boot/efi: Begin working on loading kernel_arm

Change-Id: I5c71f061fab2215f3978a39d87c2d2a686a2c7bc
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3107
Reviewed-by: Adrien Destugues <[email protected]>

src/system/boot/arch/arm/Jamfile

@@ -39,7 +39,6 @@ for platform in [ MultiBootSubDirSetup u-boot efi ] {
 			$(kernelArchSources)
 
 			arch_cpu.cpp
-			arch_start_kernel.S
 
 			# Reuse a subset of kernel debugging.
 			kernel_stubs.cpp

src/system/boot/platform/efi/arch/arm/Jamfile

@@ -11,7 +11,7 @@ for platform in [ MultiBootSubDirSetup efi ] {
 
 	local arch_src =
 		crt0-efi-$(TARGET_ARCH).S
-		#entry.S
+		entry.S
 		relocation_func.cpp
 		arch_smp.cpp
 		arch_start.cpp

src/system/boot/platform/efi/arch/arm/arch_start.cpp

@@ -8,9 +8,90 @@
 #include <boot/stage2.h>
 #include <boot/stdio.h>
 
+#include "efi_platform.h"
+
+
+extern "C" void arch_enter_kernel(struct kernel_args *kernelArgs,
+	addr_t kernelEntry, addr_t kernelStackTop);
 
 void
 arch_start_kernel(addr_t kernelEntry)
 {
-	// Kernel Entry!
+	// Prepare to exit EFI boot services.
+	// Read the memory map.
+	// First call is to determine the buffer size.
+	size_t memory_map_size = 0;
+	efi_memory_descriptor dummy;
+	efi_memory_descriptor *memory_map;
+	size_t map_key;
+	size_t descriptor_size;
+	uint32_t descriptor_version;
+	if (kBootServices->GetMemoryMap(&memory_map_size, &dummy, &map_key,
+			&descriptor_size, &descriptor_version) != EFI_BUFFER_TOO_SMALL) {
+		panic("Unable to determine size of system memory map");
+	}
+
+	// Allocate a buffer twice as large as needed just in case it gets bigger
+	// between calls to ExitBootServices.
+	size_t actual_memory_map_size = memory_map_size * 2;
+	memory_map
+		= (efi_memory_descriptor *)kernel_args_malloc(actual_memory_map_size);
+
+	if (memory_map == NULL)
+		panic("Unable to allocate memory map.");
+
+	// Read (and print) the memory map.
+	memory_map_size = actual_memory_map_size;
+	if (kBootServices->GetMemoryMap(&memory_map_size, memory_map, &map_key,
+			&descriptor_size, &descriptor_version) != EFI_SUCCESS) {
+		panic("Unable to fetch system memory map.");
+	}
+
+	addr_t addr = (addr_t)memory_map;
+	dprintf("System provided memory map:\n");
+	for (size_t i = 0; i < memory_map_size / descriptor_size; ++i) {
+		efi_memory_descriptor *entry
+			= (efi_memory_descriptor *)(addr + i * descriptor_size);
+		dprintf("  %#lx-%#lx  %#lx %#x %#lx\n", entry->PhysicalStart,
+			entry->PhysicalStart + entry->NumberOfPages * B_PAGE_SIZE,
+			entry->VirtualStart, entry->Type, entry->Attribute);
+	}
+
+	// Attempt to fetch the memory map and exit boot services.
+	// This needs to be done in a loop, as ExitBootServices can change the
+	// memory map.
+	// Even better: Only GetMemoryMap and ExitBootServices can be called after
+	// the first call to ExitBootServices, as the firmware is permitted to
+	// partially exit. This is why twice as much space was allocated for the
+	// memory map, as it's impossible to allocate more now.
+	// A changing memory map shouldn't affect the generated page tables, as
+	// they only needed to know about the maximum address, not any specific
+	// entry.
+	dprintf("Calling ExitBootServices. So long, EFI!\n");
+	while (true) {
+		if (kBootServices->ExitBootServices(kImage, map_key) == EFI_SUCCESS) {
+			// The console was provided by boot services, disable it.
+			stdout = NULL;
+			stderr = NULL;
+			// Can we adjust gKernelArgs.platform_args.serial_base_ports[0]
+			// to something fixed in qemu for debugging?
+			break;
+		}
+
+		memory_map_size = actual_memory_map_size;
+		if (kBootServices->GetMemoryMap(&memory_map_size, memory_map, &map_key,
+				&descriptor_size, &descriptor_version) != EFI_SUCCESS) {
+			panic("Unable to fetch system memory map.");
+		}
+	}
+
+	// Update EFI, generate final kernel physical memory map, etc.
+	//arch_mmu_post_efi_setup(memory_map_size, memory_map,
+	//		descriptor_size, descriptor_version);
+
+	//smp_boot_other_cpus(final_pml4, kernelEntry);
+
+	// Enter the kernel!
+	arch_enter_kernel(&gKernelArgs, kernelEntry,
+		gKernelArgs.cpu_kstack[0].start + gKernelArgs.cpu_kstack[0].size);
 }

src/system/boot/platform/efi/arch/arm/entry.S

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2011, François Revol <revol@free.fr>.
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+#include <asm_defs.h>
+
+
+	.text
+
+/*	status_t arch_enter_kernel(struct kernel_args *kernelArgs,
+		addr_t kernelEntry, addr_t kernelStackTop);
+
+	r0	- kernelArgs
+	r1	- kernelEntry
+	r2	- kernelStackTop
+*/
+FUNCTION(arch_enter_kernel):
+
+	// set the kernel stack
+	mov		sp,r2
+
+	// set up kernel _start args
+	//mov	r0,r0	// kernelArgs
+	mov		r4,r1
+	mov		r1,#0	// currentCPU=0
+
+	// call the kernel
+	mov		pc,r4
+
+	// return
+	mov		r0,#-1	// B_ERROR
+	mov		pc,lr
+
+FUNCTION_END(arch_enter_kernel)
+

src/system/boot/platform/efi/arch/x86_64/arch_start.cpp

@@ -73,7 +73,7 @@ arch_start_kernel(addr_t kernelEntry)
 		efi_memory_descriptor *entry
 			= (efi_memory_descriptor *)(addr + i * descriptor_size);
 		dprintf("  %#lx-%#lx  %#lx %#x %#lx\n", entry->PhysicalStart,
-			entry->PhysicalStart + entry->NumberOfPages * 4096,
+			entry->PhysicalStart + entry->NumberOfPages * B_PAGE_SIZE,
 			entry->VirtualStart, entry->Type, entry->Attribute);
 	}
 

src/system/boot/platform/u-boot/arch/arm/Jamfile

@@ -17,6 +17,9 @@ BootMergeObject boot_platform_u-boot_arm.o :
 	# must come first to have _start_* at correct locations
 	shell.S
 
+	# Kernel entry calls
+	arch_start_kernel.S
+
 	# Framebuffer drivers
 	arch_framebuffer_920.cpp
 	arch_framebuffer_bcm2835.cpp