From 5965cba3dc1fc48b1a1734fc21c05950ccc7cc4f Mon Sep 17 00:00:00 2001 From: "Ronald G. Minnich" Date: Wed, 19 Oct 2016 08:07:13 -0700 Subject: RISCV: Clean up the common architectural code This version of coreboot successfully starts a Harvey (Plan 9) kernel as a payload, entering main() with no supporting assembly code for startup. The Harvey port is not complete so it just panics but ... it gets started. We provide a standard payload function that takes a pointer argument and makes the jump from machine to supervisor mode; the days of kernels running in machine mode are over. We do some small tweaks to the virtual memory code. We temporarily disable two functions that won't work on some targets as register numbers changed between 1.7 and 1.9. Once lowrisc catches up we'll reenable them. We add the PAGETABLES to the memlayout.ld and use _pagetables in the virtual memory setup code. We now use the _stack and _estack from memlayout so we know where things are. As time goes on maybe we can kill all the magic numbers. Change-Id: I6caadfa9627fa35e31580492be01d4af908d31d9 Signed-off-by: Ronald G. Minnich Reviewed-on: https://review.coreboot.org/17058 Tested-by: build bot (Jenkins) Reviewed-by: Furquan Shaikh --- src/arch/riscv/virtual_memory.c | 46 ++++++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 14 deletions(-) (limited to 'src/arch/riscv/virtual_memory.c') diff --git a/src/arch/riscv/virtual_memory.c b/src/arch/riscv/virtual_memory.c index be8b4884d4..999d73cec8 100644 --- a/src/arch/riscv/virtual_memory.c +++ b/src/arch/riscv/virtual_memory.c @@ -21,6 +21,7 @@ #include #include #include +#include pte_t* root_page_table; @@ -94,7 +95,7 @@ static void print_page_table_at(pte_t *pt, intptr_t virt_addr, int level) /* Print the page table structures to the console */ void print_page_table(void) { - print_page_table_at(root_page_table, 0, 0); + print_page_table_at((void *)(read_csr(sptbr) << RISCV_PGSHIFT), 0, 0); } void flush_tlb(void) @@ -115,17 +116,17 @@ pte_t ptd_create(uintptr_t ppn) pte_t pte_create(uintptr_t ppn, int prot, int user) { pte_t pte = (ppn << PTE_PPN_SHIFT) | PTE_R | PTE_V; - if (prot & PROT_WRITE) + if (prot & PTE_W) pte |= PTE_W; - if (prot & PROT_EXEC) + if (prot & PTE_X) pte |= PTE_X; if (user) pte |= PTE_U; return pte; } -void init_vm(uintptr_t virtMemStart, uintptr_t physMemStart, uintptr_t pageTableStart) { - pte_t* sbi_pt = (pte_t*) pageTableStart; +void init_vm(uintptr_t virtMemStart, uintptr_t physMemStart, pte_t *sbi_pt) +{ memset(sbi_pt, 0, RISCV_PGSIZE); // need to leave room for sbi page uintptr_t memorySize = 0x7F000000; // 0xFFF... - 0xFFFFFFFF81000000 - RISCV_PGSIZE @@ -147,21 +148,32 @@ void init_vm(uintptr_t virtMemStart, uintptr_t physMemStart, uintptr_t pageTable int l2_shift = RISCV_PGLEVEL_BITS + RISCV_PGSHIFT; size_t l2_idx = (virtMemStart >> l2_shift) & ((1 << RISCV_PGLEVEL_BITS)-1); l2_idx += ((vaddr - virtMemStart) >> l2_shift); - middle_pt[l2_idx] = pte_create(paddr >> RISCV_PGSHIFT, PROT_READ|PROT_WRITE|PROT_EXEC, 0); + middle_pt[l2_idx] = pte_create(paddr >> RISCV_PGSHIFT, + PTE_U|PTE_R|PTE_W|PTE_X, 0); } // map SBI at top of vaddr space - uintptr_t num_sbi_pages = 1; // only need to map a single page for sbi interface + // only need to map a single page for sbi interface + uintptr_t num_sbi_pages = 1; uintptr_t sbiStartAddress = (uintptr_t) &sbi_page; uintptr_t sbiAddr = sbiStartAddress; for (uintptr_t i = 0; i < num_sbi_pages; i++) { uintptr_t idx = (1 << RISCV_PGLEVEL_BITS) - num_sbi_pages + i; - sbi_pt[idx] = pte_create(sbiAddr >> RISCV_PGSHIFT, PROT_READ|PROT_EXEC, 0); + sbi_pt[idx] = pte_create(sbiAddr >> RISCV_PGSHIFT, + PTE_R|PTE_X, 0); sbiAddr += RISCV_PGSIZE; } pte_t* sbi_pte = middle_pt + ((num_middle_pts << RISCV_PGLEVEL_BITS)-1); *sbi_pte = ptd_create((uintptr_t)sbi_pt >> RISCV_PGSHIFT); + // IO space. + root_pt[0] = pte_create(0, PTE_W|PTE_R, 0); + root_pt[1] = pte_create(0x40000000>>RISCV_PGSHIFT, + PTE_W|PTE_R, 0); + + // Start of RAM + root_pt[2] = pte_create(0x80000000>>RISCV_PGSHIFT, + PTE_W|PTE_R, 0); mb(); root_page_table = root_pt; uintptr_t ptbr = ((uintptr_t) root_pt) >> RISCV_PGSHIFT; @@ -185,12 +197,13 @@ void initVirtualMemory(void) { printk(BIOS_DEBUG, "-----------------------------\n"); } + // TODO: Figure out how to grab this from cbfs printk(BIOS_DEBUG, "Initializing virtual memory...\n"); - uintptr_t physicalStart = 0x90000000; // TODO: Figure out how to grab this from cbfs - uintptr_t virtualStart = 0xffffffff80000000; - uintptr_t pageTableStart = 0x91400000; - init_vm(virtualStart, physicalStart, pageTableStart); + uintptr_t physicalStart = 0x81000000; + uintptr_t virtualStart = 0xffffffff81000000; + init_vm(virtualStart, physicalStart, (pte_t *)_pagetables); mb(); + flush_tlb(); #if IS_ENABLED(CONFIG_DEBUG_PRINT_PAGE_TABLES) printk(BIOS_DEBUG, "Finished initializing virtual memory, starting walk...\n"); @@ -220,7 +233,12 @@ void mstatus_init(void) | (1 << CAUSE_USER_ECALL) ); + /* Enable all user/supervisor-mode counters */ - write_csr(mscounteren, 0b111); - write_csr(mucounteren, 0b111); + /* We'll turn these on once lowrisc gets their bitstream up to + * 1.9. Right now there's no agreement on the values for these + * architectural registers. + */ + //write_csr(mscounteren, 0b111); + //write_csr(mucounteren, 0b111); } -- cgit v1.2.3