fusee-cpp: add basic structural stubs

fusee_cpp/loader_stub/source/fusee_loader_error.cpp

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <exosphere.hpp>
+#include "fusee_loader_error.hpp"
+
+namespace ams::diag {
+
+    NORETURN void AbortImpl(const char *file, int line, const char *func, const char *expr, u64 value, const char *format, ...) {
+        AMS_UNUSED(file, line, func, expr, value, format);
+        ams::nxboot::loader::ErrorStop();
+    }
+
+    NORETURN void AbortImpl(const char *file, int line, const char *func, const char *expr, u64 value) {
+        AMS_UNUSED(file, line, func, expr, value);
+        ams::nxboot::loader::ErrorStop();
+    }
+
+    NORETURN void AbortImpl() {
+        ams::nxboot::loader::ErrorStop();
+    }
+
+}
+
+namespace ams::nxboot::loader {
+
+    NORETURN void ErrorStop() {
+        /* Halt ourselves. */
+        while (true) {
+            reg::Write(secmon::MemoryRegionPhysicalDeviceFlowController.GetAddress() + FLOW_CTLR_HALT_COP_EVENTS, FLOW_REG_BITS_ENUM(HALT_COP_EVENTS_MODE, FLOW_MODE_STOP),
+                                                                                                                  FLOW_REG_BITS_ENUM(HALT_COP_EVENTS_JTAG,        ENABLED));
+        }
+    }
+
+}

fusee_cpp/loader_stub/source/fusee_loader_error.hpp

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <exosphere.hpp>
+#pragma once
+
+namespace ams::nxboot::loader {
+
+    NORETURN void ErrorStop();
+
+}

fusee_cpp/loader_stub/source/fusee_loader_main.cpp

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <exosphere.hpp>
+#include "fusee_loader_uncompress.hpp"
+#include "program_lz4.h"
+
+namespace ams::nxboot::loader {
+
+    namespace {
+
+        constexpr uintptr_t ProgramImageBase = 0x40001000;
+        constexpr uintptr_t ProgramImageEnd  = 0x4003D000;
+        constexpr size_t ProgramImageSizeMax = ProgramImageEnd - ProgramImageBase;
+
+        void CopyBackwards(void *dst, const void *src, size_t size) {
+            /* We want to copy 32-bits at a time from destination to source. */
+            const size_t words = util::DivideUp(size, sizeof(u32));
+
+            /* Convert to 32-bit pointers. */
+                  u32 *dst_32 = static_cast<u32 *>(dst) + words;
+            const u32 *src_32 = static_cast<const u32 *>(src) + words;
+
+            /* Copy data. */
+            for (size_t i = 0; i < words; ++i) {
+                *(--dst_32) = *(--src_32);
+            }
+        }
+
+    }
+
+    NORETURN void UncompressAndExecute(const void *program, size_t program_size) {
+        /* Relocate the compressed binary to a place where we can safely decompress it. */
+        void *relocated_program = reinterpret_cast<void *>(util::AlignDown(ProgramImageEnd - program_size, sizeof(u32)));
+        if (relocated_program != program) {
+            CopyBackwards(relocated_program, program, program_size);
+        }
+
+        /* Uncompress the program image. */
+        Uncompress(reinterpret_cast<void *>(ProgramImageBase), ProgramImageSizeMax, relocated_program, program_size);
+
+        /* Jump to the boot image. */
+        reinterpret_cast<void (*)()>(ProgramImageBase)();
+
+        /* We will never reach this point. */
+        __builtin_unreachable();
+    }
+
+}

