diff options
Diffstat (limited to 'arch/sparc/cpu/leon3/ambapp_low.S')
| -rw-r--r-- | arch/sparc/cpu/leon3/ambapp_low.S | 784 |
1 files changed, 784 insertions, 0 deletions
diff --git a/arch/sparc/cpu/leon3/ambapp_low.S b/arch/sparc/cpu/leon3/ambapp_low.S new file mode 100644 index 0000000000..2863586dc1 --- /dev/null +++ b/arch/sparc/cpu/leon3/ambapp_low.S @@ -0,0 +1,784 @@ +/* GRLIB AMBA Plug&Play information scanning implemented without + * using memory (stack) and one register window. The code scan + * the PnP info and inserts the AHB bridges/buses into register + * i0-i5. + * The code support + * - up to 6 AHB buses + * - multiple APB buses + * - support for AHB2AHB & L2CACHE bridges + * + * (C) Copyright 2010, 2015 + * Daniel Hellstrom, Cobham Gaisler, daniel@gaisler.com. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <ambapp.h> + + .seg "text" + .globl _nomem_amba_init + .globl _nomem_ambapp_find_buses + .globl _nomem_find_apb + .globl _nomem_find_ahb + +/* Overview + * ======== + * + * _nomem_amba_init - Init AMBA bus and calls _nomem_ambapp_find_buses + * _nomem_ambapp_find_buses - Scan AMBA PnP info for AHB buses/bridges and + * place them in i0-i5, see below + * _nomem_find_apb - Find one APB device identified by VENDOR:DEVICE + * ID and an index. + * _nomem_find_ahb - Find one AHB Master or Slave device identified + * by VENDOR:DEVICE ID and an index. + * init_ahb_bridges - Local function. Clears i0-i5 + * insert_ahb_bridge - Local function. Insert a new AHB bus into first + * free register in i0-i5. It also checks that the + * bus has not already been added. + * get_ahb_bridge - Local function. Get AHB bus from registers, + * return register iN, where N is defined by o0. + * + * The _nomem_find_apb and _nomem_find_ahb function requires that i0-i5 + * are populated with the AHB buses of the system. The registers are + * initialized by _nomem_ambapp_find_buses. + * + * AHB Bus result and requirements of i0-i5 + * ======================================== + * + * i0: AHB BUS0 IOAREA, no parent bus + * i1: AHB BUS1 IOAREA, parent bus is always i0 (AHB BUS0) and bridge address + * i2: AHB BUS2 IOAREA, 3-bit parent bus number and bridge address + * i3: AHB BUS3 IOAREA, 3-bit parent bus number and bridge address + * i4: AHB BUS4 IOAREA, 3-bit parent bus number and bridge address + * i5: AHB BUS5 IOAREA, 3-bit parent bus number and bridge address + * + * AHB BUS + * ------- + * Bits 31-20 (0xfff00000) contain the found bus I/O Area (AHB PnP area). + * + * 3-bit Parent bus + * ---------------- + * Bits 2-0 (0x00000007) contain parent bus number. Zero if no parent + * bus, 1 = parent is AHB BUS 0 (i0), 2 = parent is AHB BUS 1 (i1).. + * + * Bridge Address + * -------------- + * Bits 10-5 (0x000007e0) contain the index of the Bridge's PnP + * information on the parent. Since all bridges are found in the + * PnP information they all have a PnP entry. Together with the + * parent bus number the PnP entry can be found: + * PnPEntry = (BRIDGE_ADDRESS + (iN & 0xfff00000)) | 0x000ff800 + * where N is the parent bus minus one. + * + */ + +/* Function initializes the AHB Bridge I/O AREA storage. (Clears i0-i5) + * + * Arguments + * none + * + * Results + * none + * + * Clobbered + * none + */ + +init_ahb_bridges: + mov %g0, %i0 + mov %g0, %i1 + mov %g0, %i2 + mov %g0, %i3 + mov %g0, %i4 + retl + mov %g0, %i5 + +/* Function returns AHB Bridge I/O AREA