mirror of https://github.com/xemu-project/xemu.git
c66ffcd535
There is an informal contract between the cpu_init() functions and riscv_cpu_realize(): if cpu->env.misa_ext is zero, assume that the default settings were loaded via register_cpu_props() and do validations to set env.misa_ext. If it's not zero, skip this whole process and assume that the board somehow did everything. At this moment, all SiFive CPUs are setting a non-zero misa_ext during their cpu_init() and skipping a good chunk of riscv_cpu_realize(). This causes problems when the code being skipped in riscv_cpu_realize() contains fixes or assumptions that affects all CPUs, meaning that SiFive CPUs are missing out. To allow this code to not be skipped anymore, all the cpu->cfg.ext_* attributes needs to be set during cpu_init() time. At this moment this is being done in register_cpu_props(). The SiFive boards are setting their own extensions during cpu_init() though, meaning that they don't want all the defaults from register_cpu_props(). Let's move the contract between *_cpu_init() and riscv_cpu_realize() to register_cpu_props(). Inside this function we'll check if cpu->env.misa_ext was set and, if that's the case, set all relevant cpu->cfg.ext_* attributes, and only that. Leave the 'misa_ext' = 0 case as is today, i.e. loading all the defaults from riscv_cpu_extensions[]. register_cpu_props() can then be called by all the cpu_init() functions, including the SiFive ones. This will make all CPUs behave more in line with what riscv_cpu_realize() expects. This will also make the cpu_init() functions even more alike, but at this moment we would need some design changes in how we're initializing extensions/attributes (e.g. some CPUs are setting cfg options after register_cpu_props(), so we can't simply add the function to a common post_init() hook) to make a common cpu_init() code across all CPUs. Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20230113175230.473975-2-dbarboza@ventanamicro.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> |
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| cris | ||
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| loongarch | ||
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| microblaze | ||
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| nios2 | ||
| openrisc | ||
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| Kconfig | ||
| meson.build | ||