fusee_cpp/loader_stub/source/fusee_loader_start.s

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+
+.section .crt0._ZN3ams6nxboot6loader5StartEv, "ax", %progbits
+.arm
+.align 5
+.global _ZN3ams6nxboot6loader5StartEv
+.type   _ZN3ams6nxboot6loader5StartEv, %function
+_ZN3ams6nxboot6loader5StartEv:
+    /* Switch to system mode, mask all interrupts, clear all flags */
+    msr cpsr_cxsf, #0xDF
+
+    /* Relocate loader stub. */
+    ldr r0, =_ZN3ams6nxboot6loader5StartEv
+    adr r1, _ZN3ams6nxboot6loader5StartEv
+    ldr r2, =__loader_stub_lma__
+    sub r2, r2, r0
+    add r2, r2, r1
+
+    ldr r3, =__loader_stub_start__
+    ldr r4, =__loader_stub_end__
+    sub r4, r4, r3
+    0:
+        ldmia r2!, {r5-r12}
+        stmia r3!, {r5-r12}
+        subs  r4, #0x20
+        bne 0b
+
+    /* Set the stack pointer */
+    ldr  sp, =0x40001000
+    mov  fp, #0
+
+    /* Generate arguments. */
+    ldr r3, =program_lz4
+    ldr r4, =program_lz4_end
+    sub r4, r4, r3
+    sub r3, r3, r0
+    add r3, r3, r1
+    mov r0, r3
+    mov r1, r4
+
+    /* Jump to the loader stub. */
+    ldr r3, =_ZN3ams6nxboot6loader20UncompressAndExecuteEPKvj
+    bx  r3

fusee_cpp/loader_stub/source/fusee_loader_uncompress.cpp

@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <exosphere.hpp>
+#include "fusee_loader_uncompress.hpp"
+
+namespace ams::nxboot::loader {
+
+    namespace {
+
+        class Lz4Uncompressor {
+            private:
+                const u8 *src;
+                size_t src_size;
+                size_t src_offset;
+                u8 *dst;
+                size_t dst_size;
+                size_t dst_offset;
+            public:
+                Lz4Uncompressor(void *dst, size_t dst_size, const void *src, size_t src_size) : src(static_cast<const u8 *>(src)), src_size(src_size), src_offset(0), dst(static_cast<u8 *>(dst)), dst_size(dst_size), dst_offset(0) {
+                    /* ... */
+                }
+
+                void Uncompress() {
+                    while (true) {
+                        /* Read a control byte. */
+                        const u8 control = this->ReadByte();
+
+                        /* Copy what it specifies we should copy. */
+                        this->Copy(this->GetCopySize(control >> 4));
+
+                        /* If we've exceeded size, we're done. */
+                        if (this->src_offset >= this->src_size) {
+                            break;
+                        }
+
+                        /* Read the wide copy offset. */
+                        u16 wide_offset = this->ReadByte();
+                        AMS_ABORT_UNLESS(this->CanRead());
+                        wide_offset |= (this->ReadByte() << 8);
+
+                        /* Determine the copy size. */
+                        const size_t wide_copy_size = this->GetCopySize(control & 0xF);
+
+                        /* Copy bytes. */
+                        const size_t end_offset = this->dst_offset + wide_copy_size + 4;
+                        for (size_t cur_offset = this->dst_offset; cur_offset < end_offset; this->dst_offset = (++cur_offset)) {
+                            AMS_ABORT_UNLESS(wide_offset <= cur_offset);
+
+                            this->dst[cur_offset] = this->dst[cur_offset - wide_offset];
+                        }
+                    }
+                }
+            private:
+                u8 ReadByte() {
+                    return this->src[this->src_offset++];
+                }
+
+                bool CanRead() const {
+                    return this->src_offset < this->src_size;
+                }
+
+                size_t GetCopySize(u8 control) {
+                    size_t size = control;
+
+                    if (control >= 0xF) {
+                        do {
+                            AMS_ABORT_UNLESS(this->CanRead());
+                            control = this->ReadByte();
+                            size += control;
+                        } while (control == 0xFF);
+                    }
+
+                    return size;
+                }
+
+                void Copy(size_t size) {
+                    __builtin_memcpy(this->dst + this->dst_offset, this->src + this->src_offset, size);
+                    this->dst_offset += size;
+                    this->src_offset += size;
+                }
+        };
+
+    }
+
+    void Uncompress(void *dst, size_t dst_size, const void *src, size_t src_size) {
+        /* Create an execute a decompressor. */
+        Lz4Uncompressor(dst, dst_size, src, src_size).Uncompress();
+    }
+
+}

fusee_cpp/loader_stub/source/fusee_loader_uncompress.hpp

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <vapours.hpp>
+#pragma once
+
+namespace ams::nxboot::loader {
+
+    void Uncompress(void *dst, size_t dst_size, const void *src, size_t src_size);
+
+}