for specified bus. + * + * Arguments + * - o0 = bus number + * + * Results + * - o0 = I/O AREA + * + * Clobbered + * none + */ +get_ahb_bridge: + cmp %o0, 1 + be,a L1 + mov %i0, %o0 + + cmp %o0, 2 + be,a L1 + mov %i1, %o0 + + cmp %o0, 3 + be,a L1 + mov %i2, %o0 + + cmp %o0, 4 + be,a L1 + mov %i3, %o0 + + cmp %o0, 5 + be,a L1 + mov %i4, %o0 + + cmp %o0, 6 + be,a L1 + mov %i5, %o0 + + /* o0 > 6: only 6 buses supported */ + mov %g0, %o0 +L1: + retl + nop + +/* Function adds a AHB Bridge I/O AREA to the i0-i5 registers if + * not already added. It stores the bus PnP start information. + * + * Arguments + * - o0 = AHB Bridge I/O area + * + * Results + * none + * + * Clobbered + * o2, o3 + */ +insert_ahb_bridge: + /* Check that bridge hasn't already been added */ + andn %o0, 0x7ff, %o2 + andn %i0, 0x7ff, %o3 + cmp %o3, %o2 + be L2 + andn %i1, 0x7ff, %o3 + cmp %o3, %o2 + be L2 + andn %i2, 0x7ff, %o3 + cmp %o3, %o2 + be L2 + andn %i3, 0x7ff, %o3 + cmp %o3, %o2 + be L2 + andn %i4, 0x7ff, %o3 + cmp %o3, %o2 + be L2 + andn %i5, 0x7ff, %o3 + cmp %o3, %o2 + be L2 + + /* Insert into first free posistion */ + cmp %i0, %g0 + be,a L2 + mov %o0, %i0 + + cmp %i1, %g0 + be,a L2 + mov %o0, %i1 + + cmp %i2, %g0 + be,a L2 + mov %o0, %i2 + + cmp %i3, %g0 + be,a L2 + mov %o0, %i3 + + cmp %i4, %g0 + be,a L2 + mov %o0, %i4 + + cmp %i5, %g0 + be,a L2 + mov %o0, %i5 +L2: + retl + nop + +/* FUNCTION int _nomem_find_ahb_bus( + * unsigned int bridge, + * int vendor_device, + * int index, + * void **pconf, + * int not_used, + * int option + * ) + * + * Scans the AHB Master or Slave area for a matching VENDOR:DEVICE, the + * index is decremented when a matching device is found but index is + * greater than zero. When index is zero and a matching DEVICE:VENDOR + * is found the AHB configuration address and AHB I/O area is returned. + * + * i0-i7,l0,l1,l2,l3,l4,g2,o6 is not available for use. + * o1,o5 Must be left untouched + * + * Results + * - o0 Number of found devices (1 or 0) + * - o2 is decremented for each matching VENDOR:DEVICE found, zero if found + * - o3 Address of the AHB PnP configuration entry (Only valid if o0=1) + * + * Clobbered + * - o3 (Clobbered when no device was found) + * - o4 (Number of Devices left to search) + * - o0 (Bus ID, PnP ID, Device) + */ +_nomem_find_ahb_bus: + + /* Get the number of Slaves/Masters. + * Only AHB Bus 0 has 64 AHB Masters/Slaves the + * other AHB buses has 16 slaves and 16 masters. + */ + add %g0, 16, %o4 /* Defaulting to 16 */ + andcc %o0, 0x7, %g0 /* 3-bit bus id */ + be,a .L_maxloops_detected + add %g0, 64, %o4 /* AHB Bus 0 has 64 AHB Masters/Slaves */ +.L_maxloops_detected: + + /* Get start address of AHB Slave or AHB Master area depending on what + * we are searching for. + */ + andn %o0, 0x7ff, %o0 /* Remove Bus ID and 5-bit AHB/AHB + * Bridge PnP Address to get I/O Area */ + set AMBA_CONF_AREA, %o3 + or %o3, %o0, %o3 /* Master area address */ + + cmp %o5, DEV_AHB_SLV + be,a .L_conf_area_calculated + or %o3, AMBA_AHB_SLAVE_CONF_AREA, %o3 /* Add 0x800 to get to slave area */ +.L_conf_area_calculated: + + /* Iterate over all AHB device and try to find matching DEVICE:VENDOR + * o1 - VENDOR|DEVICE + * o2 - Index + * o3 - Current AHB Device Configuration address + * o5 - Type (leave untouched) + * + * o4 - Number of AHB device left to process + * o0 - tmp + */ +.L_process_one_conf: + ld [%o3], %o0 + andn %o0, 0xfff, %o0 + cmp %o0, 0 /* No device if zero */ + beq .L_next_conf + cmp %o1, 0 /* If VENDOR:DEVICE==0, consider all matching */ + beq .L_process_ahb_dev_found + cmp %o0, %o1 /* Does VENDOR and DEVICE Match? */ + bne .L_next_conf + nop +.L_process_ahb_dev_found: + /* Found a Matching VENDOR:DEVICE, index must also match */ + cmp %o2, %g0 + bne .L_next_conf + dec %o2 + /* Index matches also, return happy with o3 set to AHB Conf Address */ + mov %g0, %o2 + retl + add %g0, 1, %o0 + +.L_next_conf: + subcc %o4, 1, %o4 /* One device has been processed, + * Are there more devices to process? */ + bne .L_process_one_conf + add %o3, AMBA_AHB_CONF_LENGH, %o3 /* Next Configuration entry */ + /* No Matching device found */ + retl + mov %g0, %o0 + +/* FUNCTION int _nomem_find_ahb( + * int unused, + * int vendor_device, + * int index, + * void **pconf, + * int *ahb_bus_index, + * int option, + * ) + * + * Find a AHB Master or AHB Slave device, it puts the address of the AHB PnP + * configuration in o3 (pconf), the I/O Area base address in o4 (pioarea). + * + * Calls _nomem_find_ahb_bus for every AHB bus. + * + * i0-i7, l0, l1, o6, g1, g4-g7 is not available for use. + * + * Arguments + * - o0 Unused + * + * Results + * - o0 Number of found devices (1 or 0) + * - o2 Decremented Index (Zero if found) + * - o3 Address of the AHB PnP configuration entry + * - o4 AHB Bus index the device was found on (if o0=1) + * - o5 Left untouched + * + * Clobbered + * - o0 (AHB Bridge and used by _nomem_find_ahb_bus) + * - o2 (index is decremented) + * - l2 (Current AHB Bus index) + * - g2 (return address) + */ +_nomem_find_ahb: + mov %o7, %g2 /* Save return address */ + /* Scan all AHB Buses found for the AHB Master/Slave matching VENDOR:DEVICE */ + clr %l2 +.L_search_next_ahb_bus: + add %l2, 1, %l2 + call get_ahb_bridge /* Get bus %l0 I/O Area */ + mov %l2, %o0 + cmp %o0, %g0 + be .L_no_device_found /* If no more AHB bus is left to be scanned, proceed */ + nop + call _nomem_find_ahb_bus /* Scan AHB bus %o0 for VENDOR:DEVICE. Index in o3 is decremented */ + nop + cmp %o0, %g0 /* If VENDOR:DEVICE was not found scan next AHB Bus */ + be .L_search_next_ahb_bus /* Do next bus is o0=0 (not found) */ + nop + /* The device was found, o0 is 1 */ + mov %g2, %o7 /* Restore return address */ + retl + mov %l2, %o4 /* The AHB bus index the device was found on */ + + /* No device found matching */ +.L_no_device_found: + mov %g2, %o7 /* Restore return address */ + retl + mov %g0, %o0 + + +/* FUNCTION int _nomem_find_apb_bus( + * int apbmst, + * int vendor_device, + * int index, + * void **pconf + * ) + * + * Find a APB Slave device, it puts the address of the APB PnP configuration + * in o3 (pconf). + * + * Calls _nomem_find_ahb_bus for every AHB bus searching for AHB/APB Bridges. + * The AHB/APB bridges are AHB Slaves with ID GAISLER_APBMST. + * + * Results + * - o0 Number of found devices (1 or 0) + * - o2 Decremented Index + * - o3 Address of the found APB device PnP configuration entry + * + * Clobbered + * - o5 PnP VENDOR:DEVICE ID + */ + +_nomem_find_apb_bus: + set AMBA_CONF_AREA, %o3 + or %o0, %o3, %o3 /* Calc start of APB device PnP info */ + add %g0, 16, %o0 /* o0, number of APB Slaves left to scan */ +.L_process_one_apb_conf: + ld [%o3], %o5 + andn %o5, 0xfff, %o5 + cmp %o5, 0 /* No device if zero */ + beq .L_process_apb_dev_not_found + cmp %o1, 0 /* If VENDOR:DEVICE == -1, consider all matching */ + beq .L_process_apb_dev_found + cmp %o1, %o5 /* Found VENDOR:DEVICE */ + bne .L_process_apb_dev_not_found + nop + +.L_process_apb_dev_found: + /* Found matching device, compare index */ + cmp %o2, %g0 + bne .L_process_apb_dev_not_found + dec %o2 + /* Matching index and VENDOR:DEVICE */ + retl + add %g0, 1, %o0 + +.L_process_apb_dev_not_found: + subcc %o0, 1, %o0 + bne .L_process_one_apb_conf + add %o3, 8, %o3 + retl + mov %g0, %o0 + +/* FUNCTION int _nomem_find_apb( + * int unused, + * int vendor_device, + * int index, + * void **pconf, + * int *ahb_bus_index + * ) + * + * Find a APB Slave device, it puts the address of the APB PnP configuration + * in o3 (pconf), the APB Master I/O Area base address in o4 (papbarea). + * + * Calls _nomem_find_ahb_bus for every AHB bus searching for AHB/APB Bridges. + * The AHB/APB bridges are AHB Slaves with ID GAISLER_APBMST. + * + * i0-i7, l0, l1, o6 is not available for use. + * + * Arguments + * - o0 Unused + * + * Results + * - o0 Number of found devices (1 or 0) + * - o2 Decremented Index if not found + * - o3 Address of the APB PnP configuration entry + * - o4 AHB Bus index of APB Bridge/APB Device + * + * Clobbered + * - o0 (AHB Bridge) + * - o2 (index is decremented) + * - l2 (APB DEV Index [7..4] : APBMST AHB Index [3..0]) + * - l3 (Current AHB Bus index) + * - l4 (temporary storage for APB VENDOR:DEVICE) + * - o5 (AHB Slave ID) + * - o0 (clobbered by _nomem_find_ahb_bus) + * - g2 (Return address) + */ +_nomem_find_apb: + /* Scan all AHB Buses found for AHB/APB Bridges */ + mov %o7, %g2 /* Save return address */ + mov %o1, %l4 /* Save APB VENDOR:DEVICE */ + sll %o2, 4, %l2 /* APB MST index = 0 */ + add %g0, 1, %l3 /* AHB Bus index = 0 */ +.L2_search_next_ahb_bus: + call get_ahb_bridge /* Get bus %l3 I/O Area */ + mov %l3, %o0 + cmp %o0, %g0 + be .L2_no_device_found /* If no more AHB bus is left to be scanned, proceed */ + add %g0, DEV_AHB_SLV, %o5 /* Search for AHB Slave */ + sethi %hi(AMBA_PNP_ID(VENDOR_GAISLER, GAISLER_APBMST)), %o1 + call _nomem_find_ahb_bus /* Scan AHB bus %o0 for VENDOR:DEVICE. Index in o3 is decremented */ + and %l2, 0xf, %o2 /* Set APBMST index */ + cmp %o0, %g0 /* If no AHB/APB Bridge was not found, scan next AHB Bus */ + be .L_no_apb_bridge_found /* Do next bus */ + nop + + /* The AHB/APB Bridge was found. + * Search for the requested APB Device on the APB bus using + * find_apb_bus, it will decrement the index. + */ + ld [%o3 + AMBA_AHB_MBAR0_OFS], %o3 + sll %o3, 16, %o0 + and %o0, %o3, %o0 /* Address AND Address Mask */ + sethi %hi(0xfff00000), %o3 + and %o0, %o3, %o0 /* AHB/APB Bridge address */ + + srl %l2, 4, %o2 /* APB DEV Index */ + call _nomem_find_apb_bus + mov %l4, %o1 /* APB VENDOR:DEVICE */ + cmp %o0, %g0 + be .L_apb_dev_not_found + mov %g2, %o7 /* Restore return address */ + /* APB Device found + * o0 1 + * o2 Index is decremented to zero + * o3 APB configuration address, + * o4 APB Bridge Configuration address. + */ + mov %g0, %o2 + retl + mov %l3, %o4 + +.L_apb_dev_not_found: + /* Update APB DEV Index by saving output from find_apb_bus + * (index parameter) into bits [31..4] in L2. + */ + sll %o2, 4, %o2 + and %l2, 0xf, %l2 + or %o2, %l2, %l2 + /* Try finding the next AHB/APB Bridge on the same AHB bus + * to find more APB devices + */ + ba .L2_search_next_ahb_bus /* Find next AHB/APB bridge */ + inc %l2 + +.L_no_apb_bridge_found: + inc %l3 /* Next AHB Bus */ + ba .L2_search_next_ahb_bus /* Process next AHB bus */ + andn %l2, 0xf, %l2 /* Start at APB Bridge index 0 at every AHB Bus */ + /* No device found matching */ +.L2_no_device_found: + mov %g2, %o7 /* Restore return address */ + srl %l2, 4, %o2 /* APB DEV Index */ + retl + mov %g0, %o0 + + + +/* FUNCTION _nomem_amba_scan_gaisler_ahb2ahb_bridge(unsigned int bridge, int bus) + * + * Constraints: + * - o1 may not be used + * - o0, o2, o3 may be used. + * + * Arguments + * - o0 PnP Address of Bridge AHB device + * - o2 PnP ID of AHB device + * + * Results + * - o0 Address of new bus PnP area or a 1 if AHB device is no bridge + * + * Clobbered + * - o0, o2 + * + */ +_nomem_amba_scan_gaisler_ahb2ahb_bridge: + andn %o2, 0xfff, %o2 + sethi %hi(AMBA_PNP_ID(VENDOR_GAISLER,GAISLER_AHB2AHB)), %o3 + cmp %o2, %o3 + beq .L_is_ahb2ahb_bridge + nop + + retl + add %g0, 1, %o0 + +.L_is_ahb2ahb_bridge: + /* Found a GAISLER AHB2AHB bridge */ + retl + ld [%o0 + AMBA_AHB_CUSTOM1_OFS], %o0 /* Get address of bridge PnP area */ + + +/* FUNCTION _nomem_amba_scan_gaisler_l2cache_bridge(unsigned int bridge, int bus) + * + * Constraints: + * - o1 may not be used + * - o0, o2, o3 may be used. + * + * Arguments + * - o0 PnP Address of Bridge AHB device + * - o2 PnP ID of AHB device + * + * Results + * - o0 Address of new bus PnP area or a 1 if AHB device is no bridge + * + * Clobbered + * - o0, o2 + * + */ +_nomem_amba_scan_gaisler_l2cache_bridge: + andn %o2, 0xfff, %o2 + sethi %hi(AMBA_PNP_ID(VENDOR_GAISLER,GAISLER_L2CACHE)), %o3 + cmp %o2, %o3 + beq .L_is_l2cache_bridge + nop + + retl + add %g0, 1, %o0 + +.L_is_l2cache_bridge: + /* Found a GAISLER l2cache bridge */ + retl + ld [%o0 + AMBA_AHB_CUSTOM1_OFS], %o0 /* Get address of bridge PnP area */ + + +/* FUNCTION _nomem_amba_scan(unsigned int bridge, int bus) + * + * Constraints: + * i0-i7, l0 is used by caller + * o5-o7 may not be used. + * + * Arguments + * - o0 Bridge Information: I/O AREA and parent bus + * - o1 Bus + * + * Results + * - o0 Number of AHB bridges found + * + * Clobbered + * - o0 (Current AHB slave conf address) + * - o2 (Used by insert_bridge) + * - o3 (Used by insert_bridge) + * - l1 (Number of AHB Slaves left to process) + * - l2 (Current AHB slave conf address) + * - g2 (Return address) + */ +_nomem_amba_scan: + mov %o7, %g2 /* Save return address */ + set 16, %l1 + cmp %o1, 1 + be,a .L2_maxloops_detected + add %g0, 64, %l1 +.L2_maxloops_detected: + + /* Clear 3-bit parent bus from bridge to get I/O AREA, then or + * (AMBA_CONF_AREA | AMBA_AHB_SLAVE_CONF_AREA) to get first AHB slave + * conf address. + */ + andn %o0, 0x7ff, %o0 + set (AMBA_CONF_AREA | AMBA_AHB_SLAVE_CONF_AREA), %l2 + or %o0, %l2, %l2 + + /* Scan AHB Slave area for AHB<->AHB bridges. For each AHB device + * all "bridge drivers" are called, the driver function interface: + * + * Input: + * - o0 PnP Address of Bridge AHB device + * - o2 PnP ID of AHB device + * Return values: + * - o0 Address of new bus PnP area, returning a 1 in o2 means not found + * + * Constraints: + * - o1 may not be used + * - o0, o2, o3 may be used. + * + */ +.L_scan_one_ahb_slave: + ld [%l2], %o2 + + cmp %o2, %g0 + beq .L_scan_next_ahb_slave + nop + + /* Call the GAISLER AHB2AHB bridge driver */ + call _nomem_amba_scan_gaisler_ahb2ahb_bridge + mov %l2, %o0 + cmp %o0, 1 + bne .L_found_bridge + ld [%l2], %o2 + + /* Call the GAISLER L2CACHE bridge driver */ + call _nomem_amba_scan_gaisler_l2cache_bridge + mov %l2, %o0 + cmp %o0, 1 + bne .L_found_bridge + ld [%l2], %o2 + + /* Insert next bridge "driver" function here */ + + + /* The PnP ID did not match a bridge - a new bus was not found ==> + * step to next AHB device */ + ba .L_scan_next_ahb_slave + nop + + /* Add Found bus */ +.L_found_bridge: + and %l2, 0x7e0, %o2 + or %o2, %o0, %o0 /* Add AHB/AHB Bridge PnP address */ + call insert_ahb_bridge /* Insert Bridge into found buses storage */ + or %o1, %o0, %o0 /* Add parent bus LSB 3-bits */ + +.L_scan_next_ahb_slave: + /* More Slaves to process? */ + subcc %l1, 1, %l1 + bne .L_scan_one_ahb_slave + add %l2, AMBA_AHB_CONF_LENGH, %l2 + + /* No more AHB devices to process */ + mov %g2, %o7 /* Restore return address */ + retl + nop + +/* FUNCTION _nomem_ambapp_find_buses(unsigned int ioarea) + * + * Find AMBA AHB buses. + * + * Constraints: + * i6-i7, l7 is used by caller + * + * Arguments + * - o0 Bridge Information: I/O AREA and parent bus + * + * Results + * - o0 Number of AHB bridges found + * - i0-i5 initialized + * + * Clobbered + * - o0 (Current AHB slave conf address) + * - o2 (Used by insert_bridge) + * - o3 (Used by insert_bridge) + * - l0 (Current AHB Bus) + * - l1 (Used by nomem_amba_scan) + * - l2 (Used by nomem_amba_scan) + * - l3 (Used by nomem_amba_scan) + * - l4 (Used by nomem_amba_scan) + * + * - g1 (level 1 return address) + * - g2 (Used by nomem_amba_scan) + */ +_nomem_ambapp_find_buses: + mov %o7, %g1 /* Save return address */ + + /* Initialize AHB Bus storage */ + call init_ahb_bridges + nop + + /* Insert AHB Bus 0 */ + call insert_ahb_bridge + nop /* Argument already prepared by caller */ + + /* Scan AHB Bus 0 for AHB Bridges */ + call _nomem_amba_scan + add %g0, 1, %o1 + + /* Scan all AHB Buses found for more AHB Bridges */ + add %g0, 2, %l0 +.L100_search_next_ahb_bus: + call get_ahb_bridge /* Get bus %l0 I/O Area */ + mov %l0, %o0 + cmp %o0, %g0 + be .L100_return /* If no more AHB bus is left to be scanned, proceed */ + nop + call _nomem_amba_scan /* Scan bus %l0 for AHB Bridges. i0-i7,l0 is used */ + mov %l0, %o1 /* I/O AREA untouched in o0 */ + ba .L100_search_next_ahb_bus /* Do next bus */ + add %l0, 1, %l0 + +.L100_return: + mov %g1, %o7 + retl + nop + + +/* FUNCTION _nomem_amba_init(unsigned int ioarea) + * + * Find all AHB buses + * + * Constraints: + * i6, i7, o6, o7, l7, l6, g3, g4, g5, g6, g7 is used by caller + * + * Arguments + * - o0 Bridge Information: I/O AREA and parent bus + * + * Results + * - o0 Number of AHB bridges found + * + * Clobbered + * - l0, l1, l2, l3, l4, g1, g2 (used by _nomem_ambapp_find_buses) + * - o0, o1, o2, o3 (Used as arguments) + * - o5 (return address) + * - g1 (level 1 return address) + * - g2 (level 2 return address) + */ +_nomem_amba_init: + mov %o7, %o5 /* Save return address, o5 not used */ + + /* Scan for buses, it will init i0-i5 */ + call _nomem_ambapp_find_buses + nop + + mov %o5, %o7 + retl + nop + +/* Call tree and their return address register + * + *_nomem_amba_scan (g1) + * -> init_ahb_bridges (o7) + * -> insert_ahb_bridge (o7) + * -> _nomem_amba_scan (g2) + * -> insert_ahb_bridge (o7) + * -> get_ahb_bridge (o7) + * + * + * -> _nomem_find_apb (g2) + * -> get_ahb_bridge (o7) + * -> _nomem_find_ahb_bus (o7) + * -> _nomem_find_apb_bus (o7) + * -> _nomem_find_ahb (g2) + * -> get_ahb_bridge (o7) + * -> _nomem_find_ahb_bus (o7) + * -> mem_handler.func() (o7) + * + */ |
