	la $v1, 0x64; la $a0, 2; syscall 0x64 # FlushCache instruction invalidate
+
+	# Point stack to end of scratchpad RAM
+	la $sp, 0x70004000
+
+	# Execute from relocated place
+	la $v0, ENTRY
+	j $v0
+	nop
+
+.space (_start + 0x2faa - 0x2bb4) - .
+fpIndex:
+	.byte 0x7e
+	.byte 0xe0
+
+.space (_start + 0x3000 - 0x2bb4) - .
+.incbin "payload.bin"

PAYLOAD/payload.c

@@ -0,0 +1,142 @@
+#include <stddef.h>
+
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+
+#define pointToIFO ((void (*)(unsigned int index, unsigned int lba, unsigned int offset))0x25c880)
+#define getDiscData ((void (*)(unsigned int s, void *d))0x25c9f0)
+#define getDiscBuffer ((void (*)(void))0x25c678)
+
+#define sceCdSync ((void (*)(int mode))0x2a69c8)
+
+typedef struct {
+	unsigned int lsn;
+	unsigned int size;
+	char name[16];
+	unsigned char date[8];
+} sceCdlFILE;
+#define sceCdSearchFile ((int (*)(sceCdlFILE *, char *, int))0x2a6488)
+
+#define SifIopReset ((int (*)(char *, int))0x84fe0)
+#define SifIopSync ((int (*)(void))0x85110)
+#define SifInitRpc ((void (*)(int))0x84180)
+#define SifExitRpc ((void (*)(void))0x84310)
+
+#define getBufferInternal ((int (*)(void *filename, int type, int currentSector, void *dest, unsigned int sectorsRemaining, int curReadPos))0x002986a0)
+
+#define ELF_PT_LOAD 1
+
+typedef unsigned char u8;
+typedef unsigned short u16;
+typedef unsigned int u32;
+
+typedef struct {
+	u8 ident[16];
+	u16 type;
+	u16 machine;
+	u32 version;
+	u32 entry;
+	u32 phoff;
+	u32 shoff;
+	u32 flags;
+	u16 ehsize;
+	u16 phentsize;
+	u16 phnum;
+	u16 shentsize;
+	u16 shnum;
+	u16 shstrndx;
+} elf_header_t;
+
+typedef struct {
+	u32 type;
+	u32 offset;
+	void *vaddr;
+	u32 paddr;
+	u32 filesz;
+	u32 memsz;
+	u32 flags;
+	u32 align;
+} elf_pheader_t;
+
+__attribute__((noreturn)) void ExecPS2(void *entry, void *gp, int argc, char **argv) {
+	asm volatile("la $v1, 7; syscall 7");
+	//__builtin_unreachable();
+}
+
+void *memcpy_(void *dest, void *src, size_t n) { 
+   int i;
+   for(i = 0; i < n; i++) ((unsigned char *)dest)[i] = ((unsigned char *)src)[i];
+   return dest;
+}
+
+void *memset(void *dest, int c, size_t n) {
+	int i;
+	for(i = 0; i < n; i++) ((unsigned char *)dest)[i] = c;
+	return dest;
+}
+
+static void readData(void *dest, unsigned int offset, size_t n) {
+	unsigned char buffer[0x800];
+
+	unsigned int copied = 0;
+	#define remaining (n - copied)
+
+	if(offset % 0x800) {
+		getBufferInternal("", 1, offset / 0x800, buffer, 1, 0);
+		memcpy_(dest, buffer + offset % 0x800, min(0x800 - offset, n));
+		copied += min(0x800 - offset, n);
+	}
+
+	if(remaining >= 0x800) {
+		getBufferInternal("", 1, (offset + copied) / 0x800, dest + copied, remaining / 0x800, 0);
+		copied += (remaining / 0x800) * 0x800;
+	}
+	
+	if(remaining > 0) {
+		getBufferInternal("", 1, (offset + copied) / 0x800, buffer, 1, 0);
+		memcpy_(dest + copied, buffer, remaining);
+	}
+}
+
+__attribute__((noreturn)) void _start(void) {
+	//Exit(0);
+	//asm volatile("la $v1, 0x04; la $a0, 0; syscall 0x04");
+
+	int i;
+
+	// point to VTS_02_0.IFO
+	pointToIFO(2, 0, 0);
+	
+	// Force a read from VTS_02_0.IFO
+	char head[64];
+	getDiscData(64, &head);
+
+	// Based on https://github.com/AKuHAK/uLaunchELF/blob/master/loader/loader.c
+	elf_header_t eh;
+	readData(&eh, 0, sizeof(elf_header_t));
+
+	elf_pheader_t eph[eh.phnum];
+	readData(&eph, eh.phoff, sizeof(elf_pheader_t) * eh.phnum);
+	
+	for (i = 0; i < eh.phnum; i++) {
+		if (eph[i].type != ELF_PT_LOAD)
+			continue;
+
+		readData(eph[i].vaddr, eph[i].offset, eph[i].filesz);
+		if(eph[i].memsz > eph[i].filesz) memset(eph[i].vaddr + eph[i].filesz, 0, eph[i].memsz - eph[i].filesz);
+	}
+
+	asm volatile("la $v1, 0x64; la $a0, 0; syscall 0x64"); // FlushCache data writeback
+	asm volatile("la $v1, 0x64; la $a0, 2; syscall 0x64"); // FlushCache instruction invalidate
+
+	//while(!SifIopReset("", 0));
+	//while(!SifIopSync());
+
+	//while(!SifIopReset("rom0:UDNL rom0:EELOADCNF", 0));
+	SifIopReset("rom0:UDNL rom0:EELOADCNF", 0);
+	while(!SifIopSync());
+
+	SifInitRpc(0);
+	SifExitRpc();
+
+	ExecPS2((void *)eh.entry, 0, 0, 0);
+}

README.md

@@ -36,3 +36,8 @@ Once you've placed all the homebrew files you'd like into the directory, generat
 
 ## Test and burn
 I would recommend you test in PCSX2 first, but since [PCSX2 doesn't support loading the DVD Player](https://github.com/PCSX2/pcsx2/issues/1981), you have to decrypt and repack it yourself, which can be a pain.
+
+## Replacing loader payload
+If you wish to work on the loader payload, see run `build.sh` inside `PAYLOAD` directory, and copy the output `fullpayload.bin` to `VIDEO_TS/VIDEO_TS.IFO` at offset `0x2bb4`.
+
+The default loader will boot `VIDEO_TS/VTS_02_0.IFO` as an ELF file, but tweaks might be desired to improve compatibility.