Hi Frederic, On 4/19/19 12:18 PM, KONRAD Frederic wrote: > This adds a little bootloader to the leon3_machine when a ram image is > given through the kernel parameter and no bios are provided: > * The UART transmiter is enabled. > * The TIMER is initialized. > > Signed-off-by: KONRAD Frederic <frederic.kon...@adacore.com> > --- > hw/sparc/leon3.c | 80 > +++++++++++++++++++++++++++++++++++++++++++++++++------- > 1 file changed, 70 insertions(+), 10 deletions(-) > > diff --git a/hw/sparc/leon3.c b/hw/sparc/leon3.c > index 774639a..2c6f486 100644 > --- a/hw/sparc/leon3.c > +++ b/hw/sparc/leon3.c > @@ -1,7 +1,7 @@ > /* > * QEMU Leon3 System Emulator > * > - * Copyright (c) 2010-2011 AdaCore > + * Copyright (c) 2010-2019 AdaCore > * > * Permission is hereby granted, free of charge, to any person obtaining a > copy > * of this software and associated documentation files (the "Software"), to > deal > @@ -44,6 +44,8 @@ > #define CPU_CLK (40 * 1000 * 1000) > > #define PROM_FILENAME "u-boot.bin" > +#define LEON3_PROM_OFFSET (0x00000000) > +#define LEON3_RAM_OFFSET (0x40000000)
I'd have split this patch in 2, first add/use these definitions, then the bootloader code, but that's OK. > > #define MAX_PILS 16 > > @@ -53,6 +55,55 @@ typedef struct ResetData { > target_ulong sp; /* initial stack pointer */ > } ResetData; > > +static uint32_t *gen_write_to_addr(uint32_t *code, hwaddr addr, uint32_t val) Can you rename that gen_store_u32()? If you prefer gen_write_to_addr() that's fine. > +{ > + stl_p(code++, 0x82100000); /* mov %g0, %g1 */ > + stl_p(code++, 0x84100000); /* mov %g0, %g2 */ > + stl_p(code++, 0x03000000 + > + extract32(addr, 10, 22)); > + /* sethi %hi(addr), %g1 */ > + stl_p(code++, 0x82106000 + > + extract32(addr, 0, 10)); > + /* or %g1, addr, %g1 */ > + stl_p(code++, 0x05000000 + > + extract32(val, 10, 22)); > + /* sethi %hi(val), %g2 */ > + stl_p(code++, 0x8410a000 + > + extract32(val, 0, 10)); > + /* or %g2, val, %g2 */ > + stl_p(code++, 0xc4204000); /* st %g2, [ %g1 ] */ > + > + return code; > +} > + > +/* > + * When loading a kernel in RAM the machine is expected to be in a different > + * state (eg: initialized by the bootloader). This little code reproduces > + * this behavior. > + */ > +static void write_bootloader(CPUSPARCState *env, uint8_t *base, > + hwaddr kernel_addr) > +{ > + uint32_t *p = (uint32_t *) base; > + > + /* Initialize the UARTs */ > + p = gen_write_to_addr(p, 0x80000108, 3); Can you add comments? Here are the notes I took while reviewing, they might be enough: // *UART_CONTROL = UART_RECEIVE_ENABLE | UART_TRANSMIT_ENABLE; > + > + /* Initialize the TIMER 0 */ > + p = gen_write_to_addr(p, 0x80000304, 39); // *GPTIMER_SCALER_RELOAD = 40 - 1; > + p = gen_write_to_addr(p, 0x80000314, 0xFFFFFFFE); // *GPTIMER0_COUNTER_RELOAD = 0xFFFE; > + p = gen_write_to_addr(p, 0x80000318, 3); // *GPTIMER0_CONFIG = GPTIMER_ENABLE | GPTIMER_RESTART; > + > + /* JUMP to the entry point */ > + stl_p(p++, 0x82100000); /* mov %g0, %g1 */ > + stl_p(p++, 0x03000000 + extract32(kernel_addr, 10, 22)); > + /* sethi %hi(kernel_addr), %g1 */ > + stl_p(p++, 0x82106000 + extract32(kernel_addr, 0, 10)); > + /* or kernel_addr, %g1 */ > + stl_p(p++, 0x81c04000); /* jmp %g1 */ > + stl_p(p++, 0x01000000); /* nop */ > +} Thanks for adding write_bootloader(), I really appreciate your effort. With the comments: Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> > + > static void main_cpu_reset(void *opaque) > { > ResetData *s = (ResetData *)opaque; > @@ -131,11 +182,12 @@ static void leon3_generic_hw_init(MachineState *machine) > /* Reset data */ > reset_info = g_malloc0(sizeof(ResetData)); > reset_info->cpu = cpu; > - reset_info->sp = 0x40000000 + ram_size; > + reset_info->sp = LEON3_RAM_OFFSET + ram_size; > qemu_register_reset(main_cpu_reset, reset_info); > > /* Allocate IRQ manager */ > - grlib_irqmp_create(0x80000200, env, &cpu_irqs, MAX_PILS, > &leon3_set_pil_in); > + grlib_irqmp_create(0x80000200, env, &cpu_irqs, MAX_PILS, > + &leon3_set_pil_in); > > env->qemu_irq_ack = leon3_irq_manager; > > @@ -148,13 +200,13 @@ static void leon3_generic_hw_init(MachineState *machine) > } > > memory_region_allocate_system_memory(ram, NULL, "leon3.ram", ram_size); > - memory_region_add_subregion(address_space_mem, 0x40000000, ram); > + memory_region_add_subregion(address_space_mem, LEON3_RAM_OFFSET, ram); > > /* Allocate BIOS */ > prom_size = 8 * MiB; > memory_region_init_ram(prom, NULL, "Leon3.bios", prom_size, > &error_fatal); > memory_region_set_readonly(prom, true); > - memory_region_add_subregion(address_space_mem, 0x00000000, prom); > + memory_region_add_subregion(address_space_mem, LEON3_PROM_OFFSET, prom); > > /* Load boot prom */ > if (bios_name == NULL) { > @@ -174,7 +226,7 @@ static void leon3_generic_hw_init(MachineState *machine) > } > > if (bios_size > 0) { > - ret = load_image_targphys(filename, 0x00000000, bios_size); > + ret = load_image_targphys(filename, LEON3_PROM_OFFSET, bios_size); > if (ret < 0 || ret > prom_size) { > error_report("could not load prom '%s'", filename); > exit(1); > @@ -198,10 +250,18 @@ static void leon3_generic_hw_init(MachineState *machine) > exit(1); > } > if (bios_size <= 0) { > - /* If there is no bios/monitor, start the application. */ > - env->pc = entry; > - env->npc = entry + 4; > - reset_info->entry = entry; > + /* > + * If there is no bios/monitor just start the application but put > + * the machine in an initialized state through a little > + * bootloader. > + */ > + uint8_t *bootloader_entry; > + > + bootloader_entry = memory_region_get_ram_ptr(prom); > + write_bootloader(env, bootloader_entry, entry); > + env->pc = LEON3_PROM_OFFSET; > + env->npc = LEON3_PROM_OFFSET + 4; > + reset_info->entry = LEON3_PROM_OFFSET; > } > } > >