From 24795891ecbde45263cb24f84036a5f314329b6e Mon Sep 17 00:00:00 2001
From: CTCaer <ctcaer@gmail.com>
Date: Mon, 19 Dec 2022 04:31:54 +0200
Subject: [PATCH] loader: refactor

---
 loader/Makefile |  2 +-
 loader/link.ld  |  8 ++++++++
 loader/loader.c | 39 ++++++++++++++++++++-------------------
 3 files changed, 29 insertions(+), 20 deletions(-)

diff --git a/loader/Makefile b/loader/Makefile
index d59ed08..522ddee 100644
--- a/loader/Makefile
+++ b/loader/Makefile
@@ -30,7 +30,7 @@ CUSTOMDEFINES := -DBL_MAGIC=$(IPL_MAGIC)
 CUSTOMDEFINES += -DBL_VER_MJ=$(BLVERSION_MAJOR) -DBL_VER_MN=$(BLVERSION_MINOR) -DBL_VER_HF=$(BLVERSION_HOTFX) -DBL_RESERVED=$(BLVERSION_RSVD)
 
 #TODO: Considering reinstating some of these when pointer warnings have been fixed.
-WARNINGS := -Wall -Wno-array-bounds -Wno-stringop-overflow
+WARNINGS := -Wall -Wsign-compare -Wno-array-bounds -Wno-stringop-overflow
 
 ARCH := -march=armv4t -mtune=arm7tdmi -mthumb-interwork
 CFLAGS = $(ARCH) -O2 -g -nostdlib -ffunction-sections -fdata-sections -fomit-frame-pointer -std=gnu11 $(WARNINGS) $(CUSTOMDEFINES)
diff --git a/loader/link.ld b/loader/link.ld
index b217fd3..81e1085 100644
--- a/loader/link.ld
+++ b/loader/link.ld
@@ -15,6 +15,14 @@ SECTIONS {
 		*(.rodata*);
 		*(._payload_00);
 		*(._payload_01);
+
+		/*
+		 * To mitigate bad injectors/chainloaders,
+		 * miss-align binary size to account for version info.
+		 * !If version text is not appended, then use ". = ALIGN(4)"!
+		 */
+		 data_end_ua = .;
+		 . = ((data_end_ua + 0x6 + 4 - 1) & ~(4 - 1)) - 6;
 	}
 	__ldr_end = .;
 	. = ALIGN(0x10);
diff --git a/loader/loader.c b/loader/loader.c
index fc1a1f7..7cff34e 100644
--- a/loader/loader.c
+++ b/loader/loader.c
@@ -60,39 +60,40 @@ const volatile char __attribute__((section ("._octopus"))) octopus[] =
 void loader_main()
 {
 	// Preliminary BPMP clocks init.
-	CLOCK(CLK_RST_CONTROLLER_CLK_SYSTEM_RATE) = 0x10;          // Set HCLK div to 2 and PCLK div to 1.
-	CLOCK(CLK_RST_CONTROLLER_CLK_SOURCE_SYS) = 0;              // Set SCLK div to 1.
-	CLOCK(CLK_RST_CONTROLLER_SCLK_BURST_POLICY) = 0x20004444;  // Set clk source to Run and PLLP_OUT2 (204MHz).
+	CLOCK(CLK_RST_CONTROLLER_CLK_SYSTEM_RATE)    = 0x10;       // Set HCLK div to 2 and PCLK div to 1.
+	CLOCK(CLK_RST_CONTROLLER_CLK_SOURCE_SYS)     = 0;          // Set SCLK div to 1.
+	CLOCK(CLK_RST_CONTROLLER_SCLK_BURST_POLICY)  = 0x20004444; // Set clk source to Run and PLLP_OUT2 (204MHz).
 	CLOCK(CLK_RST_CONTROLLER_SUPER_SCLK_DIVIDER) = 0x80000000; // Enable SUPER_SDIV to 1.
-	CLOCK(CLK_RST_CONTROLLER_CLK_SYSTEM_RATE) = 2;             // Set HCLK div to 1 and PCLK div to 3.
-	CLOCK(CLK_RST_CONTROLLER_SCLK_BURST_POLICY) = 0x20003333;  // Set SCLK to PLLP_OUT (408MHz).
+	CLOCK(CLK_RST_CONTROLLER_CLK_SYSTEM_RATE)    = 2;          // Set HCLK div to 1 and PCLK div to 3.
+	CLOCK(CLK_RST_CONTROLLER_SCLK_BURST_POLICY)  = 0x20003333; // Set SCLK to PLLP_OUT (408MHz).
 
-	// Get Loader and Payload size.
-	u32 payload_size = sizeof(payload_00) + sizeof(payload_01);             // Actual payload size.
-	payload_size += (u32)payload_01 - (u32)payload_00 - sizeof(payload_00); // Add array alignment.
+	// Get Payload size.
+	u32 payload_size  = sizeof(payload_00) + sizeof(payload_01);                // Actual payload size.
+	payload_size     += (u32)payload_01 - (u32)payload_00 - sizeof(payload_00); // Add compiler alignment.
+	payload_size      = ALIGN(payload_size, 4);                                 // Align size to 4 bytes.
 	u32 *payload_addr = (u32 *)payload_00;
 
 	// Relocate payload to a safer place.
-	u32 bytes = ALIGN(payload_size, 4) >> 2;
-	u32 *addr = payload_addr + bytes - 1;
-	u32 *dst = (u32 *)(IPL_RELOC_TOP - 4);
-	while (bytes)
+	u32 words = payload_size >> 2;
+	u32 *src  = payload_addr + words - 1;
+	u32 *dst  = (u32 *)(IPL_RELOC_TOP - 4);
+	while (words)
 	{
-		*dst = *addr;
+		*dst = *src;
+		src--;
 		dst--;
-		addr--;
-		bytes--;
+		words--;
 	}
 
 	// Set source address of the first part.
-	u8 *src_addr = (void *)(IPL_RELOC_TOP - ALIGN(payload_size, 4));
+	u8 *src_addr = (void *)(IPL_RELOC_TOP - payload_size);
 	// Uncompress first part.
-	u32 dst_pos = LZ_Uncompress((const u8 *)src_addr, (u8*)IPL_LOAD_ADDR, sizeof(payload_00));
+	u32 dst_pos = LZ_Uncompress((const u8 *)src_addr, (u8 *)IPL_LOAD_ADDR, sizeof(payload_00));
 
-	// Set source address of the second part. Includes array alignment.
+	// Set source address of the second part. Includes compiler alignment.
 	src_addr += (u32)payload_01 - (u32)payload_00;
 	// Uncompress second part.
-	LZ_Uncompress((const u8 *)src_addr, (u8*)IPL_LOAD_ADDR + dst_pos, sizeof(payload_01));
+	LZ_Uncompress((const u8 *)src_addr, (u8 *)IPL_LOAD_ADDR + dst_pos, sizeof(payload_01));
 
 	// Copy over boot configuration storage.
 	memcpy((u8 *)(IPL_LOAD_ADDR + IPL_PATCHED_RELOC_SZ), &b_cfg, sizeof(boot_cfg_t));