* [PATCH 0/2] riscv: Fixes for XIP support @ 2022-01-20 15:33 Myrtle Shah 2022-01-20 15:33 ` [PATCH 1/2] riscv: Fix XIP_FIXUP_FLASH_OFFSET Myrtle Shah 2022-01-20 15:33 ` [PATCH 2/2] riscv/mm: Add some missing XIP_FIXUPs Myrtle Shah 0 siblings, 2 replies; 3+ messages in thread From: Myrtle Shah @ 2022-01-20 15:33 UTC (permalink / raw) To: linux-riscv, paul.walmsley, palmer; +Cc: linux-kernel Apologies for the spam, resending as this appeared to break the first time. These are some initial patches to bugs I found attempting to get a XIP kernel working on hardware: - 32-bit VexRiscv processor - kernel in SPI flash, at 0x00200000 - 16MB of RAM at 0x10000000 - MMU enabled The system isn't actually booting yet; but at least the initial memory management setup completes with these patches as opposed to crashing almost straight away. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/2] riscv: Fix XIP_FIXUP_FLASH_OFFSET 2022-01-20 15:33 [PATCH 0/2] riscv: Fixes for XIP support Myrtle Shah @ 2022-01-20 15:33 ` Myrtle Shah 2022-01-20 15:33 ` [PATCH 2/2] riscv/mm: Add some missing XIP_FIXUPs Myrtle Shah 1 sibling, 0 replies; 3+ messages in thread From: Myrtle Shah @ 2022-01-20 15:33 UTC (permalink / raw) To: linux-riscv, paul.walmsley, palmer; +Cc: linux-kernel There were several problems with the calculation. Not only was an 'and' being computed into t1 but thrown away; but the 'and' itself would cause problems if the granularity of the XIP physical address was less than XIP_OFFSET - in my case I had the kernel image at 2MB in SPI flash. I believe this approach is more generic. Fixes: f9ace4ede49b ("riscv: remove .text section size limitation for XIP") Signed-off-by: Myrtle Shah <gatecat@ds0.me> --- arch/riscv/kernel/head.S | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 604d60292dd8..b1ca65abeb1e 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -21,14 +21,13 @@ add \reg, \reg, t0 .endm .macro XIP_FIXUP_FLASH_OFFSET reg - la t1, __data_loc - li t0, XIP_OFFSET_MASK - and t1, t1, t0 - li t1, XIP_OFFSET - sub t0, t0, t1 - sub \reg, \reg, t0 + la t0, __data_loc + REG_L t1, _xip_phys_offset + sub \reg, \reg, t1 + add \reg, \reg, t0 .endm _xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET +_xip_phys_offset: .dword CONFIG_XIP_PHYS_ADDR + XIP_OFFSET #else .macro XIP_FIXUP_OFFSET reg .endm -- 2.34.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/2] riscv/mm: Add some missing XIP_FIXUPs 2022-01-20 15:33 [PATCH 0/2] riscv: Fixes for XIP support Myrtle Shah 2022-01-20 15:33 ` [PATCH 1/2] riscv: Fix XIP_FIXUP_FLASH_OFFSET Myrtle Shah @ 2022-01-20 15:33 ` Myrtle Shah 1 sibling, 0 replies; 3+ messages in thread From: Myrtle Shah @ 2022-01-20 15:33 UTC (permalink / raw) To: linux-riscv, paul.walmsley, palmer; +Cc: linux-kernel Signed-off-by: Myrtle Shah <gatecat@ds0.me> --- arch/riscv/mm/init.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 0624c68331d8..eeafefd1c2b3 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -41,6 +41,7 @@ phys_addr_t phys_ram_base __ro_after_init; EXPORT_SYMBOL(phys_ram_base); #ifdef CONFIG_XIP_KERNEL +#define phys_ram_base (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base)) extern char _xiprom[], _exiprom[], __data_loc; #endif @@ -248,6 +249,7 @@ pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); #ifdef CONFIG_XIP_KERNEL +#define riscv_pfn_base (*(unsigned long *)XIP_FIXUP(&riscv_pfn_base)) #define trampoline_pg_dir ((pgd_t *)XIP_FIXUP(trampoline_pg_dir)) #define fixmap_pte ((pte_t *)XIP_FIXUP(fixmap_pte)) #define early_pg_dir ((pgd_t *)XIP_FIXUP(early_pg_dir)) -- 2.34.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv ^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-01-20 15:34 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2022-01-20 15:33 [PATCH 0/2] riscv: Fixes for XIP support Myrtle Shah 2022-01-20 15:33 ` [PATCH 1/2] riscv: Fix XIP_FIXUP_FLASH_OFFSET Myrtle Shah 2022-01-20 15:33 ` [PATCH 2/2] riscv/mm: Add some missing XIP_FIXUPs Myrtle Shah
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