diff --git a/hw/arm/boot.c b/hw/arm/boot.c index 2a151e27ab..b0879a5e76 100644 --- a/hw/arm/boot.c +++ b/hw/arm/boot.c @@ -31,6 +31,7 @@ typedef enum { FIXUP_NONE = 0, /* do nothing */ FIXUP_TERMINATOR, /* end of insns */ FIXUP_BOARDID, /* overwrite with board ID number */ + FIXUP_BOARD_SETUP, /* overwrite with board specific setup code address */ FIXUP_ARGPTR, /* overwrite with pointer to kernel args */ FIXUP_ENTRYPOINT, /* overwrite with kernel entry point */ FIXUP_GIC_CPU_IF, /* overwrite with GIC CPU interface address */ @@ -58,8 +59,17 @@ static const ARMInsnFixup bootloader_aarch64[] = { { 0, FIXUP_TERMINATOR } }; -/* The worlds second smallest bootloader. Set r0-r2, then jump to kernel. */ +/* A very small bootloader: call the board-setup code (if needed), + * set r0-r2, then jump to the kernel. + * If we're not calling boot setup code then we don't copy across + * the first BOOTLOADER_NO_BOARD_SETUP_OFFSET insns in this array. + */ + static const ARMInsnFixup bootloader[] = { + { 0xe28fe008 }, /* add lr, pc, #8 */ + { 0xe51ff004 }, /* ldr pc, [pc, #-4] */ + { 0, FIXUP_BOARD_SETUP }, +#define BOOTLOADER_NO_BOARD_SETUP_OFFSET 3 { 0xe3a00000 }, /* mov r0, #0 */ { 0xe59f1004 }, /* ldr r1, [pc, #4] */ { 0xe59f2004 }, /* ldr r2, [pc, #4] */ @@ -131,6 +141,7 @@ static void write_bootloader(const char *name, hwaddr addr, case FIXUP_NONE: break; case FIXUP_BOARDID: + case FIXUP_BOARD_SETUP: case FIXUP_ARGPTR: case FIXUP_ENTRYPOINT: case FIXUP_GIC_CPU_IF: @@ -640,6 +651,9 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data) elf_machine = EM_AARCH64; } else { primary_loader = bootloader; + if (!info->write_board_setup) { + primary_loader += BOOTLOADER_NO_BOARD_SETUP_OFFSET; + } kernel_load_offset = KERNEL_LOAD_ADDR; elf_machine = EM_ARM; } @@ -745,6 +759,7 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data) info->initrd_size = initrd_size; fixupcontext[FIXUP_BOARDID] = info->board_id; + fixupcontext[FIXUP_BOARD_SETUP] = info->board_setup_addr; /* for device tree boot, we pass the DTB directly in r2. Otherwise * we point to the kernel args. @@ -793,6 +808,9 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data) if (info->nb_cpus > 1) { info->write_secondary_boot(cpu, info); } + if (info->write_board_setup) { + info->write_board_setup(cpu, info); + } /* Notify devices which need to fake up firmware initialization * that we're doing a direct kernel boot. diff --git a/include/hw/arm/arm.h b/include/hw/arm/arm.h index 4dcd4f9b63..9217b70eb1 100644 --- a/include/hw/arm/arm.h +++ b/include/hw/arm/arm.h @@ -87,6 +87,16 @@ struct arm_boot_info { * -pflash. It also implies that fw_cfg_find() will succeed. */ bool firmware_loaded; + + /* Address at which board specific loader/setup code exists. If enabled, + * this code-blob will run before anything else. It must return to the + * caller via the link register. There is no stack set up. Enabled by + * defining write_board_setup, which is responsible for loading the blob + * to the specified address. + */ + hwaddr board_setup_addr; + void (*write_board_setup)(ARMCPU *cpu, + const struct arm_boot_info *info); }; /**